tools/telemetry/telemetry/page/actions/wait.py

# Copyright (c) 2012 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import re
import time

from telemetry.core import util
from telemetry.page.actions import page_action

class WaitAction(page_action.PageAction):
  def __init__(self, attributes=None):
    self.timeout = 60
    super(WaitAction, self).__init__(attributes)

  def RunsPreviousAction(self):
    return (getattr(self, 'condition', None) == 'navigate' or
            getattr(self, 'condition', None) == 'href_change')

  def RunAction(self, page, tab, previous_action):
    tab.ExecuteJavaScript(
        'console.time("' + self.GetTimelineMarkerLabel() + '")')

    if hasattr(self, 'seconds'):
      time.sleep(self.seconds)

    elif getattr(self, 'condition', None) == 'navigate':
      if not previous_action:
        raise page_action.PageActionFailed('You need to perform an action '
                                           'before waiting for navigate.')
      previous_action.WillRunAction(page, tab)
      action_to_perform = lambda: previous_action.RunAction(page, tab, None)
      tab.PerformActionAndWaitForNavigate(action_to_perform, self.timeout)

    elif getattr(self, 'condition', None) == 'href_change':
      if not previous_action:
        raise page_action.PageActionFailed('You need to perform an action '
                                           'before waiting for a href change.')
      previous_action.WillRunAction(page, tab)
      old_url = tab.EvaluateJavaScript('document.location.href')
      previous_action.RunAction(page, tab, None)
      util.WaitFor(lambda: tab.EvaluateJavaScript(
          'document.location.href') != old_url, self.timeout)

    elif getattr(self, 'condition', None) == 'element':
      if hasattr(self, 'text'):
        callback_code = 'function(element) { return element != null; }'
        util.WaitFor(
            lambda: util.FindElementAndPerformAction(
                tab, self.text, callback_code), self.timeout)
      elif hasattr(self, 'selector'):
        util.WaitFor(lambda: tab.EvaluateJavaScript(
             'document.querySelector("%s") != null' % re.escape(self.selector)),
             self.timeout)
      elif hasattr(self, 'xpath'):
        code = ('document.evaluate("%s",'
                                   'document,'
                                   'null,'
                                   'XPathResult.FIRST_ORDERED_NODE_TYPE,'
                                   'null)'
                  '.singleNodeValue' % re.escape(self.xpath))
        util.WaitFor(lambda: tab.EvaluateJavaScript('%s != null' % code),
             self.timeout)
      else:
        raise page_action.PageActionFailed(
            'No element condition given to wait')
    elif hasattr(self, 'javascript'):
      util.WaitFor(lambda: tab.EvaluateJavaScript(self.javascript),
                   self.timeout)
    else:
      raise page_action.PageActionFailed('No wait condition found')

    tab.ExecuteJavaScript(
        'console.timeEnd("' + self.GetTimelineMarkerLabel() + '")')

  def GetTimelineMarkerLabel(self):
    return 'WaitAction::RunAction'