collective.relateditems 0.1.0

Backporting Plone 4 related items viewlet into Plone 3

Introduction

This product is done only for Plone 3. It backports the Plone 4 related contents viewlet to old Plone 3 versions. Do not install this on Plone 4. Really.

You could need this package if and only if you have a product that you want to be compatible with Plone 3 and Plone 4, keeping the content’s view template at the Plone 4 style.

Product details

One of the most problematic change done in Plone 4 is the removal of related contents area from common views, replaced with a more flexible viewlet.

Commonly every Plone 3 contents view contains a part of code like this:

...
<div metal:use-macro="here/document_relateditems/macros/relatedItems">
   show related items if they exist
</div>
...

Removing this code and transform this as a viewlet has been a great change. However this is a problem for developers that still take care of Plone 3 compatibility:

• If we keep the “Plone 3 style” template (as above) we will see a doubled related contents area on Plone 4.

• If we remove the related contents part from our template, we won’t see related contents in Plone 3 (so we removed part of our compatibility).

But we can do better. This product gives to Plone a related items viewlet (as Plone 4 do) compatible with Plone 3, keeping Plone 3 CSS styles.

What you need is to update your template to Plone 4 layout (removing the explicit related items area) but make it compatible with this product.

Guide for 3rd party products

If you want to fix a 3rd party product that is already using the Plone 4 related items style, so you don’t see related anymore when using it on Plone 3, you simply need fix your buildout:

• add collective.relateditems to you eggs

• add to a .zcml this piece of code (explicitly in one of yours packages, or using zcml-additional):

  <include package="collective.relateditems" />
  <class class="your.product.content.YourContentClass">
      <implements interface="collective.relateditems.interfaces.IRelatedItemsEnabledContent"/>
  </class>

Note that you don’t need to change anything inside the 3rd party code.

Guide for products you own

If you are a product developer and you want to make your product fully compatible with Plone 4 but also Plone 3, your can also choose to hide to your users all configuration difficulties. You need to change something in your code.

First of all, you need to make your product based on collective.relateditems only when you are in a Plone 3 environment. The common way is to check the Python version in your setup.py:

>>> import os, sys
...
>>> install_requires = ['setuptools',
...                     'Products.CMFPlone',
...                     # other dependencies
...                     ]
...
>>> if sys.version_info < (2, 6):
...     install_requires.append('collective.relateditems')

Then the product definition:

>>> setup(name='your.product',
...     # more
...     install_requires=install_requires,
...     #more
... )

After that you need to proper define your configure.zcml:

<configure zcml:condition="installed collective.relateditems">
    <include package="collective.relateditems" />
        <class class="your.product.content.YourContentClass">
        <implements interface="collective.relateditems.interfaces.IRelatedItemsEnabledContent"/>
    </class>
</configure>

You can also make your YourContentClass Python class implementing the IRelatedItemsEnabledContent but you still need to remember that Plone 4 environment will not have this interface available.

That’s all.

Changelog

0.1.0 (2011-12-29)

• Initial release