Python installation

Python 2.5 is recommended, although Python 2.4 and 2.3 are also supported. On most UNIX-like systems, you have Python installed by default. If you are on Windows or otherwise need to install Python yourself, your best place to start is probably the Python homepage. There you can download a suitable installer and get more information about the installation and Python in general.

Jython installation

Using test libraries implemented with Java or using Java tools directly requires running Robot Framework on Jython, which then requires Java Runtime Environment (JRE). The minimum required Java version is 1.4, but newer versions are recommended, as they tend to be faster with dynamic languages, such as Jython. Both Sun and IBM Java versions are supported.

Robot Framework requires Jython version 2.2. The earlier Jython version 2.1 is not compatible with Robot, and also 2.2 betas and alphas have some problems and are not supported. Unfortunately, also Jython 2.2.1 has certain Unicode problems (for more information, see http://bugs.jython.org/issue1802339 and http://bugs.jython.org/issue1032), which makes it incompatible with Robot Framework. Hopefully these problems will be fixed in future versions.

Installing Jython is a fairly easy procedure. First you need to get an installer from the Jython homepage or directly from http://downloads.sourceforge.net/jython/jython_installer-2.2.jar. Note that the installer is an executable JAR package, which you need to run as java -jar jython_installer-2.2.jar. Depending on your system, the installer runs either in the graphical or the textual mode, but in both cases, the actual installation procedure is very easy.

When installing Robot Framework, its installer tries to find the Jython executable on the system to create the jybot runner script correctly. Jython is found if:

1. Jython can be executed in the system directly (i.e. it is in the PATH).

2. An environment variable JYTHON_HOME is set and it points to the Jython installation directory.

3. The Jython installation directory is found. On Windows, it is searched from the C:\ and D:\ drives, and on other systems from the /usr/local and /opt directories. The directory is found if it is under the searched directories mentioned above, or one level deeper. For example, the following Jython installation directories would be found by the installer:

   C:\APPS\Jython2.2
   D:\Jython22
   /usr/local/jython2.2
   /opt/whatever/Jython22
   

If you plan to use Robot Framework only with Jython, you do not necessarily need Python at all. In that case, you need to perform a manual installation or have some custom installer.

Installing from source

You can get Robot Framework source code either directly from version control or as a source distribution package that needs to be extracted somewhere. In both cases, you should have a directory containing the source code, documentation, tools, templates, and so on.

You should be able to install Robot Framework to any environment where Python runs using a source distribution. The installation is done by going to the created directory from the command line, and after that running either of the following commands:

python setup.py install
python install.py install

setup.py is a standard Python installer script. It can take several parameters allowing, for example, installation into non-default locations not requiring administrative rights. It is also be used also for creating distribution packages.

install.py is a custom installation and uninstallation script for Robot Framework. When it is used for installation, it simply uses setup.py, and thus above commands are totally equivalent.

With both of these commands you get a rather long output, and something like the following text should appear at the end:

Creating Robot start-up scripts...

Installation directory: /usr/lib/python2.5/site-packages/robot
Python executable: /usr/bin/python
Jython executable: /cygdrive/c/jython2.2b2/jython.bat (found from system)
Pybot script: /usr/bin/pybot
Jybot script: /usr/bin/jybot
Rebot script: /usr/bin/rebot

Using binary installers

Use the platform-specific way of installation. For example, on Windows, double click the provided executable and follow the instructions of the graphical installer.

Manual installation

If you do not want to install Python, or for some other reason do not want to use any automatic way of installing Robot Framework, you can always do it manually following these steps:

1. Get the source code. All the code is in a directory (a module in Python) called robot. If you have a source distribution or a version control checkout, you can find it from the src directory, but you can also get it from an earlier installation.
2. Copy the source code where you want to.
3. Create the needed runner scripts. If you have a source package or a checkout, you can get templates from src/bin.

Where files are installed

When an automatic installer is used, the Robot Framework code is copied into a directory containing external Python modules. The actual location is platform-specific, but on computers with a UNIX-like operating system, it is normally something like /usr/lib/[PythonVer]/site-packages, and on Windows it is [PythonInstallationDir]\Lib\site-packages. The actual Robot Framework code is in a directory named robot.

Robot Framework runner scripts (pybot, jybot and rebot) are created and copied into another platform-specific location. On UNIX-like systems, they normally go to /usr/bin and are thus immediately available from the command line. On Windows, the operating system does not provide a similar natural place, and Python copies these scripts into [PythonInstallationDir]\Scripts.

Setting up environment

After the installation, you might want to make Robot Framework's runner scripts easily available from the command line. On UNIX-like systems, that should be the case automatically, but for example on Windows, it is not. In environments where startup scripts are not available, the directory containing them must be set to the PATH environment variable.

Setting the PATH environment variable on Windows:

1. Open Start > Settings > Control Panel > System > Advanced > Environment Variables. There are User variables and System variables, and the difference between them is that User variables affect only the current users, whereas System variables affect all users.
2. To edit the existing PATH, select Edit and add ;[PythonInstallationDir]\Scripts\ at the end of the value. Note that the leading colon (;) is important, as it separates different entries. To add a new value, select New and provide both the name and the value, this time without the colon.
3. Start a new command prompt for the changes to take effect.

Verifying installation

To verify that the installation and environment setup were successful, type:

$ pybot --version
Robot 2.0 (Python 2.5.1 on cygwin)

To verify that Robot Framework works also with Jython, type:

$ jybot --version
Robot 2.2 (Jython 2.2 on java1.6.0_03)

In both cases, the exact version and platform information can, of course, differ from these. On Jython, you may also get some notifications from Jython's package manager upon the first execution.

HTML format

In HTML files, the test data is defined in separate tables (see the example below). Robot Framework recognizes these test data tables based on the text in their first cell. Everything outside recognized tables is ignored.

Test data in HTML files can be edited with whichever editor you prefer, but a graphic editor, where you can actually see the tables, is recommended. There is also a tool called Robot IDE available that is actually designed for editing the test data.

HTML entity references (for example, ä) are supported. Additionally, any encoding can be used, assuming that it is specified in the data file. Normal HTML files must use the META element as in the example below:

<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

XHTML files should use the XML preamble as in this example:

<?xml version="1.0" encoding="Big5"?>

If no encoding is specified, Robot Framework uses ISO-8859-1 by default.

TSV format

In a TSV file, all the data is in one large table. Test data tables are recognized from an asterisk (*), followed by a normal table name. Robot Framework ignores any other asterisks in the name, so it can also be prefixed with another asterisk as in the example below. In TSV test data, everything before the first recognized table is ignored in Robot Framework.

You can create and edit TSV files in any spreadsheet program, such as Microsoft Excel. Select the tab-separated format when you save the file and remember to set the file extension to .tsv. The TSV format can be used in Robot Framework's test data for all the same purposes as HTML.

Robot Framework parses TSV data by first splitting all the content into rows and then rows into cells on the basis of the tabular characters. Spreadsheet programs sometimes surround cells with quotes (for example, "my value") and Robot Framework removes them. Possible quotes inside the data are doubled (for example, "my ""quoted"" value") and Robot Framework handles also them. If you are using a spreadsheet program to create TSV data, you do not need to pay attention to that, but if you create data programmatically, you have to add the same quotes as spreadsheets.

Ignored data

When Robot Framework parses the test data, it ignores:

• All tables that do not start with a recognized table name in the first cell
• Everything else on the first row apart from the first cell
• Data outside tables in HTML and data before the first table in TSV
• All empty rows, which means these kinds of rows can be used to make the tables more readable
• All empty cells at the end of rows; you must add a backslash (\) to prevent such cells from being ignored
• All single backslashes (\); they are used as an escape character
• All characters following a hash mark (#), if it is the first character of a cell; this means that hash marks can be used to enter comments in the test data
• All formatting in the HTML test data

When Robot Framework ignores some data, this data is not available in any resulting reports and, additionally, most tools used with Robot Framework also ignore them. To add information that is visible in Robot Framework outputs, or available to, for example, Robot IDE, place it to the documentation or other metadata of test cases or suites, or log with the Log or Comment keywords available from the BuiltIn library.

Escaping

The escape character for the Robot Framework parser is the backslash (\). The escape character can be used as follows:

• To escape special characters so that their literal values are used:
  • \${notvar} means a literal string ${notvar} that looks like a variable
  • \\ means a single backslash (for example, C:\\Temp)
  • \# means a literal hash (#) mark, even at the beginning of a cell
• To affect the parsing of whitespaces
• To prevent Robot Framework from ignoring empty cells at the end of a row (this requires \ to be in the appropriate cell).

Handling whitespace

Robot Framework handles whitespace, such as spaces, newlines and tabs, the same way as they are handled in HTML. This means that Robot Framework:

• Removes leading and trailing whitespaces in all cells.
• Changes multiple consecutive spaces into single spaces.
• Converts all newlines and tabs into spaces.

To prevent Robot Framework from parsing data according to these rules, a backslash can be used:

• Before leading spaces, for example \ some text
• Between consecutive spaces, for example text \ \ more text
• After trailing spaces, for example some text \ \
• With n to create a newline, for example first line\n2nd line
• With t to create a tab character, for example text\tmore text
• With r to create a carriage return, for example text\rmore text

Dividing test data to several rows

If a keyword requires more arguments than there are columns available, it is not necessary to add more columns. Instead, it is possible to simply have three dots (...) below the original keyword name and continue arguments there. Arguments presented like this are parsed as if they were all in one row.

The same approach works also with settings and variables taking several values. In these cases, the three dots are, of course, placed under the setting or variable name.

Additionally, values of settings that take only one value (mainly documentations) can be split to several columns. These values will be then catenated together with spaces when the test data is parsed.

All these syntaxes are illustrated in the following examples. The first three tables show tables where test data has not been split, and the following three illustrate how fewer columns are needed after splitting the data to several rows.

Basic syntax

Test cases are constructed in test case tables from the available keywords. Keywords can be imported from test libraries or resource files, or created in the keyword table of the test case file itself.

