Appendix: Frequently asked questions

How to use ChromeDriver ?

Download the latest `chromdriver from download page

<http://code.google.com/p/chromium/downloads/list>`_. Unzip the

file::

You should see a ``chromedriver`` executable. Now you can instance of

Chrome WebDriver like this::

The rest of the example should work as given in other other

documentation.

Does Selenium 2 supports XPath 2.0 ?

Ref: http://seleniumhq.org/docs/03_webdriver.html#how-xpath-works-in-webdriver

Selenium delegate XPath queries down to the browser's own XPath

engine, so Selenium support XPath supports whatever the browser

supports. In browsers which don't have native XPath engines (IE

6,7,8), Selenium support XPath 1.0 only.

How to scroll down to the bottom of a page ?

Ref: http://blog.varunin.com/2011/08/scrolling-on-pages-using-selenium.html

You can use the `execute_script` method to execute javascript on the

loaded page. So, you can call the JavaScript API to scroll to the

bottom or any other position of a page.

Here is an example to scroll to the bottom of a page::

The `window <http://www.w3schools.com/jsref/obj_window.asp>`_ object

in DOM has a `scrollTo

<http://www.w3schools.com/jsref/met_win_scrollto.asp>`_ method to

scroll to any position of an opened window. The `scrollHeight

<http://www.w3schools.com/jsref/dom_obj_all.asp>`_ is a common

property for all elements. The `document.body.scrollHeight` will give

the height of the entire body of the page.

Getting Started

Simple Usage

If you have installed Selenium server and Python bindings and able to

run the server, you can start using it from Python like this.

::

The above script can be saved into a file (eg:-

`python_org_search.py`), then it can be run like this::

The `python` which you are running should have the `selenium` module

installed.

Walk through of the example

The `selenium.webdriver` module provides all the WebDriver

implementations. Currently supported WebDriver implementations are

Firefox, Chrome, Ie and Remote. The `Keys` class provide keys in the

keyboard like RETURN, F1, ALT etc.

::

Next, the instance of Firefox WebDriver is created.

::

The `driver.get` method will navigate to a page given by the URL.

WebDriver will wait until the page has fully loaded (that is, the

"onload" event has fired) before returning control to your test or

script. It's worth noting that if your page uses a lot of AJAX on

load then WebDriver may not know when it has completely loaded.::

The next line is an assertion to confirm that title has "Python" word

in it::

WebDriver offers a number of ways to find elements using one of the

`find_element_by_*` methods. For example, the input text element can

be located by its `name` attribute using `find_element_by_name`

method. Detailed explanation of findind elements is available in the

:ref:`locating-elements` chapter::

Next we are sending keys, this is similar to entering keys using your

keyboard. Special keys can be send using `Keys` class imported from

`selenium.webdriver.common.keys`::

After submission of the page, you should be reached in the Google

site::

Finally, the browser window is closed. You can also call `quit`

method instead of `close`. The `quit` will exit entire browser where

as `close` will close one tab, but if it just one tab, by default most

browser will exit entirely.::

Using Selenium to write tests

Selenium will be used mostly for writing test cases. You can write

test cases using Python's unittest module. Here is the modified

example which uses unittest module. This is a test for python.org

search functionality::

You can run the above test case from a shell like this::

Walk through of the example

Initially, all the basic modules required are imported. The `unittest

<http://docs.python.org/library/unittest.html>`_ module is a built-in

Python based on Java's JUnit. This module provides the framework for

organizing the test cases. The `selenium.webdriver` module provides

all the WebDriver implementations. Currently supported WebDriver

implementations are Firefox, Chrome, Ie and Remote. The `Keys` class

provide keys in the keyboard like RETURN, F1, ALT etc.

::

The test case class is inherited from `unittest.TestCase`.

Inheriting from `TestCase` class is the way to tell `unittest` module

that, this is a test case::

The `setUp` is part of initialization, this method will get called

before every test function which you are going to write in this test

case class. Here you are creating the instance of Firefox WebDriver.

::

This is the test case method. The first line inside this method

create a local reference to the driver object created in `setUp`

method.

::

The `driver.get` method will navigate to a page given by the URL.

WebDriver will wait until the page has fully loaded (that is, the

"onload" event has fired) before returning control to your test or

script. It's worth noting that if your page uses a lot of AJAX on

load then WebDriver may not know when it has completely loaded.::

The next line is an assertion to confirm that title has "Python" word

in it::

.. note::

The `assertIn` API is only available in Python 2.7 unittest module.

WebDriver offers a number of ways to find elements using one of the

`find_element_by_*` methods. For example, the input text element can

be located by its `name` attribute using `find_element_by_name`

method. Detailed explanation of findind elements is available in the

:ref:`locating-elements` chapter::

Next we are sending keys, this is similar to entering keys using your

keyboard. Special keys can be send using `Keys` class imported from

`selenium.webdriver.common.keys`::

After submission of the page, you should be reached in the Google

site. You can confirm it by asserting "Google" in the title::

The `tearDown` method will get called after every test method. This

is a place to do all cleanup actions. In the current method, the

browser window is closed. You can also call `quit` method instead of

`close`. The `quit` will exit all entire browser where as `close`

will close one tab, but if it just one tab, by default most browser

will exit entirely.::

Final lines are some boiler plate code to run the test suite::

Using Selenium with remote WebDriver

To use the remote WebDriver, you should have Selenium server running.

While running the Selenium server, you could see a message looks like

this::

The above line says that, you can use this URL for connecting to

remote WebDriver. Here are some examples::

The desired capabilities is a dictionary, so instead of using the

default dictionaries, you can specifies the values explicitly::

.. _glossary:

Glossary