Question

I’m writing a custom view to get around the bug that displays the wrong start and end times for events in table view in Plone 4. However, when I call my view I get the following error:

Traceback (innermost last):
Module ZPublisher.Publish, line 116, in publish
Module ZPublisher.BaseRequest, line 498, in traverse
Module ZPublisher.BaseRequest, line 343, in traverseName
Module ZPublisher.BaseRequest, line 110, in publishTraverse
Module zope.component._api, line 122, in queryMultiAdapter
Module zope.component.registry, line 240, in queryMultiAdapter
Module zope.interface.adapter, line 522, in queryMultiAdapter
TypeError: __init__() takes exactly 2 arguments (3 given)

It’s been awhile since I’ve created a view, but I thought (in accordance with this) that __init__() does take 3 arguments (self, context, request). At any rate here’s what my BrowserView class looks like at the moment:

class NewEventsView(BrowserView):
    """Custom View for displaying events in a table with correct times"""

    implements(INewEventsView)

    def getCurrentEvents(self):
        """Method to return all active events in order"""
        current_events = []
        cat = getToolByName(self.context, 'portal_catalog')
        brains = cat(portal_type='Event', review_state='published', sort_on='start')
        for x in brains:
            event = x.getObject()
            if event.startDate > DateTime():
                current_events.append(event)
        return current_events

I’ve tried different variations of this adding an __init__ as in the above mentioned page shows, and just for the heck of it giving it an __init__(self, context): just to see if 2 arguments would really change anything and it gives the exact same error.

I’m testing this in a Plone 4.0.2 site on Mac OS X Snow Leopard (in a python 2.6.6 virtualenv)

BrowersView registration from browser/configure.zcml (I threw this into a theme I was also working with). I call http://localhost:8080/plone/events/new_events_view to see how the view looks and get the above error. I’ve also tried registering the view in portal_types for topic and it will give me that error upon navigating to http://localhost:8080/plone/events until I remove the view.

  <browser:page
      for="*"
      name="new_events_view"
      class=".newEventsView.NewEventsView"
      template="newEventsView.pt"
      permission="zope.Public"
      allowed_interface=".interfaces.INewEventsView"
      />

Any help would be greatly appreciated.

Also, I know it’s a small block of code, but rip it apart if you think it could be done in a better fashion, I’m a student always looking for ways to improve.

Thanks

Answer 1

You shouldn’t put any code in the __init__ method of a browser view anyways. If you want to have some custom code put it into methods on the view class or overwrite the __call__ method. The view is instantiated before a security context is available and might be instantiated multiple times per request. This can lead to a lot of surprising effects if you do any non-trivial work in it – so best just avoid doing anything in there.

In Plone 4 you would write a custom __call__ as:

from zope.publisher.browser import BrowserView

class MyView(BrowserView):

    def __call__(self):
        # do some work
        return super(MyView, self).__call__()