eZ publish Evaluation: Version 2 Vs. Version 3

eZ publish 2 is one of the most popular open content management systems on the Web today. Its successor, eZ publish 3, is a content management system and development framework that differs fundamentally from version 2.

At present, there is no way to update automatically from version 2 to version 3, although eZ Systems has planned to release an upgrade script. Until then, a user’s decision to adopt either version 2 or 3 will have far-reaching implications for the future development of their Website.

eZ publish 2 is a stable, well-tested system, but development of version 2 might be discontinued in the future. At the moment, eZ Systems does still support this version, but with limited resources. The development of eZ publish version 3 is in full swing, and offers all the associated advantages and disadvantages to its early adopters. Version 3 is high-maintenance because it contains more bugs and offers less ‘out-of-the-box’ functionality than did the previous version, but it offers more opportunities for the future development of a site.

This report provides a general framework that will allow the reader to make an informed choice between the 2 versions of the eZ publish CMS. It doesn’t attempt to establish which of the versions should be considered the ‘preferred option’. The suitability of either version will depend on the functional requirements of a site, plans for its future development and the time/project constraints experienced by the developer.

About eZ publish

eZ publish, a CMS released under an open source licence, has recently become very popular. The system includes all the features of most commercially licensed systems and offers many optional extras. The eZ publish CMS has been developed by eZ systems, a small company located in Skien, Norway (visit their site for more information).

eZ publish 2.2.x is a professional open source CMS that gives easy access to Internet sites through a user-friendly and reliable program. It is platform- and database-independent, and module based, with a total of 26 different modules available. Version 2 was first released in November 2000; the most recent version of the 2 series is 2.2.8.

eZ publish 3 is a content management system and development framework. The CMS is based on a fully customizable and extendable content model. Its stand-alone libraries can be used as a development framework for cross-platform, database-independent PHP projects. Version 3 was released on 25 March 2003. The first update of version 3 has already been released (3.0-2), which fixed some bugs that had been found in the kernel.

As the numbering of versions suggests, there are some fundamental differences between eZ publish versions 2 and 3. eZ publish 3 broadens the capabilities of version 2 towards a general application framework, providing basic data handling and display mechanisms and expanding indefinitely the possibilities for creating customized content within the system.

Whereas version 2 works with a ‘limited’ set of 26 modules, version 3 allows users to identify their own content classes and attributes. Some examples of content classes are:

• article
• forum
• product
• publication
• organization
• user account

A simple ‘article’ content class may consist of attributes such as author, title, intro and body. New classes and attributes can be simply added through the administrative back end -- no additional coding is required.

Evaluation criteria

For the purposes of this investigation, the 2 versions of eZ publish were evaluated on the basis of the following criteria:

• functionality
• flexibility
• performance
• stability

Usability was not included as a criterion because both the front- and back-end of the eZ publish application can be fully customized to meet the needs of users and content managers.

Functionality
The bigger the gap between functional requirements and actual functionality available in the default install of eZ publish, the more resources (staff, money and time) the user will have to expend on site development. In the best case scenario, customization is limited to the enhancement of the design or existing functionality. In the worst case, advanced customization requires the development of new functionality from scratch.

Advanced but poorly documented customization may turn the eZ publish system into a legacy solution that no one can extend, extract data from, or fix bugs on. Once the system is no longer truly ‘open’, the organization may be tied into an exclusive, long-term contract with the company that customized the system. Moreover, advanced customization may seriously hamper the installation of future updates, with the result that the organization could miss out on important security updates.

eZ publish 2 is a system with extensive built-in functionality that meets the needs of most small to medium-sized organizations and campaigns. The customization of existing modules is usually limited to adapting and improving eZ Article (multiple topics, alternative links, additional frontpage rows), eZ Filemanager (sorting method), eZ Search (searching additional modules) and eZ Link (sorting method). In many cases, customization also involves adding extra fields for information to a module. For example, in the case of eZ Filemanager this could be the field ‘author’ for a file. More advanced customization is often required for multilingual support, eZ Calendar, eZ Contact, or in cases where eZ Filemanager has to be converted into an ‘elibrary’.

At first glance, eZ publish 3 appears to offer much less functionality than version 2. However, as mentioned above, version 3 allows users to identify their own content classes and attributes through the administrative back end. Much of the functionality of the version 2 modules is available in some form in version 3 (see this article for more). A number of standard functional enhancements required for version 2 are available by default in version 3, and additional information fields (attributes) can be added to objects without coding. This means that it’s possible to implement advanced customization of version 3 while keeping the source code comprehensible or ‘open’, thus avoiding dependency upon a single service provider.

Version 3 has a compact design and the kernel does not need to be altered for most customizations. As a result, future upgrades are possible even if the system is highly customized. Moreover, eZ Systems is working on additional example implementations in version 3, and making it easier for others to contribute their work.

Conclusion

eZ publish 2 offers more in terms of ‘out-of-the-box’ functionality, allowing organizations with limited resources and time constraints to ‘jump start’ their Internet projects while keeping costs under control. Version 2 is flexible enough to allow functional extensions as and when they’re required, but advanced development of this system may lead to dependency on an external service provider for technical maintenance.

eZ publish 3 is ideally suited for projects that require functionality beyond that provided in the ‘standard’ modules. It allows for extensive customization, while avoiding external dependency. However, due to its flexibility, the lack of accurate and comprehensive functional specifications may cause the development process to spiral out of control. This ‘grown up’ system needs a ‘grown up’ development approach, which might not suit time- and resource-pressed organizations.