1		% (c) 2021-2026 Lehrstuhl fuer Softwaretechnik und Programmiersprachen,
2		% Heinrich Heine Universitaet Duesseldorf
3		% This software is licenced under EPL 1.0 (http://www.eclipse.org/org/documents/epl-v10.html)
4
5		:- module(tools_json,
6		[get_json_key_object/3,
7		get_json_key_list/3,
8		get_json_attribute/3,
9		get_json_attribute_with_pos/5,
10		get_optional_json_attribute_with_pos/6,
11		get_optional_json_string_attribute_with_pos/6, extract_json_string/4,
12		get_optional_json_strings_attribute_with_pos/6,
13		get_optional_json_number_attribute_with_pos/6,
14		get_optional_json_array_attribute_with_pos/6,
15		is_json_equality_attr/3,
16		is_json_equality_attr_with_pos/5
17		]).
18
19		:- use_module(module_information).
20
21		:- module_info(group,infrastructure).
22		:- module_info(description,'A few utilities for JSON terms.').
23		% terms created e.g. by
24		% :- use_module(extrasrc(json_parser),[json_parse_file/3]).
25		% json_parse_file(FileName,Term,[rest(_),position_infos(true),strings_as_atoms(false)]),
26
27		% TODO: include/merge with VisB utils like get_attr_with_pos, del_attr_with_pos
28		:- use_module(error_manager).
29		:- use_module(library(lists)).
30
31		get_json_key_object(Key,JSON,Object) :- Key = [_|_],!,
32		add_internal_error('Illegal Key: ',get_json_key_object(Key,JSON,Object)),fail.
33		get_json_key_object(Key,JSON,Object) :-
34	?	get_json_attribute(Key,JSON,JObject),
35		JObject \= @(null),
36		(JObject = json(Object) -> true
37		; add_internal_error('Illegal JSON object for key:',Key:JObject),
38		fail
39		).
40
41		get_json_key_list(Key,JSON,Object) :- Key = [_|_],!,
42		add_internal_error('Illegal Key: ',get_json_key_list(Key,JSON,Object)),fail.
43		get_json_key_list(Key,JSON,List) :-
44	?	get_json_attribute(Key,JSON,JList),
45		JList \= @(null),
46		(JList = array(List) -> true
47		; add_internal_error('Illegal JSON list for key:',Key:JList),
48		fail
49		).
50
51
52	?	get_json_attribute(Attr,ObjList,Value) :- member(Equality,ObjList),
53		is_json_equality_attr(Equality,Attr,Value).
54
55		get_json_attribute_with_pos(Attr,ObjList,File,Value,Pos) :-
56	?	member(Equality,ObjList),
57		is_json_equality_attr_with_pos(Equality,File,Attr,Value,Pos).
58
59		get_optional_json_attribute_with_pos(Attr,File,Value,Pos,ObjList,RemainingObjList) :-
60	?	select(Equality,ObjList,RemainingObjList),
61		is_json_equality_attr_with_pos(Equality,File,Attr,V,P),!,
62		Value=V, Pos=P.
63		get_optional_json_attribute_with_pos(_,_,@(null),unknown,AttrList,AttrList).
64
65
66		get_optional_json_string_attribute_with_pos(Attr,File,StringValue,Pos,ObjList,RemObjList) :-
67		get_optional_json_attribute_with_pos(Attr,File,Value,Pos,ObjList,RemObjList),
68		extract_json_string(Value,Attr,Pos,StringValue).
69
70		extract_json_string(string(S),_,_,Res) :- !, Res=S.
71		extract_json_string(@(null),_,_,Res) :- !, Res = @(null).
72		extract_json_string(Obj,Attr,Pos,_) :-
73		add_error(simb,'Illegal JSON string value for attribute: ',Attr,Pos),
74		write(Obj),nl,
75		fail.
76
77		% an array of strings or a single string returned as list
78		get_optional_json_strings_attribute_with_pos(Attr,File,StringValue,Pos,ObjList,RemObjList) :-
79		get_optional_json_attribute_with_pos(Attr,File,Value,Pos,ObjList,RemObjList),
80		extract_json_strings(Value,Attr,Pos,StringValue).
81
82		extract_json_strings(string(S),_,_,Res) :- !, Res=[S].
83		extract_json_strings(@(null),_,_,Res) :- !, Res = [].
84		extract_json_strings(array(A),Attr,Pos,Res) :- !,
85		findall(V,(member(AA,A), extract_json_string(AA,Attr,Pos,V)),Res).
86		extract_json_strings(Obj,Attr,Pos,_) :-
87		add_error(simb,'Illegal JSON string or string array value for attribute: ',Attr,Pos),
88		write(Obj),nl,
89		fail.
90
91
92		get_optional_json_array_attribute_with_pos(Attr,File,ArrayList,Pos,ObjList,RemObjList) :-
93		get_optional_json_attribute_with_pos(Attr,File,Value,Pos,ObjList,RemObjList),
94		extract_json_array(Value,ArrayList).
95
96		extract_json_array(@(null),Res) :- !, Res = [].
97		extract_json_array(array(A),Res) :- !, Res = A.
98		extract_json_array(Obj,Res) :- !, Res=[Obj].
99
100
101		get_optional_json_number_attribute_with_pos(Attr,File,NrValue,Pos,ObjList,RemObjList) :-
102		get_optional_json_attribute_with_pos(Attr,File,Value,Pos,ObjList,RemObjList),
103		extract_json_number(Value,Attr,Pos,NrValue).
104
105		extract_json_number(number(S),_,_,Res) :- !, Res=S.
106		extract_json_number(@(null),_,_,Res) :- !, Res = @(null).
107		extract_json_number(Obj,Attr,Pos,_) :-
108		add_error(simb,'Illegal JSON number value for attribute: ',Attr,Pos),
109		write(Obj),nl,
110		fail.
111
112
113		is_json_equality_attr('='(Attr,Val),Attr,Val).
114		is_json_equality_attr('='(Attr,Val,_Pos),Attr,Val). % we have position infos
115
116		is_json_equality_attr_with_pos('='(Attr,Val),_File,Attr,Val,unknown).
117		is_json_equality_attr_with_pos('='(Attr,Val,JPos),File,Attr,Val,ProBPos) :- create_position(JPos,File,ProBPos).
118
119		create_position(From-To,File,ProBPos) :-
120		ProBPos=src_position_with_filename_and_ec(From,1,To,1,File).