ContentRewriter "cleanup": separate GadgetRewriter and RequestRewriter, etc.

[awiner, 2009-04-15 01:05:11]

ContentRewriter supports both rewriting of gadgets and of HTTP requests.  In
practice, most rewriters are only one or the other.  There's also a
RewriterResults class that looked to introduce cacheability definitions, but was
largely ignored in practice.

This patch splits ContentRewriter into GadgetRewriter and RequestRewriter,
renames classes accordingly, and eliminates RewriterResults. 
ContentRewriterRegistry now only handles request rewriting (and is named
RequestRewriterRegistry).

[etnu00, 2009-04-15 03:06:18]

http://codereview.appspot.com/41063/diff/94/121
File
java/gadgets/src/main/java/org/apache/shindig/gadgets/render/HtmlRenderer.java
(right):

http://codereview.appspot.com/41063/diff/94/121#newcode55
Line 55: GadgetHtmlParser htmlParser) {
Looking at this, I kind of like having a class that encapsulates the rewriters
and parser. It makes testing of HtmlRenderer a little easier. Admittedly I find
it hard to justify a class that just does parse + iterate beyond that, though.

http://codereview.appspot.com/41063/diff/94/123
File
java/gadgets/src/main/java/org/apache/shindig/gadgets/render/RenderingGadgetRewriter.java
(right):

http://codereview.appspot.com/41063/diff/94/123#newcode85
Line 85: public class RenderingGadgetRewriter implements GadgetRewriter {
"Rendering" is redundant here, but I'm at a loss for a better name. 

*however*, the TODO above can be completed now that we've been using full DOM
for the last 6 months. It's safe to say that the code is 'proven' enough to do
that work (later...)

http://codereview.appspot.com/41063/diff/94/120
File
java/gadgets/src/main/java/org/apache/shindig/gadgets/render/SanitizedRenderingGadgetRewriter.java
(right):

http://codereview.appspot.com/41063/diff/94/120#newcode63
Line 63: public class SanitizedRenderingGadgetRewriter implements GadgetRewriter
{
Sanitiz[ing]GadgetRewriter?

http://codereview.appspot.com/41063/diff/94/128
File
java/gadgets/src/main/java/org/apache/shindig/gadgets/rewrite/DefaultRequestRewriterRegistry.java
(right):

http://codereview.appspot.com/41063/diff/94/128#newcode34
Line 34: public class DefaultRequestRewriterRegistry implements
RequestRewriterRegistry {
Is there more than one place that uses this? So far as I can tell it looks like
only RequestPipeline touches this.

http://codereview.appspot.com/41063/diff/94/131
File
java/gadgets/src/main/java/org/apache/shindig/gadgets/rewrite/GadgetRewriter.java
(right):

http://codereview.appspot.com/41063/diff/94/131#newcode33
Line 33: void rewrite(Gadget gadget, MutableContent content);
It would be nice if this could throw a checked exception.