[Confab-developers] XPath implemented

[Jason I. H. <ja...@cs...>]

Ok, the code is a little unsightly right now, but InfoSpaces
now support XPath queries. I'm using the Jaxen XPath engine
to do this.

So now you can do local queries like:
http://localhost:8080/infospace/jasonh?q=//ContextTuple[@type='location.room']

which means find all ContextTuple tags that have the type attribute
equals to 'location.room'


There's a nice XPath tutorial at:
- http://www.w3schools.com/xpath/xpath_syntax.asp


Some issues:
- Be sure to use single quotes around String literals
- I'm not sure if you can do wildcards, like @type='location.*'
- I'm going to add some more URL parameters, like 'sort' and
   'numdocs'. So a query might be something like:

...?q=//ContextTuple[@type='location.room']&sort=date-ascending&numdocs=10

- What should the query return internally? Right now it
   returns a List of Elements (org.w3c.dom.Element). They get
   transformed to XML Strings in the HTTP front end.


What do you guys need for next week? Here's my current plan:
- Cleaning up the code, adding more examples to the APIs
- Creating regression test cases
- Taking a whack at the .entity-*.xml files (like properties,
   security and privacy policies, etc)

-- 
Jason I. Hong                      |  Group for User Interface Research
ja...@cs...             | University of California, Berkeley
http://www.cs.berkeley.edu/~jasonh |        http://guir.cs.berkeley.edu