1Debugging
2=========
3
4.. py:currentmodule:: marionette_driver.marionette
5
6Sometimes when working with Marionette you'll run into unexpected behaviour and
7need to do some debugging. This page outlines some of the Marionette methods
8that can be useful to you.
9
10Please note that the best tools for debugging are the `ones that ship with
11Gecko`_. This page doesn't describe how to use those with Marionette. Also see
12a related topic about `using the debugger with Marionette`_ on MDN.
13
14.. _ones that ship with Gecko: https://developer.mozilla.org/en-US/docs/Tools
15.. _using the debugger with Marionette: https://developer.mozilla.org/en-US/docs/Marionette/Debugging
16
17Seeing What's on the Page
18~~~~~~~~~~~~~~~~~~~~~~~~~
19
20Sometimes it's difficult to tell what is actually on the page that is being
21manipulated. Either because it happens too fast, the window isn't big enough or
22you are manipulating a remote server! There are two methods that can help you
23out. The first is :func:`~Marionette.screenshot`::
24
25    marionette.screenshot() # takes screenshot of entire frame
26    elem = marionette.find_element(By.ID, 'some-div')
27    marionette.screenshot(elem) # takes a screenshot of only the given element
28
29Sometimes you just want to see the DOM layout. You can do this with the
30:attr:`~Marionette.page_source` property. Note that the page source depends on
31the context you are in::
32
33    print(marionette.page_source)
34    marionette.set_context('chrome')
35    print(marionette.page_source)
36