[Activerdf] query results metadata

[Eric Hanson]

Eyal Oren wrote:
> On 10/05/06/10/06 09:36 -0700, Eric Hanson wrote:
> 
>> Yeah exactly.  Here's my "dream code", a simple minimal read/write REST
>> interface to a triple store, easily accessible via XMLHttpRequest.
> Hmm. I'm not sure about the usage scenario, but I'll go along for now.
> 
> Maybe you're looking for something like ActiveResource (work-in-progress
> in Rails AFAIK), we could do that on top of ActiveRDF, as you outlined
> below.  Some suggestions:
> 
>> rdfrest.cgi
>> ---
>> #!/usr/bin/ruby
>>
>> require 'active_rdf3'

Upon further inspection, I was using the 0.2 libraries still.  I thought
that transition was a little too smooth... :-)

>> require 'cgi'
>>
>> cgi = CGI.new
>> action = cgi['action']
>>
>> print "Content-type: text/html\r\n\r\n"
>>
>> db = NodeFactory.connection( :adapter => :redland, :location =>
>> '/usr/local/redland-data/test' )
> (using new activerdf ConnectionPool.add_data_source :type => :redland etc.)

Found a bugish-type-thing where you have to explicitly require
"activerdf/adapter/redland" to get it to work.  Submitted a bug report.

> case action
> when 'query' etc.
> instead of if

Sweet action.

>> if action == 'query'
>>     query = cgi['query']
>>     # results = db.query(query)
>>     # this line grabs json results
>>     jsonResults = db.query(query, 'someJsonResultsIndicator')
> sure, but use db.execute_sparql_query (see sparql.rb in trunk)
>>     print jsonResults
>> elsif action == 'create'
>>     s = IdentifiedResource.create(cgi['s'])
>>     p = IdentifiedResource.create(cgi['p'])
> in activerdf3 this is now:
> RDFS::Resource.new cgi['s']
>>     # is object a URI or a literal?
>>     if /^[^ ]+:\/\//.match (cgi['o'])
>>         o = IdentifiedResource.create(cgi['o'])
>>     else
>>         o = Literal.create(cgi['o'])
> literals are not wrapped anymore (for now)
>>     end
>>     db.add(s,p,o)
>>     print 'success'
>> elsif action == 'delete'
>>     db.delete (cgi['s'], cgi['p'], cgi['o'])
>>     print 'success'
>> else
>>     print 'request param <em>action</em> not set or unrecognized'
>> end
> with that it should all work.
> 
>>> you can just patch activerdf to use sparql+json on redland, just look at
>>> sparql.rb and compare it to redland.rb. it should be straightforward to
>>> port json-results into the redland adapter.

I'm in over my head on this one.  Maybe I'll just wait for you to do it?

Thanks,
Eric