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""" An (unfortunately somewhat contrived, and involved) acceptance test which demonstrates that it is possible to combine a few features of Athena to re-connect a widget to a newly-created server-side counterpart. In order to see the demonstration, click 'show ID', 'disconnect', then 'show ID' again. You will see that you have received a new ReconnectableElement.
Run as::
twistd -n athena-widget --element nevow.test.acceptance.reconnect.reconnect
"""
from nevow.athena import LiveElement, expose from nevow import loaders, tags from nevow._widget_plugin import ElementRenderingLivePage as OriginalPage
class ReconnectableElementRenderingLivePage(OriginalPage): """ A version of the ElementRenderingLivePage from the plugin which also has methods suitable for reconnection.
XXX: this class unfortunately uncovers some nasty corners of the LivePage API. Don't be too surprised if this ends up broken by some future fixes to that API. We should not attempt to keep this working as-is; if you do find it in a broken state, just update it to use newer, better documented APIs. """ jsClass = u'Nevow.Test.ReconnectAcceptanceTest.ReconnectingPage' def __init__(self, *a, **k): """ Make sure our interface allows the particular method we want to expose. """ super(ReconnectableElementRenderingLivePage, self).__init__(*a, **k) self.iface = ['giveElementID'] self.rootObject = self
def giveElementID(self, newID): """ Assign an ID to the widget. """ self.element.setFragmentParent(self) self._localObjects[newID] = self.element
expose(giveElementID)
# Monkey patch to cheat a little bit in the context of the widget plugin. from nevow import _widget_plugin _widget_plugin.ElementRenderingLivePage = ReconnectableElementRenderingLivePage
import itertools
counter = itertools.count().next
class ReconnectableElement(LiveElement): """ I am a live element that can disconnect and be reconnected. """ docFactory = loaders.stan( tags.div(render=tags.directive("liveElement"))[ tags.button(onclick="Nevow.Athena.page.deliveryChannel.sendCloseMessage(); return true;")["Disconnect"], tags.button(onclick=""" Nevow.Athena.Widget.get(this).callRemote('getID').addCallback(function (result) { var e = document.createElement('div'); e.appendChild(document.createTextNode('ID: '+result)); document.body.appendChild(e); }) """)["Show ID"]])
def __init__(self): """ Create a ReconnectableElement with a unique ID """ LiveElement.__init__(self) self.currentID = counter()
def getID(self): """ Retrieve my current ID. """ return self.currentID expose(getID)
def reconnect(): return ReconnectableElement()
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