The first column in the test case table contains test case names. A test case starts from the row with something in this column and continues to the next test case name or to the end of the table. It is an error to have something between the table headers and the first test.

The second column normally has keyword names. An exception to this rule is setting variables from keyword return values, when the second and possibly also the subsequent columns contain variable names and a keyword name is located after them. In either case, columns after the keyword name contain possible arguments to the specified keyword.

Workflow tests vs. data-driven tests

In general, there are two kinds of test cases. So called workflow tests, such as the Valid Login test above, are constructed from several keywords. Their normal structure is that first the system is taken into the initial state (Open Login Page), then something is done to the system (Input Name, Input Password, Submit Credentials), and finally it is verified that the system behaved as expected (Welcome Page Should Be Open).

Another type of tests are data-driven test cases that contain only one higher-level keyword, normally created as user keywords. These kinds of tests are very useful when there is a need to test the same workflow with different input or output data, as the examples below demonstrate.

Note that in the example above, column headers have been changed to match the data. This is possible, because on the first row other cells except the first one are ignored. Additionally, backslash is used for escaping empty cells at the end of the table.

Settings in the Test Case table

Test cases can also have their own settings. Setting names are always in the second column, where keywords normally are, and their values are in the subsequent columns. Setting names have square brackets around them to distinguish them from keywords. The available settings are listed below and explained later in this section.

[Documentation]

Used for specifying a test case documentation.

[Tags]

Used for tagging test cases.

[Setup], [Teardown]

Specify test setup and teardown. Have also synonyms [Precondition] and [Postcondition], respectively.

[Timeout]

Used for setting a test case timeout. Timeouts are discussed in their own section.

Test-case-related settings in the Setting table

The Setting table can have the following test-case-related settings. These settings are mainly default values for the test-case-specific settings listed earlier.

Force Tags, Default Tags

The forced and default values for tags.

Test Setup, Test Teardown

The default values for test setup and teardown. Have also synonyms Test Precondition and Test Postcondition, respectively.

Test Timeout

The default value for test case timeout. Timeouts are discussed in their own section.

Initialization files

A test suite created from a directory can have the same settings (Documentation, Meta: <name>, Suite Setup, Suite Teardown) as a test case created from a file. Because a directory alone cannot have that kind of information, they must be placed into a special initialization file.

Initialization files have the same structure as test case files, except that they cannot have test case tables, and the overall syntax used in them is the same as in other test data files. An initialization file name must always be of the format __init__.extension, where the extension is the same as normally for test data files (for example, __init__.html or __init__.tsv). The name format is borrowed from Python, where files named in this manner denote that a directory is a module.

The main usage of initialization files is setting test-suite-related settings, but setting test-case-related settings is also possible. However, only Force Tags is generally useful, because others are only default values for the same settings in lower-level files, and even they are default values for the settings in the Test Case table.

Note that variables and keywords created in initialization files are not available elsewhere. If there is a need to share them, for example, with lower-level test suites, resource files must be used.

Using Library setting

Test libraries are normally imported using the Library setting in the Setting table and having the library name in the subsequent column. The library name is case-sensitive (it is the name of the module or class implementing the library and must be exactly correct), but any spaces in it are ignored. With Python libraries in modules or Java libraries in packages, the full name including the module or package name must be used. In those cases where the library needs arguments, they are listed in the columns after the library name. Both the library name and arguments can be set using variables.

It is possible to import test libraries in test case files, resource files and test suite initialization files. In all these cases, all the keywords in the imported library are available in that file. With resource files, those keywords are also available in other files using them.

Using Import Library keyword

Another possibility to take a test library into use is using the keyword Import Library from the BuiltIn library. This keyword takes the library name and possible arguments similarly as the Library setting. Keywords from the imported library are available in the test suite where the Import Library keyword was used. This approach is useful in cases where the library is not available when the test execution starts and only some other keywords make it available.

Library search path

Robot Framework can import a library only if the library class or module can be found from the library search path. Basically, this means that the library code and all its possible dependencies must be in PYTHONPATH or, when running tests on Jython, in a CLASSPATH. Setting the library search path is explained in a section of its own, and well-developed libraries either do that automatically or have clear instructions on how to do it.

BuiltIn library

The BuiltIn library provides a set of generic keywords needed often. The provided keywords allow functions for verifications (for example, Should Be Equal), conversions (for example, Convert To Integer) and for various other purposes (for example, Log and Sleep).

The names of the keywords in the BuiltIn library have been renamed for Robot Framework version 1.8. All the old keywords still work, but the long names (the names visible in log files) of the keywords that are deprecated begin with DeprecatedBuiltIn. (for example, DeprecatedBuiltIn.Equals).

For more information, see the BuiltIn library documentation.

OperatingSystem library

The OperatingSystem library enables various operating-system-related tasks to be performed in the system running Robot Framework. It can, among other things, execute commands (for example, Run) and check whether files exist or not (for example, File Should Exist). The idea of the library is to wrap all relevant functions from the standard Python modules os, os.path and shutil, but other related functions can also be added.

The names of the keywords in the OperatingSystem library have been renamed for Robot Framework version 1.8. All the old keywords still work, but the long names (names visible in log files) of the keywords that are deprecated begin with DeprecatedOperatingSystem. (for example, DeprecatedOperatingSystem.Fail Unless File Empty).

For more information, see the OperatingSystem library documentation.

Telnet library

The Telnet library enables testing over a Telnet connection. It has functions for logging into a Telnet server, running commands on the server and returning the output. The Telnet library extends Python's own telnetlib module and it supports several simultaneous connections.

For more information, see the Telnet library documentation.

Collections library

The Collections library provides a set of keywords for handling Python's standard list and dictionary data structures. For more information about lists and dictionaries, see Python Library Reference . The provided keywords allow functions for creating dictionaries (Create Dictionary), modifying lists and dictionaries (for example, Append To List), and checking the equality of lists and dictionaries (for example, Dictionaries Should Be Equal).

For more information, see the Collections library documentation.

Screenshot library

The Screenshot library provides a way to capture and store screenshots of the whole desktop. This library is implemented with Java AWT APIs, so it can be used only when running Robot Framework with Jython.

For more information, see the Screenshot library documentation.

Scalar variables

When scalar variables are used in the test data, they are replaced with the value they are assigned to. While scalar variables are most commonly used for simple strings, you can assign any objects, including lists, to them. The scalar variable syntax, for example ${NAME}, should be familiar to most users, as it is also used, for example, in shell scripts and Perl.

The example below illustrates the usage of scalar variables. Assuming that the variables ${GREET} and ${NAME} are available and assigned to strings Hello and world, respectively, both the example test cases are equivalent.

When a scalar variable is used as the only value in a test data cell, the scalar variable is replaced with the value it has. The value may be any object. When a scalar variable is used in a test data cell with anything else (constant strings or other variables), its value is first converted into a string and then catenated to whatever is in that cell. Converting the value into a string means that the object's method =__str__ (in Python) or toString (in Java) is called.

The example below demonstrates the difference between having a variable in a cell alone or with other content. First, let us assume that we have a variable ${STR} set to a string Hello, world! and ${OBJ} set to an instance of the following Java object:

public class MyObj {

    public String toString() {
        return "Hi, tellus!";
    }
}

With these two variables set, we then have the following test data:

Finally, when this test data is executed, different keywords receive the arguments as explained below:

• KW 1 gets a string Hello, world!
• KW 2 gets an object stored to variable ${OBJ}
• KW 3 gets a string I said "Hello, world!"
• KW 4 gets a string You said "Hi, tellus!"

List variables

List variables are compound variables that can have several values assigned to them. In short, they are always lists and can contain an unlimited number of entries (also empty lists are possible). The main benefit of list variables is that they allow you to assign a name for a larger data set. While list variables normally contain only strings, other content is also possible.

When you use a list variable in test data, then the cell that contains the variable is replaced with the content of the variable. Thus, if the list variable contains two elements, the cell containing the list variable is turned into two cells with the content of the list variable. Note that cells with list variables should not contain other content. The list variable syntax, @{NAME}, is borrowed from Perl.

Assuming that the list variable @{USER} is set to the value ['robot','secret'], the following two test cases are equivalent.

It is also possible to access a certain value from the list variable with the syntax @{NAME}[i], where "i" is the index of the selected value. Indexes start from zero, and trying to access a value with too large an index causes an error. List items accessed in this manner can be used similarly as scalar variables.

Environment variables

Robot Framework allows using environment variables in the test data using the syntax %{ENV_VAR_NAME}. They are limited to string values.

Environment variables set in the system before the test execution are available during it, and it is possible to create new ones with the keyword Set Environment Variable or delete existing ones with the keyword Delete Environment Variable, both available in the OperatingSystem library. Because environment variables are global, environment variables set in one test case can be used in other test cases executed after it. However, changes to environment variables are not effective after the test execution.

Variable table

The most common source for variables are Variable tables in test case files and resource files. Variable tables are convenient, because they allow creating variables in the same place as the rest of the test data, and the needed syntax is very simple. Their main disadvantage is that they only enable assigning variables into strings or a list of strings. If other value types are needed, variable files are probably a better option.

Variable file

Variable files are the most powerful mechanism for creating different kind of variables. It is possible to assign variables to any object using them, and they also enable creating variables dynamically. The variable file syntax and taking variable files into use is explained in section Resource and variable files.

Setting variables in command line

Variables can be set from the command line either individually with the --variable option or using a variable file with the --variablefile option. Variables set from the command line are globally available for all executed test data files, and they also override variables with the same names in the Variable table and in the imported variable files.

The syntax for setting individual variables is --variable name:value, where name is the name of the variable without ${} and value is its value. Several variables can be set by using this option several times. Only scalar variables can be set from the command line and they can only get string values. Many special characters are difficult or impossible to represent in the command line, but they can be escaped with the --escape option.

