Migrating to Drupal
Drupal allows you to customize the layouts of pages easily using an extensible theme system. A convenient way to build a custom theme for your Web site is to base it on one of the themes packaged with Drupal. You can use different themes for certain users or in association with taxonomy terms.
Various combinations of the above five ingredients will result in surprisingly diverse solutions. Search the Drupal Web site for “recipes”. If you still cannot achieve what you need, you can customize Drupal or build custom modules.
We started Planetizen's migration by making a list of all the features we would need and identifying which Drupal modules would provide that functionality. This required testing different modules and configuration settings. We identified requirements that could not be met using Drupal modules. These features would require custom development. We then developed the taxonomy, defined user roles and permissions, and decided on the work flow. To maintain the original look and feel in the Drupal-based version, we developed a custom theme. Moving to a new CMS is also a good time to rethink current business logic and improve it. We took this opportunity to prune out less-popular Web site features.
The biggest migration challenge was pulling in five years' worth of data into Drupal—more than 15,000 news stories. Drupal story and page node types provided only basic title and body attributes for a node. Each news item stored in Planetizen had several other attributes. What we needed was our own custom content type. Drupal's flexinode provides an easy way to create custom content types without programming. Unfortunately, it turned out that the flexinode route would be an inefficient solution for us. Using flexinode, each Planetizen news story would have taken up to eight separate table inserts as opposed to the standard single insert, due to the way flexinode stored data.
Drupal's wealth of third-party modules came to the rescue. We discovered that a book review module was very similar to what we needed. By examining its code, we were able to customize the book review module to create the content types we needed. We then created custom scripts to insert Planetizen's data into the appropriate fields directly in Drupal's MySQL tables.
We did encounter some limitations with Drupal. One limitation was the mechanism for maintaining time zones and daylight savings time in Drupal. Our workaround was to use only the PST/PDT time zone and manually update the time zone when it was time for a daylight savings time change. This is a known issue and is being addressed by developers.
Flexinode makes it possible to create custom node types without programming, but as we discovered, it has its limitations. The alternative is to develop custom node types as modules. Drupal provides a solid foundation for creating your own modules, but it requires programming experience. The Drupal team is addressing this issue with the Content Construction Kit (CCK), an effort currently under development that aims to make it easier to create custom node types.
One problem we ran into had nothing to do with Drupal. Our production Web server was running an older version of PHP that could not be upgraded, due to some hosting restrictions. This caused the search module to fail; however, we were able to circumvent this problem by modifying the search module. We thanked ourselves once again that we were using an open-source CMS.
Security patches and core code updates for Drupal are released on a regular basis. This is a good thing, but upgrading customized Drupal installations can be cumbersome. We recommend limiting customizations to specific modules or developing custom modules. Also, using a version control system, such as CVS or Subversion, can help in tracking your customizations against official Drupal releases.
We launched the new Drupal-based Planetizen Web site in September 2005 and received positive feedback from readers. Since the launch, we were able to add new sections and features without having to develop them from scratch (Figures 5 and 6).