Zope's CMF

Make your web site's workflow system operate the way your content providers and users want it to work. Develop with the Python-based content management framework.
A Simple CMF Site

Now that we have examined the CMF control panel, it's time to examine our site. Upon entering a bare CMF site, we see a main content area in the middle, with several toolbars and boxes in various places. The topmost menu has main navigation links for moving to the top of the site to member pages to the news page and for searching through the site's contents. Underneath that menu, but still in the upper-right corner, is a list of user-specific menus, beginning with My Preferences. This allows logged-in users to set their own preferences, add links to their personal list of favorites and log out. Users who have not logged in to the system are invited to do so if they already have an account or to join the system as a member if they do not yet have an account. On the left is a navigation menu that lists available folders and allows you to set up certain features, such as syndication and local roles.

If you're used to looking at Plone sites, the default CMF site might look a bit spartan but largely familiar. This is because the default CMF site is designed to be used within a custom CMS; even though it is completely functional, it is not designed to be used in real life. By defining new content types and modifying the display skins, you can have a CMS running in almost no time. And because the display logic is separate from the rest of the system, it is possible to change the look and feel relatively quickly.

Every member of a CMF site can be assigned to one or more roles: Member, Reviewer, Manager or Owner. All of these, except Reviewer, should be familiar to experienced Zope users and administrators. The additional role is necessary for handling workflow, in which reviewers must approve content before it is published to the Web.

Administrators are shown an extended menu on the left side of the screen, allowing them to look at a content view of the current folder, which lets them view or modify existing content or create new content within the folder. When you create a new object, you not only assign it an ID (what traditional web systems call a filename) and content, but also metadata that describes the content. Although you cannot change an object's type after it has been instantiated, you can change all of its parameters by returning to the content view and opening the content in question.

Each piece of content must be published before it can be visible to others. By default, new content has a status of private, but it can be published by clicking the publish link on the left menubar. Using the same interface, the site administrator can revoke an article from the site's published list. This is a great improvement over traditional web sites, where we remove links or delete files.

In addition, most content types can have discussions optionally attached to them. This is similar to the Comment on This Posting feature so popular on weblogs, allowing site visitors to add their comments to what the official site administrators have written. As you add a piece of content, you can decide if you want to accept the default site definition for discussions or if you would like to override the site-wide setting specifically for one piece.

Content Types

Exactly what are these content types that we can instantiate? Most of them are defined in the CMFDefault product, in individual .py files within lib/python/Products/CMFDefault. This product defines both the configuration tools we saw earlier in the Zope management interface and also the basic content types, such as NewsItem, Portal, Image and Link, that we can instantiate from within the CMF.

If you're like me, you are surprised and impressed by the small size of most of the default content types defined in the CMF. They range from 100 lines at the low end for NewsItem to under 350 lines for Portal. This not only means it is easy to debug and change these content types if issues come up but that adding a new content type is relatively easy.

Indeed, a number of new content types for CMF have been developed, and it seems to be a growing field. For example, if you visit the CMF Collective Project at collective.sf.net, you can see a number of CMF-related products that have been released in recent months. For example, fledgling CMF products are available for ecommerce, photo albums and weblog creation. As CMF becomes increasingly popular, you can expect to see the CMF Collective similarly grow in popularity.


Because Zope Corp. has said repeatedly that CMF is the future of Zope, and because installing a CMS can be so outrageously expensive, it is clear that Zope Corp. seriously is trying to underbid and outperform its proprietary counterparts. However, because Zope and CMF are open source, we can use them in our own projects both to learn about content management and to edit and publish different items. Next month, we dive in a bit more deeply, looking at how to write your own sample CMF content type.

Reuven M. Lerner (reuven@lerner.co.il) is a consultant specializing in open-source web/database technologies. He and his wife, Shira, recently celebrated the birth of their second daughter, Shikma Bruria. Reuven's book Core Perl was published by Prentice Hall in early 2002, and a second book about open-source web technologies will be published by Apress in 2003.



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Zope products

Anonymous's picture

Greate list of the ready for use Zope products can be found on content management software info