--variable EXAMPLE:value
--variable HOST:localhost:7272 --variable USER:robot
--variable ESCAPED:Qquotes_and_spacesQ --escape quot:Q --escape space:_

In the examples above, variables are set so that

• ${EXAMPLE} gets the value value
• ${HOST} and ${USER} get the values localhost:7272 and robot
• ${ESCAPED} gets the value "quotes and spaces"

Variable files are given from the command line using the syntax --variablefile path/to/variables.py. Which variables actually are created depends on which variables there are in the referenced variable file. If both variable files and individual variables are given from the command line, the latter override possible variables with the same name in the variable files.

Return values from keywords

Return values from keywords can also be set into variables. This allows communication between different keywords even in different test libraries. The syntax for a simple case is illustrated in the example below:

In the example above, the value returned by the Get X keyword is first set into the variable ${x} and then used by the Log keyword. This syntax works in all cases where a keywords returns something, and the variable is set to whatever value returned by the keyword. Having the equals sign = after the variable name is not obligatory, but recommended, because it makes the assignment more explicit.

If a keyword returns a list, it is also possible to set it into several scalar variables or into a list variable. This is possible with keywords returning Python lists or tuples or, from Robot Framework version 1.8.6 onwards, with Java keywords returning an array. In the future, it is possible to add support also for other iterables, if needed.

Assuming that the keyword Get 3 returns a list [1, 2, 3], the following variables are created:

• ${scalar} with the value [1, 2, 3]
• ${a}, ${b} and ${c} with the values 1, 2, and 3, respectively
• ${first} with the value 1, and @{rest} with the value [2, 3]
• @{list} with the value [1, 2, 3]

Variables set in this manner are otherwise similar to any other variables, but they are available only within the scope of the test case or keyword where they are created. Thus it is not possible, for example, to set a variable in one test case and use it in another. This is because, in general, automated test cases should not depend on each other, and accidentally setting a variable that is used elsewhere could cause hard-to-debug errors. If there is a genuine need for setting a variable in one test case and using it in another, use the Set Suite Variable or Set Global Variable keywords available from the BuiltIn library.

Variable scopes

Depending on where and how they are created, variables can have a global, test suite, test case or user keyword scope.

Operating-system variables

Built-in variables related to the operating system ease making the test data operating-system-agnostic.

Number variables

The variable syntax can be used for creating both integers and floating point numbers, as illustrated in the example below. This is useful when a keyword expects to get a real number as an argument.

Boolean and None/null variables

Also Boolean values and Python None and Java null can be created using the variable syntax similarly as numbers.

These variables are case-insensitive, so for example ${True} and ${true} are equivalent. Additionally, ${None} and ${null} are synonyms, because when running tests on the Jython interpreter, Jython automatically converts None and null to the correct format when necessary.

Automatic variables

Some automatic variables can also be used in the test data. These variables can have different values during the test execution and some of them are not even available all the time.

Extended variable syntax

Extended variable syntax can be used with objects set into scalar variables. This allows accessing the attributes of the object (for example, ${obj.name} or ${obj.some_attr}), and even calling its methods (for example, ${obj.get_name()} or ${obj.getSomething('arg')}.

Extended variable syntax is a powerful feature, but it should be used with care. Accessing attributes is normally not a problem, on the contrary, as one variable with an object having several attributes is often better than having several variables. On the other hand, calling methods, especially when they are used with arguments, can make the test data complicated. If that happens, it is recommended to move the code into a test library.

The most common usages of extended variable syntax are illustrated in the example below. First assume that we have the following variable file and test case:

class MyObject:

    def __init__(self, name):
        self.name = name

    def greet(self, who):
        return '%s says hello to %s' % (self.name, who)

    def __str__(self):
        return self.name

OBJECT = MyObject('Robot')
DICTIONARY = { 1: 'one', 2: 'two', 3: 'three'}

When this test data is executed, the keywords get the arguments as explained below:

• KW 1 gets string Robot
• KW 2 gets string Robot says hello to Fit
• KW 3 gets string two

The extended variable syntax is evaluated in the following order:

1. The variable is searched using the full variable name. The extended variable syntax is evaluated only, if no matching variable is found.
2. The real name of the base variable is created. The body of the name consists of all the characters after ${ until the first occurrence of a non-alphanumeric character or a space (for example, OBJECT in ${OBJECT.name} and DICTIONARY in ${DICTIONARY[2]}).
3. A variable matching the body is searched. If there is no match, an exception is raised and the test case fails.
4. The expression inside the curly brackets is evaluated as a Python expression, so the base variable name is replaced with its value. If the evaluation fails because of an invalid syntax or that the queried attribute does not exist, an exception is raised and the test fails.
5. The whole extended variable is replaced with the value returned from the evaluation.

If the object that is used is implemented with Java, the extended variable syntax allows you to access attributes using so-called bean properties. In essence, this means that if you have an object with the getName method set into a variable ${OBJ}, then the syntax ${OBJ.name} is equivalent to, but clearer than ${OBJ.getName()}. Thus the Python object used in the previous example could be replaced with the following Java implementation:

public class MyObject:

    private String name;

    public MyObject(String name) {
        name = name;
    }

    public String getName() {
        return name;
    }

    public String greet(String who) {
        return name + " says hello to " + who;
    }

    public String toString() {
        return name;
    }
}

Variables inside variables

Variables are allowed also inside variables, and when this syntax is used, variables are resolved from the inside out. For example, if you have a variable ${var${x}}, then ${x} is resolved first. If it has the value name, the final value is then the value of the variable ${varname}. There can be several nested variables, but resolving the outermost fails, if any of them does not exist.

In the example below, Do X gets the value ${JOHN_HOME} or ${JANE_HOME}, depending on if Get Name returns john or jane. If it returns something else, resolving ${${name}_HOME} fails.

Basic syntax

In many ways, the overall user keyword syntax is identical to the test case syntax. User keywords are created in keyword tables which differ from test case tables only by the name that is used to identify them. User keyword names are in the first column similarly as test cases names. Also user keywords are created from keywords, either from keywords in test libraries or other user keywords. Keyword names are normally in the second column, but when setting variables from keyword return values, they are in the subsequent columns.

Most user keywords take some arguments. This important feature is used already in the second example above, and it is explained in detail later in this section, similarly as user keyword return values.

User keywords can be created in test case files, resource files, and test suite initialization files. Keywords created in resource files are available for files using them, whereas other keywords are only available in the files where they are created.

Settings in the Keyword table

User keywords can have similar settings as test cases, and they have the same square bracket syntax separating them from keyword names. All available settings are listed below and explained later in this section.

[Documentation]

Used for setting a user keyword documentation.

[Arguments]

Specifies user keyword arguments.

[Return]

Specifies user keyword return values.

[Timeout]

Sets the possible user keyword timeout. Timeouts are discussed in a section of their own.

Positional arguments

The simplest way to specify arguments (apart from not having them at all) is using only positional arguments. In most cases, this is all that is needed.

The syntax is such that first the [Arguments] setting is given and then argument names are defined in the subsequent cells. Each argument is in its own cell, using the same syntax as with variables. The keyword must be used with as many arguments as there are argument names in its signature. Argument names should be descriptive, but the actual value is not important. It is recommended to use lower-case letters in variable names, either as ${my_arg} or ${myArg}.

Default values

Positional arguments are probably sufficient in most situations. However, sometimes it is useful to be able to have a keyword that takes a different number of arguments and has default values for those that are not given. Also user keywords allow this, and the needed new syntax does not add very much to the already discussed basic syntax. In short, default values are added to arguments, so that first there is the equals sign ( =) and then the value, for example ${arg}=default. There can be many arguments with defaults, but they all must be given after the normal positional arguments.

As all Pythonistas must have already noticed, the syntax for specifying default arguments is heavily inspired by Python syntax for function default values.

Variable number of arguments

Sometimes, but more and more seldom, even default values are not enough and there is a need for a keyword accepting any number of arguments. User keywords support also this. All that is needed is having list variables such as @{varargs} as the last argument in the keyword signature. This syntax can be combined with the previously described positional arguments and default values, and at the end the list variable gets all the leftover arguments that do not match other arguments. The list variable can thus have any number of items, even zero.

The last example above illustrates how a variable number of arguments accepted by a user keyword can be used in a For loops. This combination of two rather advanced functions can sometimes be very useful.

Again, Pythonistas probably notice that the varargs syntax is very close to the one in Python.

Taking resource files into use

Resource files are imported using the Resource setting in the Settings table. The path to the resource file is given in the cell after the setting name.

If the path is given in an absolute format, it is used directly. In other cases, the resource file is first searched relatively to the directory where the importing file is located. If the file is not found there, it is then searched from the directories in PYTHONPATH. The path can contain variables, and it is recommended to use them to make paths system-independent (for example, ${RESOURCES}/login_resources.html or ${RESOURCE_PATH}). Additionally, slashes ("/") in the path are automatically changed to backslashes ("\") on Windows.

The user keywords and variables defined in a resource file are available in the file that takes that resource file into use. Similarly available are also all keywords and variables from the libraries, resource files and variable files imported by the said resource file.

Resource file structure

The higher-level structure of resource files is the same as that of test case files otherwise, but, of course, they cannot contain Test Case tables. Additionally, the Setting table in resource files can contain only import settings (Library, Resource, and Variables). The Variable table and Keyword table are used exactly the same way as in test case files.

If several resource files have a user keyword with the same name, they must be used so that the keyword name is prefixed with the resource file name without the extension (for example, myresources.Some Keyword and common.Some Keyword). Moreover, if several resource files contain the same variable, the one that is imported first is taken into use.

