Description Konstantin Komissarchik 2010-07-12 20:41:46 EDT

As part of the work on the Deployment Assembly page in Helios that replaced the Java EE Module Dependencies, the existing classpath entry tagging system was made practically inaccessible. In its place, a new system for referencing classpath containers via the .component file was introduced.

This change has created a number of usability and architectural problems:

1. (Architectural) Third-party classpath containers are written to be used directly by JDT. Unlike other types of classpath entries, containers are frequently dynamic and are written to refresh on certain events as defined by the container's provider. The way a container is updated is by using IJavaProject API to tell JDT to refresh the container. By taking JDT out of the loop and evaluating containers internally, this changes seriously breaks a number of third party classpath containers.

2. (Usability) As containers are evaluated internally, they are surfaced to the user via a single entry in Project Explorer. This flattened arrangement is a considerable usability impact in many situation. Consider the case where a user has 5 user libraries with 2-3 jars in each. With normal way of referencing these libraries, the user would see 5 separate nodes in the Project Explorer. These nodes would be labeled with names given to user libraries by the user. With the new approach, all the jars are flattened into one list and the descriptive names of classpath containers are innaccessible.

3. (Usability) The existing classpath tagging facility was made more difficult to access. It used to be possible to apply/remove tag via Java EE Dependencies page. The replacement Deployment Assembly page provides no equivalent facility. 

The architectural issue outlined above makes this of critical severity. A number of third-party classpath containers will not work properly using the new reference system, that is now prominently positioned for users to encounter.

I would recommend de-emphasizing the new "Classpath Container" type of .component reference introduced in Helios and replacing it with proper access to classpath entry tags in the Deployment Assembly page.

I would further recommend (lower severity) that other classpath-type .component references be similarly de-emphasized in favor of classpath tags. There is much danger of bugs in trying to take over this function from JDT. Especially in bugs related to not picking up on updates. JDT already handles all of this. It would be great if WTP would just let it do its thing.