Introduction
============

plone.formwidget.contenttree is a z3c.form widget for use with Plone. It
uses the jQuery Autocomplete widget, and has graceful fallback for non-
Javascript browsers.

There is a single-select version (AutocompleteSelectionFieldWidget) for
Choice fields, and a multi-select one (AutocompleteMultiSelectionFieldWidget)
for collection fields (e.g. List, Tuple) with a value_type of Choice.

When using this widget, the vocabulary/source has to provide the IQuerySource
interface from z3c.formwidget.query and have a search() method.

Example Usage::

	from zope.component import adapts
	from zope.interface import Interface, implements
	from zope import schema

	from plone.z3cform import layout

	from z3c.form import form, button, field

	from plone.formwidget.contenttree import ContentTreeFieldWidget
	from plone.formwidget.contenttree import MultiContentTreeFieldWidget
	from plone.formwidget.contenttree import PathSourceBinder


	class ITestForm(Interface):

	    buddy = schema.Choice(title=u"Buddy object",
	                          description=u"Select one, please",
	                          source=PathSourceBinder(portal_type='Document'))

	    friends = schema.List(
	        title=u"Friend objects",
	        description=u"Select as many as you want",
	        value_type=schema.Choice(
	            title=u"Selection",
	            source=PathSourceBinder(portal_type='Document')))


	class TestAdapter(object):
	    implements(ITestForm)
	    adapts(Interface)

	    def __init__(self, context):
	        self.context = context

	    def _get_buddy(self):
	        return None
	    def _set_buddy(self, value):
	        print "setting", value
	    buddy = property(_get_buddy, _set_buddy)

	    def _get_friends(self):
	        return []
	    def _set_friends(self, value):
	        print "setting", value
	    friends = property(_get_friends, _set_friends)


	class TestForm(form.Form):
	    fields = field.Fields(ITestForm)
	    fields['buddy'].widgetFactory = ContentTreeFieldWidget
	    fields['friends'].widgetFactory = MultiContentTreeFieldWidget
	    # To check display mode still works, uncomment this and hit refresh.
	    #mode = 'display'

	    @button.buttonAndHandler(u'Ok')
	    def handle_ok(self, action):
	        data, errors = self.extractData()
	        print data, errors

	TestView = layout.wrap_form(TestForm)