zope.contentprovider

7.0 verified Mon Apr 27 auth: no python

Content Provider Framework for Zope Templates. Provides a mechanism for registering and rendering pluggable content providers (widgets, portlets) in Zope Page Templates. Current version: 7.0, released 2024-07-18. Release cadence: ad-hoc, based on Zope Toolkit releases.

pip install zope.contentprovider

Common errors

error ImportError: cannot import name 'IContentProvider' from 'zope.contentprovider' ↓

cause Incorrect import path; IContentProvider is in the 'interfaces' submodule.

fix

Use: from zope.contentprovider.interfaces import IContentProvider

error TypeError: Can't instantiate abstract class MyProvider with abstract methods render ↓

cause Missing implementation of render() method.

fix

Add a render() method that returns a string.

error zope.configuration.config.ConfigurationConflictError: Conflicting configuration for 'contentProvider' ↓

cause Duplicate registration of the same provider via ZCML.

fix

Remove duplicate ZCML directives or register only once.

Warnings

breaking In version 7.0, removed support for Python 2 and Python < 3.9. Also dropped 'zope.contentprovider.browser' module (merged functionality into 'provider'). ↓

fix Upgrade to Python >=3.9 and adjust imports: replace 'zope.contentprovider.browser' with 'zope.contentprovider.provider'.

deprecated Global content provider registration via ZCML directive (<browser:contentProvider />) is deprecated in favor of Python-based registration using zope.component. ↓

fix Use zope.component's provideAdapter or provideUtility to register providers programmatically.

gotcha ContentProviderBase.render() must return a unicode string (or bytes in Python 3). Returning None or non-string objects will cause template rendering errors. ↓

fix Ensure render() always returns a string: return '' or str() if no content.

gotcha When using TALESContentProvider expression in Page Templates, the expression engine expects the provider to be registered as a utility. Unregistered providers silently return empty string. ↓

fix Register your provider with zope.component.provideUtility(provider, IContentProvider) before template rendering.

Imports

IContentProvider

wrong

from zope.contentprovider import IContentProvider

correct

from zope.contentprovider.interfaces import IContentProvider

Incorrect import path; interface is in the 'interfaces' submodule.

ContentProviderBase

wrong

from zope.contentprovider import ContentProviderBase

correct

from zope.contentprovider.provider import ContentProviderBase

Class is in the 'provider' submodule, not in top-level package.

TALESContentProvider

wrong

from zope.contentprovider.tales import TALESContentProviderExpr

correct

from zope.contentprovider.tales import TALESContentProvider

The expression class is named TALESContentProvider, not TALESContentProviderExpr.

Quickstart

Minimal content provider implementation. Extend ContentProviderBase and implement render().

from zope.interface import implementer
from zope.contentprovider.interfaces import IContentProvider
from zope.contentprovider.provider import ContentProviderBase

@implementer(IContentProvider)
class MyProvider(ContentProviderBase):
    def __init__(self, context, request, view):
        super().__init__(context, request, view)
    def render(self):
        return '<p>Hello from MyProvider</p>'