Transformers

No, not the crazy cars that change into robot fighting machines.  And no, not that horrible movie from last year.  Transformers are snippets of PHP5 code that transform the output of a Dapp into any other format using a set of rules.  For instance, the RSS transformer takes the XML output of a Dapp using rules to determine which Dapp field should be used as the story title, which Dapp field should be used as the story date, and so on.  The Transformer infrastructure is explained in detail on the Dapper website:

http://www.dapper.net/developers/transformers/

Please contribute your code snippets and comments here on the wiki.