Interface definition

Simple interface for our contents, using the custom Zope 3 field for relation:

>>> from infrae.plone.relations.schema import PloneRelation
>>> from zope.interface import implements, Interface
>>> class ISimpleContent(Interface):
...    """Simple interface with relation."""
...    relation = PloneRelation(title=u"A relation",
...                             relation="relation1")

In the user interface, Zope IntID are used to keep track of object. You can also use Archetype UID (check the configure.zcml file), in this case all content must comes from the Referenceable class of Archetype (Products.Archetypes.Referenceable).

Widget definition

The plone relation widget is customisable, you can select different sub-widgets to select new items to add to relation. These sub-widgets can takes arguments. For instance here, you can put a restriction on content_type.

The widget is built using CustomWidgetFactory:

>>> from infrae.plone.relations.form import PloneRelationEditWidget
>>> from infrae.plone.relations.form import PloneRelationSearchAddWidget
>>> from zope.app.form import CustomWidgetFactory
>>> widget_factory = CustomWidgetFactory(PloneRelationEditWidget,
...                                      add_widget=PloneRelationSearchAddWidget,
...                                      add_widget_args=dict(content_type='MySimpleContent'))

Currently, there is three different widgets to add relations: one which does a catalog search with user input and let select result as object for relation, one which list objects (from the catalog always), one which use a Zope 3 vocabulary as input.

The infrae.plone.relations.form.utility provides simples methods to build these widgets.

Form definition

Now, we will do a simple edit form for a content using this interface:

>>> from Products.Five.formlib import formbase
>>> from zope.formlib import form
>>> class EditSimpleContentForm(formbase.EditForm):
...    label = 'Edit form'
...    description = 'Form to edit relation'
...    form_fields = form.Fields(ISimpleContent)
...    form_fields['relation'].custom_widget = widget_factory

It’s easy ?

Real test

We added this code in the example.py file, and the form would be bind to Document. We load it now:

>>> from Products.Five.zcml import load_string
>>> load_string("""<configure xmlns="http://namespaces.zope.org/browser">
... <page name="relation.html"
...       for="infrae.plone.relations.form.example.IPloneRelationExample"
...       class="infrae.plone.relations.form.example.PloneRelationEditForm"
...       permission="cmf.ModifyPortalContent" />
... </configure>""")

And now get an authenticated browser:

>>> browser = self.getAuthenticatedBrowser()

The front-page is a document, so we should get our form:

>>> browser.open('http://nohost/plone/front-page/relation.html')
>>> 'Plone relation edit form' in browser.contents
True

So we can search for Plone in this add widget, and should get one response, since by default there is only one document with the word Plone, the front page itself:

>>> browser.getControl(name='form.relation.search_value').value='Plone'
>>> browser.getControl(name='form.relation.search_button').click()

And we got some results:

>>> add_value = browser.getControl(name='form.relation.add_value:list')
>>> add_value.getControl('Welcome to Plone').selected = True
>>> browser.getControl(name='form.relation.add_button').click()
>>> browser.getControl('Apply').click()
>>> 'Updated on' in browser.contents
True

You can look up the README.EXT.txt and example.py file for more tests and examples.

Changes

Credits

The first version of this widget have been released with the help of the Flemish government of Belgium, for the application <http://www.zonderisgezonder.be>.

You can help us as well to contribute to this product, by sending your remarks or patchs at the author email address (or ask for an SVN access).