Taking variable files into use

Creating variables directly

VARIABLE = "An example string"
ANOTHER_VARIABLE = "This is pretty easy!"
INTEGER = 42
STRINGS = ["one", "two", "kolme", "four"]
NUMBERS = [1, INTEGER, 3.14]

LIST__STRINGS = ["list", "of", "strings"]
LIST__MIXED = ["first value", -1.1, None, True]

from java.util import Hashtable

MAPPING = Hashtable()
MAPPING.put("one", 1)
MAPPING.put("two", 2)

MAPPING = { 'one': 1, 'two': 2}

class MyObject:
    def __init__(self, name):
        self.name = name

OBJ1 = MyObject('John')
OBJ2 = MyObject('Jane')

import os
import random
import time

USER = os.getlogin()                # current login name
RANDOM_INT = random.randint(0, 10)  # random integer in range [0,10]
CURRENT_TIME = time.asctime()       # timestamp like 'Thu Apr  6 12:45:21 2006'
if time.localtime()[3] > 12:
    AFTERNOON = True
else:
    AFTERNOON = False

import math

def get_area(diameter):
    radius = diameter / 2
    area = math.pi * radius * radius
    return area

AREA1 = get_area(1)
AREA2 = get_area(2)

import math as _math

def _get_area(diameter):
    radius = diameter / 2.0
    area = _math.pi * radius * radius
    return area

AREA1 = _get_area(1)
AREA2 = _get_area(2)

import math

__all__ = ['AREA1', 'AREA2']

def get_area(diameter):
    radius = diameter / 2.0
    area = math.pi * radius * radius
    return area

AREA1 = get_area(1)
AREA2 = get_area(2)

Getting variables from a special function

An alternative syntax for getting variables is having a special get_variables function (also camelCase syntax getVariables is possible) in the variable file. In this case, Robot Framework calls that function and it returns variables as a Python dictionary (similar to Java maps), with variable names as keys and variable values as values. Variables are considered to be scalars, unless prefixed with LIST__, and values can contain anything. The example below is identical to the first examples of creating variables directly.

def get_variables():
    variables = { "VARIABLE ": "An example string",
                  "ANOTHER_VARIABLE": "This is pretty easy!",
                  "INTEGER": 42,
                  "STRINGS": ["one", "two", "kolme", "four"],
                  "NUMBERS": [1, 42, 3.14],
                  "LIST__STRINGS": ["list", "of", "strings"],
                  "LIST__MIXED": ["first value", -1.1, None, True] }
    return variables

get_variables can also take arguments. This feature facilitates changing which variables actually are created. Arguments to the function are set just as any other arguments for a Python function, and when importing the file, arguments are specified in cells after the path to the variable file. The dummy example below illustrates this principle. In a more realistic example, the argument could be a path to an external text file or database where to read variables from.

variables1 = { 'scalar': 'Scalar variable',
               'LIST__list': ['List','variable'] }
variables2 = { 'scalar' : 'Some other value',
               'LIST__list': ['Some','other','value'],
               'extra': 'variables1 does not have this at all' }

def get_variables(arg):
    if arg == 'one':
        return variables1
    else:
        return variables2

The most notable benefit of using get_variables instead of defining variables directly as global attributes of the variable file is the ability to use arguments. On the other hand, the main drawback is that this approach always requires some actual programming.

Keyword scopes

When only a keyword name is used and there are several keywords with that name, Robot Framework attempts to determine which keyword has the highest priority based on its scope. The keyword's scope is determined on the basis of how the keyword in question is created:

1. Created as a user keyword in the same file where it is used. These keywords have the highest priority and they are always used, even if there are other keywords with the same name elsewhere.
2. Created in a resource file and imported either directly or indirectly from another resource file. This is the second-highest priority.
3. Created in an external test library. These keywords are used, if there are no user keywords with the same name. However, if there is a keyword with the same name in the standard library, a warning is displayed.
4. Created in a standard library. These keywords have the lowest priority.

Specifying a keyword explicitly

Scopes alone are not a sufficient solution, because there can be keywords with the same name in several libraries or resources, and additionally, they provide a mechanism to use only the keyword of the highest priority. In such cases, it is possible to use the full name of the keyword, where the keyword name is prefixed with the name of the resource or library and a dot is a delimiter.

With library keywords, the long format means only using the format LibraryName.Keyword Name. For example, the keyword Run from the OperatingSystem library could be used as OperatingSystem.Run, even if there was another Run keyword somewhere else. If the library is in a module or package, the full module or package name must be used (for example, com.company.Library.Some Keyword). If a custom name is given to a library using the WITH NAME syntax, the specified name must be used also in the full keyword name.

Resource files are specified in the full keyword name, similarly as library names. The name of the resource is derived from the basename of the resource file without the file extension. For example, the keyword Example in a resource file myresources.html can be used as myresources.Example. Note that this syntax does not work, if several resource files have the same basename. In such cases, either the files or the keywords must be renamed. The full name of the keyword is case-, space- and underscore-insensitive, similarly as normal keyword names.

Test case timeout

The test case timeout can be set either by using the Test Timeout setting in the Setting table or the [Timeout] setting in the Test Case table. Test Timeout in the Setting table defines a default test timeout value for all the test cases in the test suite, whereas [Timeout] in the Test Case table applies a timeout to an individual test case and overrides the possible default value.

Regardless of where the test timeout is defined, the first cell after the setting name contains the duration of the timeout. The duration must be given in Robot Framework's time format, that is, either directly in seconds or in a format like 1 minute 30 seconds. It must be noted that there is always some overhead by the framework, and timeouts shorter than one second are thus not recommended.

The default error message displayed when a test timeout occurs is Test timeout <time> exceeded. It is also possible to use custom error messages, and these messages are written into the cells after the timeout duration. The message can be split into multiple cells, similarly as documentations. Both the timeout value and the error message may contain variables.

If there is a timeout, the keyword running is stopped at the expiration of the timeout and the test case fails. However, keywords executed as test teardown are not interrupted if a test timeout occurs, because they are normally engaged in important clean-up activities. If necessary, it is possible to interrupt also these keywords with user keyword timeouts.

User keyword timeout

A timeout can be set for a user keyword using the [Timeout] setting in the Keyword table. The syntax for setting it, including how timeout values and possible custom messages are given, is identical to the syntax used with test case timeouts. If no custom message is provided, the default error message Keyword timeout <time> exceeded is used if a timeout occurs.

A user keyword timeout is applicable during the execution of that user keyword. If the total time of the whole keyword is longer than the timeout value, the currently executed keyword is stopped. User keyword timeouts are applicable also during a test case teardown, whereas test timeouts are not.

If both the test case and some of its keywords (or several nested keywords) have a timeout, the active timeout is the one with the least time left.

Normal for loop

In a normal For loop, one variable is assigned into a list of values, one value per iteration. The syntax starts with :FOR, where colon is required to separate the syntax from normal keywords. The next cell contains the loop variable, the subsequent cell must have IN, and the final cells contain values over which to iterate.

The keywords used in the For loop are on the next rows and they must be indented one cell to the right. The For loop ends when the indentation returns back to normal or the table ends. Having nested For loops directly is not supported, but it is possible to use a user keyword inside a For loop and have another For loop there.

The For loop in Example 1 above is executed twice, so that first the loop variable ${animal} has the value cat and then dog. The loop consists of two Log keywords. In the second example, loop values are split into several rows and the loop is run altogether seven times.

For loops are most useful and also clearest when they are used with list variables. This is illustrated by the example below, where @{ELEMENTS} contains an arbitrary long list of element names and Start Element is used with all of them.

Using several loop variables

It is also possible to use several loop variables. The syntax is the same as with the normal For loop, but all loop variables are listed in the cells between :FOR and IN. There can be any number of loop variables, but their number must match the number of loop values. The number of values must be evenly dividable by the number of variables.

This syntax naturally works both with and without list variables. In the former case, it is often possible to organize loop values below loop variables, as in the first part of the example below:

For in range

Earlier For loops always iterated over a sequence, and this is also the most common use case. Sometimes it is still convenient to have a For loop that is executed a certain number of times, and Robot Framework has a special FOR index IN RANGE limit syntax for this purpose. This syntax is derived from the similar Python idiom.

Similarly as other For loops, the For in range loop starts with :FOR and the loop variable is in the next cell. In this format there can be only one loop variable and it contains the current loop index. The next cell must contain IN RANGE and the subsequent cells loop limits.

In the simplest case, only the upper limit of the loop is specified. In this case, loop indexes start from zero and increase by one until, but excluding, the limit. It is also possible to give both the start and end limits. Then indexes start from the start limit, but increase similarly as in the simple case. Finally, it is possible to give also the step value that specifies the increment to use. If the step is negative, it is used as decrement. All these possibilities are illustrated by the examples below.

Different runner scripts

Test execution is normally started with the pybot or jybot commands. These commands are otherwise identical, but the former executes tests using the Python interpreter and the latter uses Jython. Which one to use depends on the needed test libraries. Some libraries use modules or syntax available only on Python, others use Java-based tools that require Jython, and some work on both. If you can use either pybot or jybot, the former is recommended, as Python is somewhat faster than Jython.

Another possibility for starting the test execution is running the runner.py script under the installed robot module directly. This method allows selecting the interpreter and setting command line options to it freely. The most common use case is altering the options controlling JVM maximum memory consumption.

Regardless of the runner script, a path (or paths) to the test data to be executed is given as an argument. Additionally, different command line options can be used to alter the test execution or generated outputs in some way.

Specifying the test data to be executed

Robot Framework test cases are created in files and directories, and they are executed by giving the path to the file or directory in question to the selected runner script. The path can be absolute or, more commonly, relative to the directory where tests are executed from. The given file or directory creates the top-level test suite, which gets its name, unless overridden with the --name option, from the file or directory name. Different execution possibilities are illustrated in the examples below. Note that in these examples, as well as in other examples in this section, only the pybot command is used, but jybot or a custom runner script could be used similarly.

pybot test_cases.html
pybot path/to/my_tests/
pybot /opt/robot/tests.html
pybot c:\robot\tests.html

It is also possible to give paths to several test case files or directories at once, separated with spaces. In this case, Robot Framework creates the top-level test suite automatically, and the specified files and directories become its child test suites. The name of the created test suite is got from child suite names by catenating them together with an ampersand (&) and spaces. For example, the name of the top-level suite in the first example below is My Tests & Your Tests. These automatically created names are seldom very good and they are often quite long. In most cases, it is thus better to use the --name option for overriding it, as in the second example below:

pybot my_tests.html your_tests.html
pybot --name Example path/to/tests/pattern_*.html

Using command line options

Robot Framework provides a number of command line options that can be used to control how test cases are executed and what outputs are generated. The syntax for using them is explained in this section. What options actually exist and how they can be used is discussed elsewhere in this chapter.

