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) 2009-2020, University of Amsterdam 7 VU University Amsterdam 8 CWI, Amsterdam 9 All rights reserved. 10 11 Redistribution and use in source and binary forms, with or without 12 modification, are permitted provided that the following conditions 13 are met: 14 15 1. Redistributions of source code must retain the above copyright 16 notice, this list of conditions and the following disclaimer. 17 18 2. Redistributions in binary form must reproduce the above copyright 19 notice, this list of conditions and the following disclaimer in 20 the documentation and/or other materials provided with the 21 distribution. 22 23 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 26 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 27 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 28 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 29 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 30 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 31 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 33 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 34 POSSIBILITY OF SUCH DAMAGE. 35*/ 36 37:- module(rdf_portray, 38 [ rdf_portray_as/1, % +Style 39 rdf_portray_lang/1 % +Lang 40 ]). 41:- use_module(library(semweb/rdf_db),[rdf_global_id/2,rdf_has/3]). 42:- use_module(library(semweb/rdfs),[rdfs_ns_label/2]). 43 44:- autoload(library(error),[must_be/2]). 45:- autoload(library(lists),[member/2]). 46 47/** <module> Portray RDF resources 48 49This module defines rules for user:portray/1 to help tracing and 50debugging RDF resources by printing them in a more concise 51representation and optionally adding comment from the label field to 52help the user interpreting the URL. The main predicates are: 53 54 * rdf_portray_as/1 defines the overall style 55 * rdf_portray_lang/1 selects languages for extracting label comments 56 57@tbd Define alternate predicate to use for providing a comment 58@tbd Use rdf:type if there is no meaningful label? 59@tbd Smarter guess whether or not the local identifier might be 60 meaningful to the user without a comment. I.e. does it look 61 `word-like'? 62*/ 63 64:- dynamic 65 style/1, 66 lang/1. 67 68%! rdf_portray_as(+Style) is det. 69% 70% Set the style used to portray resources. Style is one of: 71% 72% $ =|prefix:id|= : 73% Write as NS:ID, compatible with what can be handed to 74% the rdf predicates. This is the default. 75% 76% $ =writeq= : 77% Use quoted write of the full resource. 78% 79% $ =|prefix:label|= : 80% Write namespace followed by the label. This format 81% cannot be handed to rdf/3 and friends, but can be 82% useful if resource-names are meaningless identifiers. 83% 84% $ =|prefix:id=label|= : 85% This combines prefix:id with prefix:label, providing both human 86% readable output and output that can be pasted into the 87% commandline. 88 89rdf_portray_as(Style) :- 90 must_be(oneof([writeq, prefix:id, prefix:label, prefix:id=label]), Style), 91 retractall(style(_)), 92 assert(style(Style)). 93 94%! rdf_portray_lang(+Lang) is det. 95% 96% If Lang is a list, set the list or preferred languages. If it is 97% a single atom, push this language as the most preferred 98% language. 99 100rdf_portray_lang(Lang) :- 101 ( is_list(Lang) 102 -> must_be(list(atom), Lang), 103 retractall(lang(_)), 104 forall(member(L,Lang), assert(lang(L))) 105 ; must_be(atom, Lang), 106 asserta(lang(Lang)) 107 ). 108 109try_lang(L) :- lang(L). 110try_lang(_). 111 112 113:- multifile 114 user:portray/1. 115 116user:portray(URL) :- 117 atom(URL), 118 http_url(URL), 119 !, 120 ( style(Style) 121 -> true 122 ; Style = prefix:id 123 ), 124 portray_url(Style, URL). 125user:portray(URL) :- 126 atom(URL), 127 atom_concat('_:file://', URL2, URL), 128 sub_atom(URL2, S, _, A, #), 129 sub_atom(URL2, _, A, 0, Local), 130 sub_atom(URL2, 0, S, _, Path), 131 file_base_name(Path, Base), 132 format('_:~w#~w', [Base, Local]). 133 134http_url(URL) :- sub_atom(URL, 0, _, _, 'http://'), !. 135http_url(URL) :- sub_atom(URL, 0, _, _, 'https://'), !. 136 137portray_url(writeq, URL) :- 138 writeq(URL). 139portray_url(prefix:id, URL) :- 140 ( rdf_global_id(NS:Id, URL) 141 -> writeq(NS:Id) 142 ; writeq(URL) 143 ). 144portray_url(prefix:id=label, URL) :- 145 ( rdf_global_id(NS:Id, URL) 146 -> Value = NS:Id 147 ; Value = URL 148 ), 149 ( Id \== '', 150 ( ( try_lang(Lang), 151 rdf_has(URL, rdfs:label, literal(lang(Lang, Label))) 152 -> nonvar(Lang), 153 \+ label_is_id(Label, Id) 154 ) 155 -> format('~q/*"~w"@~w*/', [Value, Label, Lang]) 156 ; rdf_has(URL, rdfs:label, literal(type(Type, Label))), 157 nonvar(Type), 158 \+ label_is_id(Label, Id) 159 -> ( rdf_global_id(TNS:TId, Type) 160 -> TVal = TNS:TId 161 ; TVal = Type 162 ), 163 format('~q/*"~w"^^~w*/', [Value, Label, TVal]) 164 ; rdf_has(URL, rdfs:label, literal(Label)), 165 atom(Label), 166 Label \== Id 167 -> format('~q/*"~w"*/', [Value, Label]) 168 ) 169 -> true 170 ; writeq(Value) 171 ). 172portray_url(prefix:label, URL) :- 173 rdfs_ns_label(URL, Label), 174 write(Label). 175 176label_is_id(_, Var) :- 177 var(Var), !, fail. 178label_is_id(Label, Label) :- !. 179label_is_id(L0, L1) :- 180 downcase_atom(L0, Lwr), 181 downcase_atom(L1, Lwr)