Hi, >From the funky prototypes department: I was talking to a colleague this week about how to minimize the amount of code in presentation templates, and we came up with the idea of having a setup script run at the beginning of the request processing, to prepare values, functions, iterators etc. for rendering scripts.
I have created a prototype at https://svn.apache.org/repos/asf/sling/whiteboard/bdelacretaz/request-context - to play with it, install it, request http://localhost:8080/apps/requestcontext.html and see the commented scripts under /apps/requestcontext [2] Here's how this works: A Filter finds and executes the script that would process the same request as the current one if it had the "setup" extension, before the actual request processing takes place. In our example that's /apps/requestcontext/setup.ecma which contains things like rc.u.title = "Here's the title for " + rc.path + ", computed at " + new Date(); The rc object is our "request context", that provides easy access to standard (rc.<name>) and freely defined user values (rc.u.<name>). You can then use the rc object in the rendering script, which in this case would contain just <h1><%= rc.u.title %></h1> but the title building logic is neatly separated in its own script, reusable, doesn't pollute rendering etc. This might be especially useful in the context of templating languages like Sightly [1] that want to avoid code in rendering templates. The setup script can also play the role of a mini-controller, as it can redirect, fail or forward the current request. My prototype doesn't require any changes to the Sling code, so we can very keep that as an experimental extension for now, if we want to move it out of the whiteboard. Feedback is welcome as usual. -Bertrand [1] http://www.pro-vision.de/content/medialib/pro-vision/production/adaptto/2013/adaptto2013-sightly-gabriel-walt-honwai-wong-senol-tas-pdf/_jcr_content/renditions/rendition.file/adaptto2013-sightly-gabriel-walt-honwai-wong-senol-tas.pdf [2] https://svn.apache.org/repos/asf/sling/whiteboard/bdelacretaz/request-context/src/main/resources/SLING-CONTENT/apps/requestcontext