Generated outputs

The most visible output from test execution is the output displayed in the command line. All executed test suites and test cases, as well as their statuses, are shown there in real time. The example below shows the output from executing a simple test suite with only two test cases:

==============================================================================
Example test suite
==============================================================================
First test :: Possible documentation is here                          | PASS |
------------------------------------------------------------------------------
Second test                                                           | FAIL |
Error message is displayed here
==============================================================================
Example test suite                                                    | FAIL |
2 critical tests, 1 passed, 1 failed
2 tests total, 1 passed, 1 failed
==============================================================================
Output:  /path/to/output.xml
Report:  /path/to/report.html
Log:     /path/to/log.html

The command line output is very limited, and separate output files are normally needed for investigating the test execution. As the example above shows, three output files are generated by default. The first one is in the XML format and contains all the information about test execution. The second is a higher-level report and the third is a more detailed log file. These files and other possible output files are discussed in more detail in the section Different output files.

Return codes

Runner scripts communicate the overall test execution status to the system running them using return codes. The basic rule is that the return code is zero, which is a typical return code for success, when the execution starts successfully and no critical test fail. Possible return codes are explained in the table below.

Return codes should always be easily available after the execution, which makes it easy to automatically determine the overall execution status. For example, in bash shell the return code is in special variable $?, and in Windows it is in %ERRORLEVEL% variable. If you use some external tool for running tests, consult its documentation for how to get the return code.

Creating different reports and logs

You can use rebot for creating the same reports and logs that are created automatically during the test execution. Of course, it is not sensible to create the exactly same files, but, for example, having one report with all test cases and another with only some subset of tests can be useful. Another common usage is creating only the output file when running tests and generating logs and reports later. Tests can, for example, be executed on different environments, output files collected to a central place, and reports and logs created there. If generating reports and logs takes a lot of time when running tests on Jython, it is a good idea to try if using rebot, which always runs on Python, is any faster.

rebot output.xml
rebot path/to/output_file.xml
rebot --include smoke --name Smoke_Tests c:\results\output.xml

Combining outputs

The most important feature of rebot is its ability to combine outputs from different test execution rounds. This capability allows, for example, running the same test cases on different environments and generating an overall report from all outputs. Combining outputs is extremely easy, all that needs to be done is giving several output files as arguments:

rebot output1.xml output2.xml
rebot outputs/*.xml

When outputs are combined, a new top-level test suite is created so that test suites in the given output files are its child suites. This works the same way when multiple test data files or directories are executed, and also in this case the name of the top-level test suite is created by joining child suite names with an ampersand (&) and spaces. These automatically generated names are not that good, and it is often a good idea to use --name to give a more meaningful name:

rebot --name Browser_Compatibility firefox.xml opera.xml safari.xml ie.xml
rebot --include smoke --name Smoke_Tests c:\results\*.xml

Escaping options

In Robot Framework's command line escaping mechanism, problematic characters are escaped with freely selected text. The command line option to use is --escape (short version -E), which takes an argument in the format what:with, where what is the name of the character to escape and with is the string to escape it with. Characters that can be escaped are listed in the table below:

The following examples make the syntax more clear. In the first example, the metadata X gets the value Value with spaces, and in the second variable ${VAR} is assigned to "Hello, world!".

--escape space:_ --metadata X:Value_with_spaces
-E space:SP -E quot:QU -E comma:CO -E exclam:EX -v VAR:QUHelloCOSPworldEXQU

Note that all the given command line arguments, including paths to test data, are escaped. Escape character sequences thus need to be selected carefully.

Using argument files

Another possibility to handle complicated arguments is placing them into a argument file and using --argumentfile (short option -A) to specify the path to it, along with possible other options. These files can contain both command line options and paths to the test data, one per line. Argument files can contain any ASCII characters without escaping, but spaces in the beginning and end of lines are ignored. Additionally, empty lines and lines starting with a hash mark (#) are ignored.

An example argument file:

--doc This is an example (where "special characters" are ok!)
--metadata X:Value with spaces
--variable VAR:Hello, world!
# This is a comment line
path/to/test directory/

When an argument file is used on the command line, its contents are placed to the original list of arguments to the same place where the argument file option was. Argument files can be used either alone so that they contain all the options and paths to the test data, or along with other options and paths:

pybot --argumentfile all_arguments.txt
pybot --name example --argumentfile other_options_and_paths.txt
pybot --argumentfile default_options.txt --name example my_tests.html

By test suite and test case names

Test suites and test cases can be selected by their names with the command line options --suite (-s) and --test (-t), respectively. Both of these options can be used several times to select several test suites or cases. Arguments to these options are case- and space-insensitive, and there can also be simple patterns matching multiple names. If both the --suite and --test options are used, only test cases in matching suites with matching names are selected.

--test Example
--test mytest --test yourtest
--test example*
--suite example-??
--suite mysuite --test mytest --test your*

Using the --suite option is more or less the same as executing only the appropriate test case file or directory. One major benefit is the possibility to select the suite based on its parent suite. The syntax for this is specifying both the parent and child suite names separated with a dot. In this case, the possible setup and teardown of the parent suite are executed.

--suite parent.child
--suite myhouse.myhousemusic --test jack*

Selecting individual test cases with the --test option is very practical when creating test cases, but quite limited when running tests automatically. The --suite option can be useful in that case, but in general, selecting test cases by tag names is more flexible.

By tag names

It is possible to include and exclude test cases by tag names with the --include (-i) and --exclude (-e) options, respectively. When the former is used, only test cases having a matching tag are selected, and with the latter, test cases having a matching tag are not. If both are used, only tests with a tag matching the former option, and not with a tag matching the latter, are selected.

--include example
--exclude not_ready
--include regression --exclude long_lasting

Both --include and --exclude can be used several times to match multiple tags, and their arguments can be simple patterns. In these cases, the rules for selecting test cases apply, so that test cases with a tag matching any include patterns are selected, and tests with a tag matching exclude patterns are not. It is also possible to select only test cases that have two or more specified tags by separating the tags either with & or AND (case-sensitive). Similarly, only tests with a certain tag, but without some others, can be selected by separating these tags with NOT (case-sensitive).

--include req-*
--include regressionANDiter-42
--include tag1&tag2&tag3&tag4
--exclude regressionNOTowner-*

Selecting test cases by tags is a very flexible mechanism and allows many interesting possibilities:

• A subset of tests to be executed before other tests can be tagged with smoke and executed with --include smoke.
• Unfinished test can be committed to version control with the tag not_ready and excluded from the test execution with --exclude not_ready.
• Tests can be tagged with iter-<num>, where <num> specifies the number of the current iteration, and after executing all test cases, a separate report containing only the tests for a certain iteration can be generated (for example, rebot --include iter-42 ouput.xml).

Setting the name

When Robot Framework parses test data, test suite names are created from file and directory names. The name of the top-level test suite can, however, be overridden with the command line option --name (-N). Underscores in the given name are converted to spaces automatically, and words in the name capitalized.

Setting the documentation

In addition to defining documentation in the test data, documentation of the top-level suite can be given from the command line with the option --doc (-D). Underscores in the given documentation are converted to spaces, and it may contain simple HTML formatting.

Setting free metadata

Free test suite metadata may also be given from the command line with the option --metadata (-M). The argument must be in the format name:value, where name the name of the metadata to set and value is its value. Underscores in the former are converted to spaces and words capitalized, and the latter may contain simple HTML formatting. This option may be used several times to set multiple metadata.

Setting tags

The command line option --settag (-G) can be used to set the given tag to all executed test cases. This option may be used several times to set multiple tags.

Locations automatically in PYTHONPATH

Python and Jython installations put their own library directories into PYTHONPATH automatically. This means that test libraries packaged using Python's own packaging system are automatically installed into a location that is in the library search path. Robot Framework also puts the directory containing its standard libraries and the directory where tests are executed from into PYTHONPATH.

Setting PYTHONPATH in system

There are several ways to alter PYTHONPATH in the system, but the most common one is setting an environment variable with the same name before the test execution. Jython actually does not use PYTHONPATH environment variable normally, but Robot Framework ensures that locations listed in it are added into the library search path regardless the interpreter.

Setting CLASSPATH in the system

CLASSPATH is used only with Jython, and the most common way to alter it is setting an environment variable similarly as with PYTHONPATH. Note that instead of CLASSPATH, it is always possible to use PYTHONPATH with Jython, even with libraries and listeners implemented with Java.

Using the --pythonpath option

Robot Framework also has a separate command line option --pythonpath (-P) for adding directories or archives into PYTHONPATH. Multiple paths can be given by separating them with a colon (:) or using this option several times. The given path can also be a glob pattern matching multiple paths, but then it normally must be escaped.

Examples:

--pythonpath libs/
--pythonpath /opt/testlibs:mylibs.zip:yourlibs
--pythonpath mylib.jar --pythonpath lib/STAR.jar --escape star:STAR

Output directory

All output files can be set using an absolute path, in which case they are created to the specified place, but in other cases, the path is considered relative to the output directory. The default output directory is the directory where the execution is started from, but it can be altered with the --outputdir (-d) option. The path set with this option is, again, relative to the execution directory, but can naturally be given also as an absolute path. Regardless of how a path to an individual output file is obtained, its parent directory is created automatically, if it does not exist already.

Output file

Output files contain all the test execution results in the XML format. Log, report, and summary files are generated based on output files, and output files can also be combined and otherwise post-processed after the test execution.

The command line option --output (-o) determines where output files are created. Output files are always created when tests are executed, and the default name for them is output.xml. When post-processing outputs, new output files are not created unless this option is explicitly used.

