The Houdah WebObjects Frameworks provide a number of WebObjects extensions and utility classes.
You will find quite a few bits you may want to use in your current WebObjects project:
- Custom qualifiers (InSubqueryQualifier, InSetQualifier, ExistsInRelationshipQualifier, ...)
- Audit trail
- Rule based EO validation
The real strength of the Houdah Frameworks is the web component architecture which builds up to a rule based CRUD framework. HoudahAgileComponents are meant as a modern alternative to D2W. The framework produces perfectly clean HTML which is to be "skinned" at the application level by CSS sheets. HoudahAgileComponents is very flexible and allows for easy customization and extension through both rules and code.
The architecture builds upon HoudahViewComponents which provides the view layer. This layer provides large grain view components build from fine grained cells. The view layer could work with any control or persistence layer. The HoudahControlComponents implements a control layer focused on creating CRUD applications using EOF. The control components could be used as is: one would have to subclass an abstract controller for each "page" of the application.
HoudahAgileComponents extends the control components by concrete subclasses which call into a rule system. This makes Houdah Frameworks a powerhouse for both rapid prototyping as well as production applications. That said, Houdah Frameworks are intended for use on in-house CRUD systems. If you were to create a public web site, you would need to work on optimization.
All throughout Houdah Frameworks MVC principles are taken to the extreme. Of course the EOControl layer does not depend on the EOAccess layer, the view layer does not depend on EOF and the control layer joins them.
Pierre Bernard made two presentations at WOWODC 2008, now available as free podcasts. One is a general overview of the Houdah WebObjects frameworks, the other is about localization.