z3c.relationfieldui 0.2

A widget for z3c.relationfield.

This package implements a zope.formlib compatible widget for relations as defined by z3c.relationfield.

This package does not provide a z3c.form widget for z3c.relationfield, but it is hoped that will eventually be developed as well (in another package).

Setup

In order to demonstrate our widget, we need to first set up a relation field (for the details of this see z3c.relationfield’s documentation):

>>> from z3c.relationfield import Relation
>>> from zope.interface import Interface
>>> class IItem(Interface):
...   rel = Relation(title=u"Relation")
>>> from z3c.relationfield.interfaces import IHasRelations
>>> from persistent import Persistent
>>> from zope.interface import implements
>>> class Item(Persistent):
...   implements(IItem, IHasRelations)
...   def __init__(self):
...     self.rel = None
>>> from zope.app.component.site import SiteManagerContainer
>>> from zope.app.container.btree import BTreeContainer
>>> class TestApp(SiteManagerContainer, BTreeContainer):
...   pass

Set up the application with the right utilities:

>>> root = getRootFolder()['root'] = TestApp()
>>> from zope.app.component.site import LocalSiteManager
>>> root.setSiteManager(LocalSiteManager(root))
>>> from zope.app.component.hooks import setSite
>>> setSite(root)
>>> from zope.app.intid import IntIds
>>> from zope.app.intid.interfaces import IIntIds
>>> root['intids'] = intids = IntIds()
>>> sm = root.getSiteManager()
>>> sm.registerUtility(intids, provided=IIntIds)
>>> from z3c.relationfield import RelationCatalog
>>> from zc.relation.interfaces import ICatalog
>>> root['catalog'] = catalog = RelationCatalog()
>>> sm.registerUtility(catalog, provided=ICatalog)

Items a and b with a relation from b to a:

>>> root['a'] = Item()
>>> from z3c.relationfield import RelationValue
>>> b = Item()
>>> from zope import component
>>> from zope.app.intid.interfaces import IIntIds
>>> intids = component.getUtility(IIntIds)
>>> a_id = intids.getId(root['a'])
>>> b.rel = RelationValue(a_id)
>>> root['b'] = b

We also need to set up a utility that knows how to generate an object path for a given object, and back:

>>> import grokcore.component as grok
>>> from z3c.objpath.interfaces import IObjectPath
>>> class ObjectPath(grok.GlobalUtility):
...   grok.provides(IObjectPath)
...   def path(self, obj):
...       return obj.__name__
...   def resolve(self, path):
...       return root[path]
>>> grok.testing.grok_component('ObjectPath', ObjectPath)
True

The relation widget

The relation widget can be looked up for a relation field. The widget will render with a button that can be used to set the relation. Pressing this button will show a pop up window. The URL implementing the popup window is defined on a special view that needs to be available on the context object (that the relation is defined on). This view must be named “explorerurl”. We’ll provide one here:

>>> from zope.interface import Interface
>>> import grokcore.view
>>> class ExplorerUrl(grokcore.view.View):
...   grok.context(Interface)
...   def render(self):
...      return 'http://grok.zope.org'

Now we can Grok the view:

>>> grok.testing.grok_component('ExplorerUrl', ExplorerUrl)
True

Let’s take a look at the relation widget now:

>>> from zope.publisher.browser import TestRequest
>>> from z3c.relationfieldui import RelationWidget
>>> request = TestRequest()
>>> widget = RelationWidget(IItem['rel'], request)
>>> print widget()
<input class="textType" id="field.rel" name="field.rel" size="20" type="text" value=""  /><input class="buttonType" onclick="Z3C.relation.popup(this.previousSibling, 'http://grok.zope.org')" type="button" value="get relation" />

Relation display widget

The display widget for relation will render a URL to the object it relates to. What this URL will be exactly can be controlled by defining a view on the object called “relationurl”. Without such a view, the display widget will link directly to the object:

>>> from z3c.relationfieldui import RelationDisplayWidget
>>> widget = RelationDisplayWidget(IItem['rel'], request)

We have to set the widget up with some data:

>>> widget._data = b.rel

The widget will point to the plain URL of rel’s to_object:

>>> print widget()
<a href="http://127.0.0.1/root/a">a</a>

Now we register a special relationurl view:

>>> class RelationUrl(grokcore.view.View):
...   grok.context(Interface)
...   def render(self):
...      return self.url('edit')
>>> grok.testing.grok_component('RelationUrl', RelationUrl)
True

We should now see a link postfixed with /edit:

>>> print widget()
<a href="http://127.0.0.1/root/a/edit">a</a>

CHANGES

0.2 (2009-01-08)

• Update the value of the input field using .value instead of using setAttribute('value', ...). The latter did not update dynamically updated input fields, and the former does.

• z3c.relationfield does not use IRelationInfo anymore and instead exposes create_relation. Use this instead.

0.1.1 (2008-12-10)

• Small internet Explorer compatibility tweaks.

0.1 (2008-12-05)

• Initial public release.

Download