[Zope3-Users] Re: z3c.form, applyChanges, IModifiedEvent

[Philipp von Weitershausen]

Darryl Cousins wrote:
> Following a post on grok-dev I learnt about additional arguments to
> ModifiedEvent.
> 
> http://mail.zope.org/pipermail/grok-dev/2007-August/001807.html
> 
> By changing z3c.form.form.applyChanges to return a dictionary of
> interfaces and names of the attributes changed (instead of the current
> bool value) then I can easily create the correct additional attributes
> within the applyChanges method of EditForm:

...

Sadly, zope.formlib doesn't send this info along either, therefore 
setting a bad example. I filed 
https://bugs.launchpad.net/zope3/+bug/98483 a while ago, just never got 
around to fix it... Thanks for reminding.


> 
> def applyChanges(form, content, data):
>     changes = {}
>     for name, field in form.fields.items():
>         # If the field is not in the data, then go on to the next one
>         if name not in data:
>             continue
>         # Get the datamanager and get the original value
>         dm = zope.component.getMultiAdapter(
>             (content, field.field), IDataManager)
>         oldValue = dm.get()
>         # Only update the data, if it is different
>         if dm.get() != data[name]:
>             dm.set(data[name])
>             # get the interface and collect changed attribute names
>             changes.setdefault(dm.field.interface, []).append(name)
>     return changes
> 
> 
> class EditForm(Form):
> 
>     ....
> 
>     def applyChanges(self, data):
>        content = self.getContent()
>        changes = applyChanges(self, content, data)
>        if changes: # testing a dict as a bool is prone to error???
>            descriptions = []
>            for interface, names in changes.items():
>                descriptions.append(zope.lifecycleevent.Attributes(interface,
>                                                                     *names))
>            zope.event.notify(
>                 zope.lifecycleevent.ObjectModifiedEvent(content, *descriptions))
>        return changes
> 
> Hopefully pypi will be back up again later today so I can do a fresh
> build of z3c.form and run the tests with my changes as set out above.
> 
> Best regards,
> Darryl Cousins


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