1/* Part of SWI-Prolog 2 3 Author: Jan Wielemaker 4 E-mail: J.Wielemaker@vu.nl 5 WWW: http://www.swi-prolog.org 6 Copyright (c) 2010-2018, University of Amsterdam 7 All rights reserved. 8 9 Redistribution and use in source and binary forms, with or without 10 modification, are permitted provided that the following conditions 11 are met: 12 13 1. Redistributions of source code must retain the above copyright 14 notice, this list of conditions and the following disclaimer. 15 16 2. Redistributions in binary form must reproduce the above copyright 17 notice, this list of conditions and the following disclaimer in 18 the documentation and/or other materials provided with the 19 distribution. 20 21 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 29 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 31 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 POSSIBILITY OF SUCH DAMAGE. 33*/ 34 35:- module(rdf_io, 36 [ write_table/2, % +Row, +Options 37 write_graph/2, % +Triples, +Options 38 get_triples/3 % +Input, -Triples, +Options 39 ]). 40:- use_module(library('semweb/rdf_db')). 41:- use_module(library(rdf_write)). 42:- use_module(library(rdf)). 43:- use_module(library(lists)). 44 45:- multifile 46 write_table/4, % +Format, +Serialization, +Rows, +Options 47 write_graph/4, % +Format, +Serialization, +Triples, +Options 48 get_triples/4. % +Format, +Input, -Triples, +Options 49 50/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 51This module acts as a dispatcher module, allowing other modules to add 52clauses for write_table/4 and write_graph/4 and thus providing 53additional output formats without modifications to the kernel source. 54- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
row(C1, C2, ...). Options specifies additional processing
options. Defined options are:
vars and atom-arguments describing the names
of each subsequent column. For Example:
variables(vars('Name', 'Address'))
The output hooks may support additional options.
85write_table(Rows, Options) :-
86 needed_option(result_format(Format), Options),
87 needed_option(serialization(Serialization), Options),
88 write_table(Format, Serialization, Rows, Options).rdf(S,P,O) triples.
Options:
104write_graph(Triples, Options) :- 105 needed_option(serialization(Serialization), Options), 106 ( Serialization == rdfxml 107 -> ( memberchk(result_format(Format), Options) 108 -> true 109 ; Format = xml 110 ) 111 ; option(result_format(Format), Options) 112 -> true 113 ; Format = Serialization 114 ), 115 write_graph(Format, Serialization, Triples, Options). 116 117 118 /******************************* 119 * READING * 120 *******************************/
127get_triples(Input, Triples, Options0) :-
128 select(data_format(Format), Options0, Options),
129 get_triples(Format, Input, Triples, Options).rdf(S,P,O) for a given
Format. The default implementation supports rdfxml by means of
load_rdf/3.137get_triples(rdfxml, Input, Triples, Options) :- 138 !, 139 load_rdf(Input, Triples, Options). 140 141 142 /******************************* 143 * HOOK * 144 *******************************/
xml and Serialization = rdfxml. It uses
rdf_write_xml/2 to emit the graph.156write_graph(xml, rdfxml, Triples, Options) :- 157 option(mimetype(Type), Options, 'application/rdf+xml'), 158 format('Transfer-encoding: chunked~n'), 159 format('Content-type: ~w; charset=UTF-8~n~n', [Type]), 160 rdf_write_xml(current_output, Triples). 161 162 163 /******************************* 164 * UTIL * 165 *******************************/ 166 167needed_option(Term, Options) :- 168 memberchk(Term, Options), 169 !. 170needed_option(Term, _) :- 171 functor(Term, Name, _), 172 throw(error(existence_error(option, Name), _))