1/* Part of SWISH 2 3 Author: Jan Wielemaker 4 E-mail: J.Wielemaker@cs.vu.nl 5 WWW: http://www.swi-prolog.org 6 Copyright (C): 2018, VU University Amsterdam 7 CWI Amsterdam 8 All rights reserved. 9 10 Redistribution and use in source and binary forms, with or without 11 modification, are permitted provided that the following conditions 12 are met: 13 14 1. Redistributions of source code must retain the above copyright 15 notice, this list of conditions and the following disclaimer. 16 17 2. Redistributions in binary form must reproduce the above copyright 18 notice, this list of conditions and the following disclaimer in 19 the documentation and/or other materials provided with the 20 distribution. 21 22 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 23 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 24 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 25 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 26 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 27 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 28 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 29 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 30 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 32 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 POSSIBILITY OF SUCH DAMAGE. 34*/ 35 36:- module(swish_html_output, 37 [ html/1, % +Spec 38 html//1, % +Spec, // 39 html/4, % {|html||quasi quotation|} 40 safe_raw_html/1 % +RawTerm 41 ]). 42:- use_module(library(http/html_write), except([html//1])). 43:- use_module(library(pengines)). 44:- use_module(library(sandbox)). 45:- use_module(library(lists)). 46:- use_module(library(error)).

SWISH HTML Output

This module provides the predicate html/1 that allows for inserting HTML into the SWISH output window as well as for evaluable cells in markdown cells of notebooks. */

66html(Spec) :- 67 pengine_self(_), 68 !, 69 make_safe_html(Spec, SafeSpec), 70 pengines_io:send_html(SafeSpec). 71html(Spec) :- 72 phrase(html(Spec), Tokens), 73 with_output_to( 74 string(HTML), 75 print_html(current_output, Tokens)), 76 format('~w', [HTML]).

82html(Spec) --> 83 { make_safe_html(Spec, SafeSpec) }, 84 html_write:html(SafeSpec). 85 86make_safe_html(HTML0, HTML) :- 87 ( pengine_self(M) 88 -> true 89 ; prolog_load_context(module, M) 90 ), 91 make_safe_html(HTML0, M, HTML). 92 93make_safe_html(Var, M, M:html(Var)) :- 94 var(Var), 95 !. 96make_safe_html(Module:HTML0, M, Module:HTML) :- 97 !, 98 ( Module == M 99 -> true 100 ; permission_error(cross_module_call, M, Module:HTML) 101 ), 102 make_safe_html(HTML0, M, HTML). 103make_safe_html([], _, []) :- 104 !. 105make_safe_html([H0|T0], M, [H|T]) :- 106 !, 107 make_safe_html(H0, M, H), 108 make_safe_html(T0, M, T). 109make_safe_html(element(Name, Attrs0, Content0), M, 110 element(Name, Attrs, Content)) :- 111 !, 112 must_be(atom, Name), 113 safe_attrs(Attrs0, M, Attrs), 114 make_safe_html(Content0, M, Content). 115make_safe_html(Format-Args, _M, Format-Args) :- 116 !, 117 safe_goal(format(Format, Args)). 118make_safe_html(\Raw0, M, \Raw) :- 119 is_list(Raw0), 120 !, 121 make_safe_raw(Raw0, M, Raw). 122make_safe_html(\Goal, M, \Goal) :- 123 !, 124 must_be(callable, Goal), 125 dcg_extend(Goal, DcgGoal), 126 safe_goal(M:DcgGoal). 127make_safe_html(Elem0, M, Elem) :- 128 Elem0 =.. [Name, Attrs0, Content0], 129 !, 130 safe_attrs(Attrs0, M, Attrs), 131 make_safe_html(Content0, M, Content), 132 Elem =.. [Name, Attrs, Content]. 133make_safe_html(Elem0, M, Elem) :- 134 Elem0 =.. [Name, AttrsOrContent0], 135 !, 136 ( html_write:layout(Name, _, empty) 137 -> safe_attrs(AttrsOrContent0, M, Safe) 138 ; make_safe_html(AttrsOrContent0, M, Safe) 139 ), 140 Elem =.. [Name, Safe]. 141make_safe_html(Text, _, Text) :- 142 atomic(Text), 143 !. 144make_safe_html(Term, _, _) :- 145 domain_error(html_term, Term). 146 147safe_attrs([], _, []) :- 148 !. 149safe_attrs([H0|T0], M, [H|T]) :- 150 !, 151 safe_attrs(H0, M, H), 152 safe_attrs(T0, M, T). 153safe_attrs(Name=Value0, M, Name=Value) :- 154 !, 155 safe_attr_value(Value0, M, Value). 156safe_attrs(NameValue0, M, NameValue) :- 157 !, 158 NameValue0 =.. [Name,Value0], 159 safe_attr_value(M, Value0, Value), 160 NameValue =.. [Name,Value]. 161 162safe_attr_value(_, Value0, _) :- 163 var(Value0), 164 !, 165 instantiation_error(Value0). 166safe_attr_value(M, Value0, Value) :- 167 is_list(Value0), 168 !, 169 maplist(safe_attr_value(M), Value0, Value). 170safe_attr_value(_M, Format-Args, Format-Args) :- 171 !, 172 safe_goal(format(Format, Args)). 173safe_attr_value(M, A0+B0, A+B) :- 174 safe_attr_value(M, A0, A), 175 safe_attr_value(M, B0, B). 176safe_attr_value(_, V, V) :- 177 atomic(V).

183make_safe_raw(Raw0, _M, \safe_raw_html(Raw0)) :- 184 var(Raw0), 185 !. 186make_safe_raw([], _, []) :- 187 !. 188make_safe_raw([H0|T0], M, [H|T]) :- 189 !, 190 make_safe_raw(H0, M, H), 191 make_safe_raw(T0, M, T). 192make_safe_raw(Format-Args, _, Format-Args) :- 193 !, 194 safe_goal(format(Format, Args)). 195make_safe_raw(Atomic, _, Atomic) :- 196 atomic(Atomic), 197 !. 198make_safe_raw(\Goal, M, \Goal) :- 199 !, 200 must_be(callable, Goal), 201 dcg_extend(Goal, DcgGoal), 202 safe_goal(M:DcgGoal). 203make_safe_raw(Term, _, _) :- 204 domain_error(html_raw, Term).

210safe_raw_html(Raw0) :- 211 ( pengine_self(M) 212 -> true 213 ; prolog_load_context(module, M) 214 ), 215 make_safe_raw(Raw0, M, Raw), 216 html(\[Raw]). 217 218dcg_extend(Goal, DcgGoal) :- 219 must_be(callable, Goal), 220 Goal \= (_:_), 221 Goal =.. List, 222 append(List, [_,_], ExList), 223 DcgGoal =.. ExList. 224 225:- multifile sandbox:safe_primitive/1. 226 227sandbox:safe_meta_predicate(swish_html_output:html/1). 228sandbox:safe_meta_predicate(swish_html_output:html/3). 229sandbox:safe_meta_predicate(swish_html_output:safe_raw_html/1)