Log file

Log files contain details about the executed test cases in HTML format. They have a hierarchical structure showing test suite, test case and keyword details. Log files are needed nearly every time when test results are to be investigated in detail. Even though log files also have statistics, report and summary files are better for getting an higher-level overview.

The command line option --log (-l) determines where log files are created. Unless the special value NONE is used, log files are always created and their default name is log.html.

An example of beginning of log file

An example of log file with keyword details visible

Report file

Report files contain an overview of the test execution results in HTML format. They have statistics based on tags and executed test suites, as well as a list of all executed test cases. When both reports and logs are generated, the report has links to the log file for easy navigation to more detailed information. It is easy to see the overall test execution status from reports, because their background color is green, if all critical tests pass, and bright red otherwise.

The command line option --report (-r) determines where report files are created. Similarly as log files, reports are always created unless NONE is used as a value, and their default name is report.html.

An example report file of successful test execution

An example report file of failed test execution

Summary file

Summary files contain the same statistics as reports, and their background color is similarly green or red, depending on the overall test execution status. However, they have no test case details, which makes them much smaller. They are useful when a large number of test cases is executed and a very high-level overview is needed.

Summary files are not generated by default. When they are needed, they can be created using the command line option --summary (-S).

An example summary file

Debug file

Debug files are plain text files that are written during the test execution. All messages got from test libraries are written to them, as well as information about started and ended test suites, test cases and keywords. Debug files can be used for monitoring the test execution. This can be done using, for example, a separate file viewer tool, or in UNIX-like systems, simply with the tail -f command.

Debug files are not created unless the command line option --debugfile (-b) is used explicitly.

Timestamping output files

All output files listed in this section can be automatically timestamped with the option --timestampoutputs (-T), which is one of the rare options taking no value. When this option is used, a timestamp in the format YYYYMMDD-hhmmss is placed between the extension and the basename of each file. The example below would, for example, create such output files as output-20080604-163225.xml and mylog-20080604-163225.html.

pybot --timestampoutputs --log mylog.html --report NONE tests.html

Setting titles

The default titles for log, report and summary files are generated by prefixing the name of the top-level test suite with Test Log, Test Report or Summary Report. Custom titles can be given from the command line using the options --logtitle, --reporttitle and --summarytitle, respectively. With all these options, underscores in the given title are converted to spaces automatically.

Examples:

pybot --logtitle Smoke_Test_Log --reporttitle Smoke_Test_Report --include smoke mytests
rebot --summarytitle Overview --summary overview.html --log none --report none *.xml

Available log levels

Messages in log files can have different log levels. Some of the messages are written by Robot Framework itself, but also executed keywords can log information using different levels. The available log levels are:

FAIL

Used when a keyword fails. Can be used only by Robot Framework.

WARN

Used to display warnings. Note that warnings do not change the test case status, so they can easily be missed.

INFO

The default level for normal messages. By default, messages below this level are not shown in the log file.

DEBUG

Used for debugging purposes. Useful for example for logging what libraries are doing internally.

TRACE

Another debugging level. Robot Framework itself logs the actual values of keyword arguments and the return values using this level.

Setting log level

By default, log messages below INFO are not logged, but this threshold level can be changed from the command line using the --loglevel (-L) option. This option takes any of the available log levels as an argument, and that level becomes the new threshold level. A special value NONE can also be used to disable logging altogether.

Another possibility to change the log level is using the BuiltIn keyword Set Log Level in the test data. It takes the same arguments as the --loglevel option, and it also returns the old level so that it can be restored later, for example, in a test teardown.

Benefits

When executing a large number of test cases, the size of log files can increase to the extent that opening them into browsers is slow. Additionally, since log files can be created only after output files are ready, they are available only after the test execution. This is not a problem if the test execution time is short, but with long-running tests it is better to be able to investigate the first failures while the rest of the tests are still running.

Splitting outputs provides a solution for both of these problems. First of all, splitting logs means that individual log files are smaller and thus faster to open. If outputs are split while executing test cases, the lower-level log files are also created immediateay when the equivelent output files are ready. Notifications about created files can be received through the listener interface, and automatic variables ${LOG_FILE} and ${OUTPUT_FILE} always contain the path to the current file.

Specifying a split level

Outputs are split from a certain test suite level. Suites below this level will get their own outputs, and everything above the level will be in an index file, which has links to lower-level files. Only output files and log files are split, and they are always split from the same level. Splitting outputs gives the best results when test cases are organized into a relatively balanced hierarchical structure.

Splitting can be activated with the command line option --splitoutputs, which takes the split level as an argument. Index files have the same name as the output and log would have without splitting, and lower-level files get a running counter between the basename and extension.

Examples

Explaining how splitting outputs actually works is easiest with examples, and it is also a good idea to experiment with real test data. In these examples we assume that test cases are organized into test suites hierarchically in the following way:

project
|-- component_a
|   |-- feature_a1
|   |   |-- a11.html
|   |   `-- a12.html
|   `-- feature_a2
|       `-- a21.html
|-- component_b
|   `-- feature_b1
|       |-- b11.html
|       `-- b21.html
`-- component_c
    |-- c1.html
    |-- c2.html
    `-- c3.html

In the first example these test cases are executed so that they are split right below the top-level test suite. The command line to use is as follows, and the following table lists all the created output files:

pybot --splitoutputs 1 project

The fact that output files are split is transparent when post-processing outputs afterwards, and it is enough to point rebot to the index file. Splitting works with rebot regardless of whether outputs are split earlier or not. Outputs created by the first example could thus by re-split, for example, as:

rebot --splitoutputs 2 output.xml

In this example, splitting is done from the second level. The table below again lists created the files, and because rebot does not create new output files by default, they are not listed in the table either.

The last example splits outputs from the third level. It also shows how to configure output file names when splitting:

rebot --splitoutputs 3 --log mylog.html --report none output.xml

If a split level higher than three is used with this test data, all the information ends up to index files. The end result is thus exactly the same as if outputs were not split at all.

Configuring displayed suite statistics

When a deeper suite structure is executed, showing all the test suite levels in the Statistics by Suite table may make the table somewhat difficult to read. You can control the number of levels displayed with the command line option --suitestatlevel. It takes the required level as an integer, and if 0 is used, the whole table is removed.

Including and excluding tag statistics

When many tags are used, the Statistics by Tag table can become quite congested. If this happens, the command line options --tagstatinclude and --tagstatexclude can be used to select which tags to display, similarly as --include and --exclude are used to select test cases:

--tagstatinclude some-tag --tagstatinclude another-tag
--tagstatexclude owner-*
--tagstatinclude prefix-* --tagstatexclude prefix-13

These settings affect also the Test Details by Tag table, so that it has details only by the selected tags. This can make the report considerably smaller, which is why excluding tags that are not interesting can be recommended.

Generating combined tag statistics

The command line option --tagstatcombine can be used to generate aggregate tags that combine statistics from multiple tags. These new combined tags are shown in the Statistics by Tag table, and the matching tests are listed in the Test Details by Tag table. There are three somewhat different ways for giving arguments for this option:

One tag as a simple pattern

All tags matching the given pattern are combined together.

Two or more tags separated by AND or &

The combined statistics contain tests that have all the listed tags. Tags can be given as simple patterns.

Two or more tags separated by NOT

The combined statistics contain tests that have the first tag but not the others. Also in this case tags may be patterns.

The following examples illustrate these usages, and the figure below shows a snippet of the resulting Statistics by Tag table when the example test data is executed with these options:

--tagstatcombine owner-*
--tagstatcombine smokeANDmytag
--tagstatcombine smokeNOTowner-janne*

Examples of combined tag statistics

Creating links from tag names

You can add external links to the Statistics by Tag table by using the command line option --tagstatlink. Arguments to this option are given in the format tag:link:name, where tag specifies the tags to assign the link to, link is the link to be created, and name is the name to give to the link.

tag may be a single tag, but more commonly a simple pattern where * matches anything and ? matches any single character. When tag is a pattern, the matches to wildcards may be used in link with the syntax %N, where "N" is the index of the match starting from 1.

The following examples illustrate the usage of this option, and the figure below shows a snippet of the resulting Statistics by Tag table when example test data is executed with these options:

--tagstatlink mytag:http://www.google.com:Google
--tagstatlink jython-bug-*:http://bugs.jython.org/issue_%1:Jython-bugs
--tagstatlink owner-*:mailto:%1@domain.com?subject=Acceptance_Tests:Send_Mail

Examples of links from tag names

Adding documentation to tags

Tags can be given a documentation with the command line option --tagdoc, which takes an argument in the format tag:doc. "tag" is the name of the tag to assign the documentation to, and it can also be a simple pattern matching multiple tags. "doc" is the assigned documentation. Underscores in it are converted to spaces automatically, and it can also contain HTML formatting. The given documentation is shown with matching tags in the Test Details by Tag table, and as a tool tip for these tags in the Statistics by Tag table.

Examples:

--tagdoc mytag:My_documentation
--tagdoc regression:*See*_http://info.html
--tagdoc owner-*:Original_author

Setting times for combined outputs

When combining outputs, it is possible to set the start and end time of the combined test suite using the options --starttime and --endtime, respectively. This is convenient, because by default, combined suites do not have these values. When both the start and end time are given, the elapsed time is also calculated based on them. Otherwise the elapsed time is got by adding the elapsed times of the child test suites together.

Times must be given as timestamps in the format YYYY-MM-DD hh:mm:ss.mil, where all separators are optional and the parts from milliseconds to hours can be omitted. For example, 2008-06-11 17:59:20.495 is equivalent both to 20080611-175920.495 and 20080611175920495, and also mere 20080611 would work.

Examples:

rebot --starttime 20080611-17:59:20.495 output1.xml output2.xml
rebot --starttime 20080611-175920 --endtime 20080611-180242 *.xml

Removing keywords from outputs

Most of the content of output files comes from keywords and especially their log messages. When creating higher level reports, log files are not necessarily needed at all, and then keywords and their messages just take space unnecessarily. In these situations, the command line option --removekeywords can be used to dispose of unnecessary keywords. It has two possible values:

ALL

All keywords are unconditionally removed.

