My Current Data-Source Musings

Mon Nov 26 18:41:48 EST 2012

Tags: mvc

My quest to find the ideal way to access data in XPages continues. Each time I make a new project, I come up with a slight variation on my previous theme, improving in one or more of the various conflicting factors involved. The problem, as always, is that the standard xp:dominoView and xp:dominoDocument data sources alone are insufficient to properly separate business logic from presentation. On the other hand, accessing view data in a way that is both efficient and flexible via just the standard Java API is a non-trivial prospect. The advantage to using xp:dominoView in particular is that IBM already did an incredible amount of work making performance passable when dealing with cases of resorting, key-lookups, FT searches, response hierarchies, and the like.

The ideal method would build upon the efficient-access and serialization work already done while retaining that Rails-like collection-fetching and relation code from my forum attempts. Accordingly, I'm trying something a bit different with my latest project: I extended xp:dominoView to be able to take another parameter, modelClass, that is the class name of the objects it should return, rather than just DominoViewEntry. In turn, the objects I'm using wrap the real DominoViewEntry and allow for transparent access to the document (as needed, e.g. when a requested field is not a column) and the usual benefits of writing Java classes: namely, I can write code to handle field-change side effects without having to care about the logic behind that in the XPage itself.

This is sort of a half-formed idea so far, and I'm not 100% comfortable with it, but I think it's promising. Ideally, there wouldn't be any data sources written into the XPage itself at all (since it should be just a View), but that's sort of a necessity given the current state of things. This should be a reasonable next-best thing, and maybe a stepping stone to a new, faster, and cleaner data-access method.

The end goal of all this is to make it so that creating a new data "type" is very straightforward but still more declarative and structured than just making a new form name in the xp:dominoDocument data source. There should be classes to go with each type, but those classes should be very simple and easy to write. The quest continues!

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