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diff --git a/testing/marionette/client/docs/basics.rst b/testing/marionette/client/docs/basics.rst new file mode 100644 index 000000000..0de72c625 --- /dev/null +++ b/testing/marionette/client/docs/basics.rst @@ -0,0 +1,185 @@ +.. py:currentmodule:: marionette_driver.marionette + +Marionette Python Client +======================== + +The Marionette Python client library allows you to remotely control a +Gecko-based browser or device which is running a Marionette_ +server. This includes Firefox Desktop and Firefox for Android. + +The Marionette server is built directly into Gecko and can be started by +passing in a command line option to Gecko, or by using a Marionette-enabled +build. The server listens for connections from various clients. Clients can +then control Gecko by sending commands to the server. + +This is the official Python client for Marionette. There also exists a +`NodeJS client`_ maintained by the Firefox OS automation team. + +.. _Marionette: https://developer.mozilla.org/en-US/docs/Marionette +.. _NodeJS client: https://github.com/mozilla-b2g/gaia/tree/master/tests/jsmarionette + +Getting the Client +------------------ + +The Python client is officially supported. To install it, first make sure you +have `pip installed`_ then run: + +.. parsed-literal:: + pip install marionette_driver + +It's highly recommended to use virtualenv_ when installing Marionette to avoid +package conflicts and other general nastiness. + +You should now be ready to start using Marionette. The best way to learn is to +play around with it. Start a `Marionette-enabled instance of Firefox`_, fire up +a python shell and follow along with the +:doc:`interactive tutorial <interactive>`! + +.. _pip installed: https://pip.pypa.io/en/latest/installing.html +.. _virtualenv: http://virtualenv.readthedocs.org/en/latest/ +.. _Marionette-enabled instance of Firefox: https://developer.mozilla.org/en-US/docs/Mozilla/QA/Marionette/Builds + +Using the Client for Testing +---------------------------- + +Please visit the `Marionette Tests`_ section on MDN for information regarding +testing with Marionette. + +.. _Marionette Tests: https://developer.mozilla.org/en/Marionette/Tests + +Session Management +------------------ +A session is a single instance of a Marionette client connected to a Marionette +server. Before you can start executing commands, you need to start a session +with :func:`start_session() <Marionette.start_session>`: + +.. parsed-literal:: + from marionette_driver.marionette import Marionette + + client = Marionette('localhost', port=2828) + client.start_session() + +This returns a session id and an object listing the capabilities of the +Marionette server. For example, a server running on Firefox Desktop will +have some features which a server running from Firefox Android won't. +It's also possible to access the capabilities using the +:attr:`~Marionette.session_capabilities` attribute. After finishing with a +session, you can delete it with :func:`~Marionette.delete_session()`. Note that +this will also happen automatically when the Marionette object is garbage +collected. + +Context Management +------------------ +Commands can only be executed in a single window, frame and scope at a time. In +order to run commands elsewhere, it's necessary to explicitly switch to the +appropriate context. + +Use :func:`~Marionette.switch_to_window` to execute commands in the context of a +new window: + +.. parsed-literal:: + original_window = client.current_window_handle + for handle in client.window_handles: + if handle != original_window: + client.switch_to_window(handle) + print("Switched to window with '{}' loaded.".format(client.get_url())) + client.switch_to_window(original_window) + +Similarly, use :func:`~Marionette.switch_to_frame` to execute commands in the +context of a new frame (e.g an <iframe> element): + +.. parsed-literal:: + iframe = client.find_element(By.TAG_NAME, 'iframe') + client.switch_to_frame(iframe) + assert iframe == client.get_active_frame() + +Finally Marionette can switch between `chrome` and `content` scope. Chrome is a +privileged scope where you can access things like the Firefox UI itself. +Content scope is where things like webpages live. You can switch between +`chrome` and `content` using the :func:`~Marionette.set_context` and :func:`~Marionette.using_context` functions: + +.. parsed-literal:: + client.set_context(client.CONTEXT_CONTENT) + # content scope + with client.using_context(client.CONTEXT_CHROME): + #chrome scope + ... do stuff ... + # content scope restored + + +Navigation +---------- + +Use :func:`~Marionette.navigate` to open a new website. It's also possible to +move through the back/forward cache using :func:`~Marionette.go_forward` and +:func:`~Marionette.go_back` respectively. To retrieve the currently +open website, use :func:`~Marionette.get_url`: + +.. parsed-literal:: + url = 'http://mozilla.org' + client.navigate(url) + client.go_back() + client.go_forward() + assert client.get_url() == url + + +DOM Elements +------------ + +In order to inspect or manipulate actual DOM elements, they must first be found +using the :func:`~Marionette.find_element` or :func:`~Marionette.find_elements` +methods: + +.. parsed-literal:: + from marionette import HTMLElement + element = client.find_element(By.ID, 'my-id') + assert type(element) == HTMLElement + elements = client.find_elements(By.TAG_NAME, 'a') + assert type(elements) == list + +For a full list of valid search strategies, see :doc:`advanced/findelement`. + +Now that an element has been found, it's possible to manipulate it: + +.. parsed-literal:: + element.click() + element.send_keys('hello!') + print(element.get_attribute('style')) + +For the full list of possible commands, see the :class:`HTMLElement` +reference. + +Be warned that a reference to an element object can become stale if it was +modified or removed from the document. See :doc:`advanced/stale` for tips +on working around this limitation. + +Script Execution +---------------- + +Sometimes Marionette's provided APIs just aren't enough and it is necessary to +run arbitrary javascript. This is accomplished with the +:func:`~Marionette.execute_script` and :func:`~Marionette.execute_async_script` +functions. They accomplish what their names suggest, the former executes some +synchronous JavaScript, while the latter provides a callback mechanism for +running asynchronous JavaScript: + +.. parsed-literal:: + result = client.execute_script("return arguments[0] + arguments[1];", + script_args=[2, 3]) + assert result == 5 + +The async method works the same way, except it won't return until a special +`marionetteScriptFinished()` function is called: + +.. parsed-literal:: + result = client.execute_async_script(""" + setTimeout(function() { + marionetteScriptFinished("all done"); + }, arguments[0]); + """, script_args=[1000]) + assert result == "all done" + +Beware that running asynchronous scripts can potentially hang the program +indefinitely if they are not written properly. It is generally a good idea to +set a script timeout using :func:`~Marionette.timeout.script` and handling +`ScriptTimeoutException`. |