PASSED

Keywords are removed only from the passed test cases. In most cases, log files created after this contain enough information to investigate possible failures.

Removing keywords makes output files considerably smaller and thus faster to process further. Even when keywords are removed, names, arguments and statuses of top-level keywords are preserved, so it is still possible to create log files and see the high-level structure of each test case.

Supported programming languages

Robot Framework itself is written with Python, so naturally, test libraries extending it can be implemented using the same language. Additionally, it is possible to write libraries using Java, which requires running the framework on the Jython interpreter. Pure Python code works both on Python and Jython interpreters, assuming that it does not use syntax or libraries that are not available on Jython.

It is also possible to implement a test library with C by using Python C API. Another, and in most cases easier, method to interact with C code from a library is using Python's ctypes module.

Finally, it is possible to implement the actual test library functionality using any language and call that from a thin Python or Java wrapper library. Possible approaches include calling external scripts or tools through the operating system or using XML-RPC to connect the wrapper with the real implementation. The former approach is quite widely used and there is a proof-of-concept prototype also for the latter. The plan is to have XML-RPC support built in to Robot Framework in the future.

Different test library APIs

Robot Framework has three different test library APIs.

Static API

The simplest approach is having a module (in Python) or a class (in Python or Java) with methods the names of which map more or less directly to keyword names. Keywords also take the same arguments as the code implementing them. Keywords report failures with exceptions, log by writing to standard output and can return values using the return statement.

Dynamic API

Dynamic libraries are classes that implement a method to get the names of the keywords they implement, and another method to execute a named keyword with given arguments. The names of the keywords to implement, as well as how they are executed, can be determined dynamically at runtime, but reporting the status, logging and returning values is done similarly as in the static API.

Hybrid API

This is a hybrid between the static and the dynamic API. Libraries are classes with a method telling what keywords they implement, but those keywords must be available directly. Everything else except discovering what keywords are implemented is similar as in the static API.

All these APIs are described in this chapter. Everything is based on how the static API works, so its functions are discussed first. How the dynamic library API and the hybrid library API differ from it is then discussed in sections of their own.

The examples in this chapter are mainly about using Python, but they should be easy to understand also for Java-only developers. In those few cases where APIs have differences, both usages are explained with adequate examples.

Test library names

The name of a test library that is used when a library is imported is the same as the name of the module or class implementing it. For example, if you have a Python module MyLibrary (that is, the file MyLibrary.py), it will create a library with a name MyLibrary. Similarly, a Java class YourLibrary, when it is not in any package, creates a library with exactly that name.

Python classes are always inside a module. If the name of a class implementing a library is the same as the name of the module, Robot Framework allows dropping the module name when importing the library. For example, the class MyLib in the MyLib.py file can be used as a library with the name MyLib. If the module name and class name are different, libraries must be taken into use using both module and class names, such as mymodule.MyLibrary.

Java classes in a non-default package must be taken into use with the full name. For example, the class MyLib in the com.mycompany.myproject package must be imported with the name com.mycompany.myproject.MyLib.

Providing arguments to test libraries

All test libraries implemented as classes can take arguments. These arguments are specified in the Setting table after the library name, and when Robot Framework creates an instance of the imported library, it passes them to its constructor. Libraries implemented as a module cannot take any arguments, so trying to use those results in an error.

The number of arguments needed by the library is the same as the number of arguments accepted by the library's constructor. The default values and variable number of arguments work similarly as with keyword arguments, with the exception that there is no variable argument support for Java libraries. Arguments passed to the library, as well as the library name itself, can be specified using variables, so it is possible to alter them, for example, from the command line.

Example implementations, first one in Python and second in Java, for the libraries used in the above example:

from example import Connection

class MyLibrary:

    def __init__(self, host, port=80):
        self._conn = Connection(host, int(port))

    def send_message(self, message):
        self._conn.send(message)

public class AnotherLib {

    private String setting = null;

    public AnotherLib(String setting) {
        setting = setting;
    }

    public void doSomething() {
        if setting.equals("42") {
            // do something ...
        }
    }
}

Test library scope

Libraries implemented as classes can have an internal state, which can be altered by keywords and with arguments to the constructor of the library. Because the state can affect how keywords actually behave, it is important to make sure that changes in one test case do not accidentally affect other test cases. This kind of dependencies may create hard-to-debug problems, for example, when new test cases are added and they use the library inconsistently.

Robot Framework attempts to keep test cases independent from each other: by default, it creates new instances of test libraries for every test case. However, this behavior is not always desirable, because sometimes test cases should be able to share a common state. Additionally, all libraries do not have a state and creating new instances of them is simply not needed.

Test libraries can control when new libraries are created with a class attribute ROBOT_LIBRARY_SCOPE . This attribute must be a string and it can have the following three values:

TEST CASE

A new instance is created for every test case. A possible suite setup and suite teardown share yet another instance. This is the default.

TEST SUITE

A new instance is created for every test suite. The lowest-level test suites, created from test case files and containing test cases, have instances of their own, and higher-level suites all get their own instances for their possible setups and teardowns.

GLOBAL

Only one instance is created during the whole test execution and it is shared by all test cases and test suites. Libraries created from modules are always global.

When the TEST SUITE or GLOBAL scopes are used with test libraries that have a state, it is recommended that libraries have some special keyword for cleaning up the state. This keyword can then be used, for example, in a suite setup or teardown to ensure that test cases in the next test suites can start from a known state. For example, SeleniumLibrary uses the GLOBAL scope to enable using the same browser in different test cases without having to reopen it, and it also has the Close All Browsers keyword for easily closing all open browsers.

Example Python library using the TEST SUITE scope:

class ExampleLibrary:

    ROBOT_LIBRARY_SCOPE = 'TEST SUITE'

    def __init__(self):
        self._counter = 0

    def count(self):
        self._counter += 1
        print self._counter

    def clear_counter(self):
        self._counter = 0

Example Java library using the GLOBAL scope:

public class ExampleLibrary {

    public static String ROBOT_LIBRARY_SCOPE = "GLOBAL";

    private int counter = 0;

    public void count() {
        counter += 1;
        System.out.println(counter);
    }

    public void clearCounter() {
        counter = 0;
    }
}

Keyword names

When the static library API is used, Robot Framework uses reflection to find out what methods the library implements. With dynamic library API and hybrid library API, keyword names are got from the library directly. Naturally, Robot Framework can see only the public methods and it also excludes all methods starting with an underscore. With Java libraries, also methods that are implemented in java.lang.Object and not overridden are ignored.

Keyword names used in the test data are compared with method names to find the method implementing these keywords. Name comparison is case-insensitive, and also spaces and underscores are ignored. For example, the method hello maps to the keyword name Hello, hello or even h e l l o. Similarly both the do_nothing and doNothing methods can be used as the Do Nothing keyword in the test data.

Example Python library implemented as a module in the MyLibrary.py file:

def hello(name):
    print "Hello, %s!" % name

def do_nothing():
    pass

Example Java library implemented as a class in the MyLibrary.java file:

public class MyLibrary {

    public void hello(String name) {
        System.out.println("Hello, " + name + "!");
    }

    public void doNothing() {
    }

}

The example below illustrates how the example libraries above can be used. If you want to try this yourself, make sure that the library is in the library search path. Note that in the subsequent examples all boilerplates, such as taking a library into use and creating a test case, is excluded.

Keyword arguments

With a static and hybrid API, the information on how many arguments a keyword needs is got directly from the method that implements it. Libraries using the dynamic library API have other means for getting this information, so this section is not relevant to them.

The most common and also simplest situation is when a keyword needs an exact number of arguments. In this case, both the Python and Java methods simply take exactly those arguments. For example, a method implementing a keyword with no arguments takes no arguments either, a method implementing a keyword with one argument also takes one argument, and so on.

Example Python keywords taking different numbers of arguments:

def no_arguments():
    print "Keyword got no arguments"

def one_argument(arg):
    print "Keyword got one argument '%s'" % arg

def multiple_arguments(a1, a2, a3):
    print "Keyword got three arguments '%s', '%s' and '%s'" % (a1, a2, a3)

def one_default(arg='default'):
    print "Argument has value '%s'" % arg

def multiple_defaults(arg1, arg2='default 1', arg3='default 2'):
    print "Got arguments %s, %s and %s" % (arg1, arg2, arg3)

public void oneDefault(String arg) {
    System.out.println("Argument has value '" + arg "'");
}

public void oneDefault() {
    oneDefault("default");
}

public void multipleDefaults(String arg1, String arg2, String arg3) {
    System.out.println("Got arguments " + arg1 + ", " + arg2 + " and " + arg3);
}

public void multipleDefaults(String arg1, String arg2) {
    multipleDefaults(arg1, arg2, "default 2");
}

public void multipleDefaults(String arg1) {
    multipleDefaults(arg1, "default 1");
}

def any_arguments(*args):
    print "Got arguments:"
    for arg in args:
        print arg

def one_required(required, *others):
    print "Required: %s\nOthers:" % required
    for arg in others:
        print arg

def also_defaults(req, def1="default 1", def2="default 2", *rest):
    print req, def1, def2, rest

public void anyArguments(String[] args) {
    System.out.println("Got arguments:");
    for (int i; i < args.length; i++) {
        System.out.println(args[i]);
    }
}

public void oneRequired(String required, String[] others) {
    System.out.println("Required: " + required + "\nOthers:");
    for (int i; i < others.length; i++) {
        System.out.println(others[i]);
    }
}

Reporting keyword status

Reporting keyword status is done simply using exceptions. If a method raises an exception, the keyword status is FAIL, and if it returns normally, the status is PASS.

The error message shown in logs, reports and the console is created from the exception type and its message. With generic exceptions (for example, AssertionError, Exception, and RuntimeError), only the exception message is used, and with others, the message is created in the format ExceptionType: Actual message. In both cases, it is important for the users that the exception message is as informative as possible.

