Gabor writes in to ask:
My application metadata (DB object definitions and module - application logic - definitions) are in my own metadata repository. We would like to use this metadata to build our own application engine. So I'd like to build ADF BC object definitions (XML files) for entity object, view object, etc. dynamically at runtime and to use the default implementation codes for these objects.My question is that how can I build the ADF BC object definitions dynamically from my own metadata?
The short answer is, it's pretty straightforward: see example #44 on my Not Yet Documented Examples page for a simple illustration of how to provide a custom implementation of the ADF BC metadata lookup mechanism.
Back in November 1999, I used this technique to build a prototype of a database-metadata-driven system for some internal brainstorming we were doing. I built a set of tables to store the basic metadata that makes up a BC4J application module, view object, and entity objects. I built an application module over these table, and used features of BC4J itself to serve up database metadata in the correct XML format that looked just like the XML format that normally JDeveloper would save out for the BC4J component metadata. I wrote a servlet that would serve up the metadata document for any given component from the "database repository".
Then, I provided a custom XMLContext lookup implementation (as shown in the aforementioned example #44) that resolved its metadata by fetching an XML document from the servlet I mentioned above, for any given a.b.c.SomeComponent that it was looking for. Of course, you wouldn't need to have a servlet involved, that was just a way I chose at the time to separate the roles of the system I was prototyping...
6:54:45 PM 
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