1/* Part of SWISH 2 3 Author: Jan Wielemaker 4 E-mail: J.Wielemaker@vu.nl 5 WWW: http://www.swi-prolog.org 6 Copyright (c) 2016, VU University 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(swish_csv, []). 36:- use_module(library(pengines), []). 37:- use_module(library(pairs)). 38:- use_module(library(csv), [csv_write_stream/3]). 39:- use_module(library(apply)). 40:- use_module(library(pprint)). 41:- use_module(library(option)). 42:- use_module(library(http/http_cors)).

Support CSV output from a Pengines server

This module defines the result-format csv for Pengines. It allows SWISH users to post a query against the core Prolog system or a saved SWISH program and obtain the results using a simple web client such as curl. An example shell script is provided in client/swish-ask.sh.

To be done: - Provide streaming output */

64pengines:write_result(csv, Event, OptionDict) :- 65 ( Disposition = OptionDict.get(disposition) 66 -> Options = [disposition(Disposition)] 67 ; Options = [] 68 ), 69 csv(Event, Options). 70 71csv(create(_Id, Features), Options) :- !, 72 memberchk(answer(Answer), Features), 73 csv(Answer, Options). 74csv(destroy(_Id, Wrapped), Options) :- !, 75 csv(Wrapped, Options). 76csv(success(_Id, Answers, Projection, _Time, More), Options) :- !, 77 VarTerm =.. [row|Projection], 78 success(Answers, VarTerm, [more(More)|Options]). 79csv(error(_Id, Error), _Options) :- !, 80 message_to_string(Error, Msg), 81 format('Status: 400 Bad request~n'), 82 format('Content-type: text/plain~n~n'), 83 format('ERROR: ~w~n', [Msg]). 84csv(output(_Id, message(_Term, _Class, HTML, _Where)), _Opts) :- !, 85 format('Status: 400 Bad request~n'), 86 format('Content-type: text/html~n~n'), 87 format('<html>~n~s~n</html>~n', [HTML]). 88csv(page(Page, Event), Options) :- 89 csv(Event, [page(Page)|Options]). 90csv(failure(_Id, _Time), Options) :- !, 91 success([], -, [more(false)|Options]). 92csv(Event, _) :- 93 print_term(Event, [output(user_error)]). 94 95success(Answers, VarTerm, Options) :- 96 write_answers(Answers, VarTerm, Options), !. 97success(Answers, VarTerm, Options) :- 98 write_answers(Answers, VarTerm), !, 99 assertion(\+option(page(_), Options)). 100success(Answers, _VarTerm, Options) :- 101 option(page(Page), Options), 102 Page > 1, !, 103 maplist(csv_answer, Answers, Rows), 104 forall(paginate(100, OutPage, Rows), 105 csv_write_stream(current_output, OutPage, [])). 106success(Answers, VarTerm, Options) :- 107 option(disposition(Disposition), Options, 'swish-result.csv'), 108 maplist(csv_answer, Answers, Rows), 109 cors_enable, 110 format('Content-encoding: chunked~n'), 111 format('Content-disposition: attachment; filename="~w"~n', [Disposition]), 112 format('Content-type: text/csv~n~n'), 113 projection_row(VarTerm), 114 forall(paginate(100, Page, Rows), 115 csv_write_stream(current_output, Page, [])). 116 117projection_row(-) :- !. 118projection_row(row) :- !. 119projection_row(VarTerm) :- 120 csv_write_stream(current_output, [VarTerm], []). 121 122paginate(Len, Page, List) :- 123 length(Page0, Len), 124 ( append(Page0, Rest, List) 125 -> ( Page = Page0 126 ; paginate(Len, Page, Rest) 127 ) 128 ; Page = List 129 ). 130 131 132csv_answer(JSON, Row) :- 133 is_dict(JSON), !, 134 dict_pairs(JSON, _, Pairs), 135 pairs_values(Pairs, Values), 136 maplist(csv_value, Values, CVSValues), 137 Row =.. [row|CVSValues]. 138csv_answer(RowIn, Row) :- 139 compound(RowIn), !, 140 RowIn =.. [_|Values], 141 maplist(csv_value, Values, CVSValues), 142 Row =.. [row|CVSValues]. 143 144csv_value(Var, '') :- 145 var(Var), !. 146csv_value(Number, Number) :- 147 number(Number), !. 148csv_value(Atom, Atom) :- 149 atom(Atom), !. 150csv_value(String, String) :- 151 string(String), !. 152csv_value(Term, Value) :- 153 term_string(Term, Value)