.. _navigating:

Navigating
----------

The first thing you'll want to do with WebDriver is navigate to a link.  The
normal way to do this is by calling ``get`` method:

::

  driver.get("http://www.google.com")

WebDriver will wait until the page has fully loaded (that is, the ``onload``
event has fired) before returning control to your test or script.  *Be aware
that if your page uses a lot of AJAX on load then WebDriver may not know when it
has completely loaded*.  If you need to ensure such pages are fully loaded then
you can use :ref:`waits <waits>`.

Interacting with the page
~~~~~~~~~~~~~~~~~~~~~~~~~

Just being able to go to places isn't terribly useful.  What we'd really like to
do is to interact with the pages, or, more specifically, the HTML elements
within a page.  First of all, we need to find one.  WebDriver offers a number of
ways to find elements.  For example, given an element defined as::

  <input type="text" name="passwd" id="passwd-id" />

you could find it using any of::

  element = driver.find_element(By.ID, "passwd-id")
  element = driver.find_element(By.NAME, "passwd")
  element = driver.find_element(By.XPATH, "//input[@id='passwd-id']")
  element = driver.find_element(By.CSS_SELECTOR, "input#passwd-id")

You can also look for a link by its text, but be careful! The text must be an
exact match! You should also be careful when using `XPATH in WebDriver`.  If
there's more than one element that matches the query, then only the first will
be returned.  If nothing can be found, a ``NoSuchElementException`` will be
raised.

.. TODO: Is this following paragraph correct ?

WebDriver has an "Object-based" API; we represent all types of elements using
the same interface.  This means that although you may see a lot of possible
methods you could invoke when you hit your IDE's auto-complete key combination,
not all of them will make sense or be valid.  Don't worry! WebDriver will
attempt to do the Right Thing, and if you call a method that makes no sense
("setSelected()" on a "meta" tag, for example) an exception will be raised.

So, you've got an element.  What can you do with it? First of all, you may want
to enter some text into a text field::

  element.send_keys("some text")

You can simulate pressing the arrow keys by using the "Keys" class::

  element.send_keys(" and some", Keys.ARROW_DOWN)

It is possible to call `send_keys` on any element, which makes it possible to
test keyboard shortcuts such as those used on GMail.  A side-effect of this is
that typing something into a text field won't automatically clear it.  Instead,
what you type will be appended to what's already there.  You can easily clear
the contents of a text field or textarea with the `clear` method::

  element.clear()


Filling in forms
~~~~~~~~~~~~~~~~

We've already seen how to enter text into a textarea or text field, but what
about the other elements? You can "toggle" the state of the drop down, and you
can use "setSelected" to set something like an `OPTION` tag selected.  Dealing
with `SELECT` tags isn't too bad::

    element = driver.find_element(By.XPATH, "//select[@name='name']")
    all_options = element.find_elements(By.TAG_NAME, "option")
    for option in all_options:
        print("Value is: %s" % option.get_attribute("value"))
        option.click()

This will find the first "SELECT" element on the page, and cycle through each of
its OPTIONs in turn, printing out their values, and selecting each in turn.

As you can see, this isn't the most efficient way of dealing with SELECT
elements. WebDriver's support classes include one called a "Select", which
provides useful methods for interacting with these::

    from selenium.webdriver.support.ui import Select
    select = Select(driver.find_element(By.NAME, 'name'))
    select.select_by_index(index)
    select.select_by_visible_text("text")
    select.select_by_value(value)


WebDriver also provides features for deselecting all the selected options::

    select = Select(driver.find_element(By.ID, 'id'))
    select.deselect_all()

This will deselect all OPTIONs from that particular SELECT on the page.

Suppose in a test, we need the list of all default selected options, Select
class provides a property method that returns a list::

    select = Select(driver.find_element(By.XPATH, "//select[@name='name']"))
    all_selected_options = select.all_selected_options

To get all available options::

    options = select.options

Once you've finished filling out the form, you probably want to submit it. One
way to do this would be to find the "submit" button and click it::

  # Assume the button has the ID "submit" :)
  driver.find_element(By.ID, "submit").click()

Alternatively, WebDriver has the convenience method "submit" on every element.
If you call this on an element within a form, WebDriver will walk up the DOM
until it finds the enclosing form and then calls submit on that.  If the element
isn't in a form, then the ``NoSuchElementException`` will be raised::

  element.submit()


Drag and drop
~~~~~~~~~~~~~

You can use drag and drop, either moving an element by a certain amount, or on
to another element::

  element = driver.find_element(By.NAME, "source")
  target = driver.find_element(By.NAME, "target")

  from selenium.webdriver import ActionChains
  action_chains = ActionChains(driver)
  action_chains.drag_and_drop(element, target).perform()


Moving between windows and frames
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

It's rare for a modern web application not to have any frames or to be
constrained to a single window.  WebDriver supports moving between named windows
using the "switch_to.window" method::

  driver.switch_to.window("windowName")

All calls to ``driver`` will now be interpreted as being directed to the
particular window.  But how do you know the window's name? Take a look at the
javascript or link that opened it::

  <a href="somewhere.html" target="windowName">Click here to open a new window</a>

Alternatively, you can pass a "window handle" to the "switch_to.window()"
method.  Knowing this, it's possible to iterate over every open window like so::

  for handle in driver.window_handles:
      driver.switch_to.window(handle)

You can also swing from frame to frame (or into iframes)::

  driver.switch_to.frame("frameName")

It's possible to access subframes by separating the path with a dot, and you can
specify the frame by its index too.  That is::

  driver.switch_to.frame("frameName.0.child")

would go to the frame named "child" of the first subframe of the frame called
"frameName".  **All frames are evaluated as if from *top*.**

Once we are done with working on frames, we will have to come back to the parent
frame which can be done using::

  driver.switch_to.default_content()


Popup dialogs
~~~~~~~~~~~~~

Selenium WebDriver has built-in support for handling popup dialog boxes.  After
you've triggered action that would open a popup, you can access the alert with
the following::

  alert = driver.switch_to.alert

This will return the currently open alert object.  With this object, you can now
accept, dismiss, read its contents or even type into a prompt.  This interface
works equally well on alerts, confirms, prompts.  Refer to the API documentation
for more information.


Navigation: history and location
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Earlier, we covered navigating to a page using the "get" command (
``driver.get("http://www.example.com")``).  As you've seen, WebDriver has a
number of smaller, task-focused interfaces, and navigation is a useful task.  To
navigate to a page, you can use `get` method::

  driver.get("http://www.example.com")

To move backward and forward in your browser's history::

  driver.forward()
  driver.back()

Please be aware that this functionality depends entirely on the underlying
driver.  It's just possible that something unexpected may happen when you call
these methods if you're used to the behavior of one browser over another.


Cookies
~~~~~~~

Before moving to the next section of the tutorial, you may be interested in
understanding how to use cookies.  First of all, you need to be on the domain
that the cookie will be valid for:

::

  # Go to the correct domain
  driver.get("http://www.example.com")

  # Now set the cookie. This one's valid for the entire domain
  cookie = {'name' : 'foo', 'value' : 'bar'}
  driver.add_cookie(cookie)

  # And now output all the available cookies for the current URL
  driver.get_cookies()