Hi Guys,
I've been implementing the external cache validity functionality of DBPrism, and I've decided that I want to externally invalidate my transformers as well. I can see that getValidity within (for example) TraxTransformer will be fairly easy to implement with an external validity, but what I'd also like to do is create a key based on values contained within the input source for the transformation. In this case a series of record ids. I can't rely on a hash, as I need to be able to selectively clear the cache given a single valid id.
As far as I can tell, TraxTranformer's getKey method uses the URI of the inputSource as the basis for a key (including params of course.) Has anyone tried modifying this to analyse the _content_ of the input document? And if you have, do you have any tips for me? I have a horrible feeling that the performance cost of analysing the input document is going to be greater than the gains ;) I can easily write some xpath to concatenate all record ids within an input document, and then clear the cache based on any one of those ideas, but I'm sure there's a smarter idea :)
I'd appreciate any feedback you may have.
Thanks,
Corin.
Corin Moss
Lead Developer
TVNZ Interactive
+64 9 916 7367
+64 21 403 054
[EMAIL PROTECTED]