If the error message is longer than 20 lines, it will be automatically cut from the middle to prevent reports from getting too long and difficult to read. The full error message is always shown in the log message of the failed keyword, so it is not lost even if this happens.

Logging information

Exception messages are not the only way to give information to the users. In addition to that, methods can also send messages to log files simply by writing to standard output (stdout) or standard error (stderr), and they can even use different log levels.

By default, everything written by a method to stdout is written into a log file as a single entry with the log level INFO. Messages written into stderr are handled similarly otherwise, but they are echoed back to the original stderr after the keyword execution has finished.

To use other log levels than INFO, or to create several messages, specify the log level explicitly by embedding the level into the message in the format *LEVEL* Actual log message, where *LEVEL* must be in the beginning of a line and LEVEL is one of the available logging levels TRACE, DEBUG, INFO and WARN.

Everything normally logged by the library will be converted into a format that can be safely represented as HTML. For example, <b>foo</b> will be displayed in the log exactly like that and not as foo. If libraries want to use formatting, links, display images and so on, they can use a special pseudo log level HTML. Robot Framework will write these messages directly into the log with the INFO level, so they can use any HTML syntax they want. However, this feature needs to be used with care, because one badly placed </table> tag can ruin the log file quite badly.

The following examples clarify how logging with different levels works. Java programmers should regard the code print 'message' as pseudocode meaning System.out.println("message");.

print 'Hello from a library.'
print '*WARN* Warning from a library.'
print '*INFO* Hello again!'
print 'This will be part of the previous message.'
print '*INFO* This is a new message.'
print '*INFO* This is <b>normal text</b>.'
print '*HTML* This is <b>bold</b>.'
print '*HTML* <a href="http://robotframework.org">Robot Framework</a>'

In most cases, the INFO level is adequate. The levels below it, DEBUG and TRACE, are useful for writing debug information. These messages are normally not shown, but they can facilitate debugging possible problems in the library itself. The WARN level can be used to make messages slightly more visible.

Returning values

The final way for keywords to communicate back to the core framework is returning information retrieved from the system under test or generated by some other means. The returned values can be assigned to variables in the test data and then used as inputs for other keywords, even from different test libraries.

Values are returned using the return statement both from the Python and Java methods. Normally, one value is assigned into one scalar variable, as illustrated in the example below. This example also illustrates that it is possible to return any objects and to use extended variable syntax to access object attributes.

from mymodule import MyObject

def return_string():
    return "Hello, world!"

def return_object(name):
    return MyObject(name)

Keywords can also return values so that they can be assigned into several scalar variables at once, into a list variable, or into scalar variables and a list variable. All these usages require that returned values are Python lists or tuples or, since Robot 1.8.6, Java arrays. If there is a need, support for other iterables can be added in the future.

def return_two_values():
    return 'first value', 'second value'

def return_multiple_values():
    return ['a', 'list', 'of', 'strings']

Documenting libraries

A test library without documentation about what keywords it contains and what those keywords do is rather useless. To ease maintenance, it is highly recommended that library documentation is included in the source code and generated from it. Basically, that means using docstrings with Python and Javadoc with Java, as in the examples below.

class MyLibrary:
    """This is an example library with some documentation."""

    def keyword_with_short_documentation(self, argument):
        """This keyword has only a short documentation"""
        pass

    def keyword_with_longer_documentation(self):
        """First line of the documentation is here.

        Longer documentation continues here and it can contain
        multiple lines or paragraphs.
        """
        pass

/**
 *  This is an example library with some documentation.
 */
public class MyLibrary {

    /**
     * This keyword has only a short documentation
     */
    public void keywordWithShortDocumentation(String argument) {
    }

    /**
     * First line of the documentation is here.
     *
     * Longer documentation continues here and it can contain
     * multiple lines or paragraphs.
     */
    public void keywordWithLongerDocumentation() {
    }

}

Both Python and Java have tools for creating an API documentation of a library documented as above. However, outputs from these tools can be slightly technical for some users. Another alternative is using Robot Framework's own documentation tool libdoc.py. This tool can create a library documentation from both Python and Java libraries using the static library API, such as the ones above, but it also handles libraries using the dynamic library API and hybrid library API.

The first line of a keyword documentation is used for a special purpose and should contain a short overall description of the keyword. It is used as a short documentation, for example as a tool tip, by libdoc.py and also shown in the test logs. However, the latter does not work with Java libraries using the static API, because their documentations are lost in compilation and not available at runtime.

Testing libraries

Any non-trivial test library needs to be thoroughly tested to prevent bugs in them. Of course, this testing should be automated to make it easy to rerun tests when libraries are changed.

Both Python and Java have excellent unit testing tools, and they suite very well for testing libraries. There are no major differences in using them for this purpose compared to using them for some other testing. The developers familiar with these tools do not need to learn anything new, and the developers not familiar with them should learn them anyway.

It is also easy to use Robot Framework itself for testing libraries and that way have actual end-to-end acceptance tests for them. There are plenty of useful keywords in the BuiltIn library for this purpose. One worth mentioning specifically is Run Keyword And Expect Error, which is useful for testing that keywords report errors correctly.

Whether to use a unit- or acceptance-level testing approach depends on the context. If there is a need to simulate the actual system under test, it is often easier on the unit level. On the other hand, acceptance tests ensure that keywords do work through Robot Framework. If you cannot decide, of course it is possible to use both the approaches.

Packaging libraries

After a library is implemented, documented, and tested, it still needs to be distributed to the users. With simple libraries consisting of a single file, it is often enough to ask the users to copy that file somewhere and set the library search path accordingly. With more complicated libraries, package them to make the installation easier.

Since libraries are normal programming code, they can be packaged using normal packaging tools. With Python, good options include distutils, contained by Python's standard library, and the newer setuptools. A benefit of these tools is that library modules are installed into a location that is automatically in the library search path.

When using Java, it is natural to package libraries into a JAR archive. The JAR package must be put into the library search path before running tests, but it is easy to create a start-up script that does that automatically.

Getting keyword names

Dynamic libraries tell what keywords they implement with the get_keyword_names method. The method also has the alias getKeywordNames that is recommended when writing Java. This method cannot take any arguments, and it must return a list of strings (in Python) or a string array (in Java) containing the names of the keywords that the library implements.

If the returned keyword names contain several words, they can be returned separated with spaces or underscores, or in the camelCase format. For example, ['first keyword', 'second keyword'], ['first_keyword', 'second_keyword'], and ['firstKeyword', 'secondKeyword'] would all result in the keywords First Keyword and Second Keyword.

Dynamic libraries must always have this method. If it is missing, or if calling it fails for some reason, the library is considered a static library, instead.

Running keywords

Dynamic libraries have a special run_keyword (alias runKeyword) method for executing their keywords. When a keyword from a dynamic library is used in the test data, Robot Framework uses the library's run_keyword method to get it executed. This method takes two arguments. The first argument is a string containing the name of the keyword to be executed in the same format as returned by get_keword_names. The second argument is a list of arguments (an object array in Java) given to the keyword in the test data.

After the library has got the keyword name and arguments, it can execute the keyword freely, but it must use the same mechanism to communicate with the framework as static libraries. This means using exceptions for reporting keyword status, logging by writing to the standard output and using the return statement in run_keyword for returning something.

Every dynamic library must have both the get_keyword_names and run_keyword methods. The rest of the methods in the dynamic API are optional, so the example below shows a working (albeit trivial) dynamic library.

class DynamicExample:

    def get_keyword_names(self):
        return ['first keyword', 'second keyword']

    def run_keyword(self, name, args):
        print "Running keyword %s with arguments %s" % (name, args)

Getting keyword arguments

If a dynamic library only implements the get_keyword_names and run_keyword methods, Robot Framework does not have any information about the arguments that the implemented keywords need. For example, both First Keyword and Second Keyword in the example above could be used with any number of arguments. This is problematic, because most real keywords expect a certain number of keywords, and under these circumstances they would need to check the argument counts themselves.

Starting from Robot Framework version 1.8.4, dynamic libraries can tell Robot Framework what arguments the keywords that it implements actually expect. This is done with the get_keyword_arguments (alias getKeywordArguments) method, which takes the name of a keyword as an argument and returns a list of strings (a string array in Java) containing the arguments accepted by that keyword.

Similarly as static keywords, dynamic keywords can require any number of arguments, have default values and accept a variable number of arguments. The syntax for how to represent all these different situations is explained in the following table. Note that the examples use Python lists of strings, but Java developers should be able to translate them to string arrays.

When the get_keyword_arguments is used, Robot Framework automatically calculates how many arguments the keywords require. If a keyword is used with an invalid number of arguments, an error occurs and run_keyword is not even called. The last column of the table above shows the minimum and maximum argument counts calculated from the presented examples.

The actual argument names do not matter when tests are executed, because only argument counts are of concern to Robot Framework. On the other hand, if the libdoc.py tool is used for documenting the library, arguments are shown in the documentation, in which case they need to have meaningful names.

Getting keyword documentation

The final special method that dynamic libraries can implement is get_keyword_documentation (alias getKeywordDocumentation). It takes a keyword name as an argument and, as the method name implies, returns its documentation as a string. This method also only works starting from Robot Framework version 1.8.4.

The returned documentation is used similarly as the keyword documentation string with static libraries implemented with Python. The main use case is getting keywords' documentations into a library documentation generated with libdoc.py. Additionally, the first line of the documentation (until the first \n) is shown in test logs.

Summary

All special methods in the dynamic API are listed in the table below. Method names are listed in the underscore format, but their camelCase aliases function in exactly the same way.

It is possible to write a formal interface specification in Java, as below. However, remember that libraries do not need to implement any explicit interface, because Robot Framework directly checks if the library has the required get_keyword_names and run_keyword methods. Additionally, get_keyword_arguments and get_keyword_documentation are completely optional.

public interface RobotFrameworkDynamicAPI {

    String[] getKeywordNames();

    Object runKeyword(String name, Object[] arguments);

    String[] getKeywordArguments(String name);

    String getKeywordDocumentation(String name);

}

Getting keyword names