Chris@0: /*  $Id$
Chris@0: 
Chris@0:     Part of SWI-Prolog
Chris@0: 
Chris@0:     Author:        Jan Wielemaker
Chris@0:     E-mail:        wielemak@science.uva.nl
Chris@0:     WWW:           http://www.swi-prolog.org
Chris@0:     Copyright (C): 2004-2006, University of Amsterdam
Chris@0: 
Chris@0:     This program is free software; you can redistribute it and/or
Chris@0:     modify it under the terms of the GNU General Public License
Chris@0:     as published by the Free Software Foundation; either version 2
Chris@0:     of the License, or (at your option) any later version.
Chris@0: 
Chris@0:     This program is distributed in the hope that it will be useful,
Chris@0:     but WITHOUT ANY WARRANTY; without even the implied warranty of
Chris@0:     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
Chris@0:     GNU General Public License for more details.
Chris@0: 
Chris@0:     You should have received a copy of the GNU Lesser General Public
Chris@0:     License along with this library; if not, write to the Free Software
Chris@0:     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
Chris@0: 
Chris@0:     As a special exception, if you link this library with other files,
Chris@0:     compiled with a Free Software compiler, to produce an executable, this
Chris@0:     library does not by itself cause the resulting executable to be covered
Chris@0:     by the GNU General Public License. This exception does not however
Chris@0:     invalidate any other reasons why the executable file might be covered by
Chris@0:     the GNU General Public License.
Chris@0: */
Chris@0: 
Chris@0: :- module(http_sparql,
Chris@0: 	  [ sparql_reply/1
Chris@0: 	  ]).
Chris@0: :- use_module(user_db).
Chris@0: :- use_module(library(lists)).
Chris@0: :- use_module(library(rdf_write)).
Chris@0: :- use_module(library('http/http_parameters')).
Chris@0: :- use_module(library('http/http_dispatch')).
Chris@0: :- use_module(sparql).
Chris@0: :- use_module(sparql_xml_result).
Chris@0: 
Chris@0: :- http_handler('/sparql/', sparql_reply, []).
Chris@0: 
Chris@0: %%	sparql_reply(+Request)
Chris@0: %
Chris@0: %	HTTP handler for SPARQL requests.  Typically mounted on
Chris@0: %	=|/sparql/|=
Chris@0: 
Chris@0: sparql_reply(Request) :-
Chris@0: 	http_parameters(Request,
Chris@0: 			[ query(Query),
Chris@0: 			  'default-graph-uri'(DefaultGraphs),
Chris@0: 			  'named-graph-uri'(NamedGraphs)
Chris@0: 			],
Chris@0: 			[ attribute_declarations(sparql_decl)
Chris@0: 			]),
Chris@0: 	append(DefaultGraphs, NamedGraphs, AllGraphs),
Chris@0: 	authorized(read(AllGraphs, query)),
Chris@0: 	statistics(cputime, CPU0),
Chris@0: 	sparql_compile(Query, Compiled,
Chris@0: 		       [ type(Type),
Chris@0: 			 ordered(Ordered),
Chris@0: 			 distinct(Distinct)
Chris@0: 			 %,entailment(lit)
Chris@0: 		       ]),
Chris@0: 	findall(R, sparql_run(Compiled, R), Rows),
Chris@0: 	statistics(cputime, CPU1),
Chris@0: 	CPU is CPU1 - CPU0,
Chris@0: 	write_result(Type, Rows,
Chris@0: 		     [ cputime(CPU),
Chris@0: 		       ordered(Ordered),
Chris@0: 		       distinct(Distinct)
Chris@0: 		     ]).
Chris@0: 			
Chris@0: write_result(ask, [True], Options) :- !,
Chris@0: 	format('Transfer-encoding: chunked~n'),
Chris@0: 	format('Content-type: application/sparql-results+xml; charset=UTF-8~n~n'),
Chris@0: 	sparql_write_xml_result(current_output, ask(True), Options).
Chris@0: write_result(select(VarNames), Rows, Options) :- !,
Chris@0: 	format('Transfer-encoding: chunked~n'),
Chris@0: 	format('Content-type: application/sparql-results+xml; charset=UTF-8~n~n'),
Chris@0: 	sparql_write_xml_result(current_output, select(VarNames, Rows), Options).
Chris@0: write_result(_, RDF, _Options) :-
Chris@0: 	format('Content-type: application/rdf+xml; charset=UTF-8~n~n'),
Chris@0: 	rdf_write_xml(current_output, RDF).
Chris@0: 
Chris@0: 
Chris@0: %%	sparql_decl(+OptionName, -Options)
Chris@0: %	
Chris@0: %	Default   options   for   specified     attribute   names.   See
Chris@0: %	http_parameters/3.
Chris@0: 
Chris@0: sparql_decl(query,
Chris@0: 	    []).
Chris@0: sparql_decl('default-graph-uri',
Chris@0:  	    [ zero_or_more
Chris@0: 	    ]).
Chris@0: sparql_decl('named-graph-uri',
Chris@0:  	    [ zero_or_more
Chris@0: 	    ]).