1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
|
function obj = jsonpath(root, jpath, varargin)
%
% obj=jsonpath(root, jpath)
%
% Query and retrieve elements from matlab data structures using JSONPath
%
% author: Qianqian Fang (q.fang <at> neu.edu)
%
% input:
% root: a matlab data structure like an array, cell, struct, etc
% jpath: a string in the format of JSONPath, see loadjson help
%
% output:
% obj: if the specified element exist, obj returns the result
%
% example:
% jsonpath(struct('a',[1,2,3]), '$.a[1]') % returns 2
%
% license:
% BSD or GPL version 3, see LICENSE_{BSD,GPLv3}.txt files for details
%
% -- this function is part of JSONLab toolbox (http://iso2mesh.sf.net/cgi-bin/index.cgi?jsonlab)
%
obj = root;
jpath = regexprep(jpath, '([^.\]])(\[[-0-9:\*]+\])', '$1.$2');
jpath = regexprep(jpath, '\[[''"]*([^\]''"]+)[''"]*\]', '.[$1]');
jpath = regexprep(jpath, '\\\.', '_0x2E_');
while (regexp(jpath, '(\[[''"]*[^\]''"]+)\.(?=[^\]''"]+[''"]*\])'))
jpath = regexprep(jpath, '(\[[''"]*[^\]''"]+)\.(?=[^\]''"]+[''"]*\])', '$1_0x2E_');
end
[pat, paths] = regexp(jpath, '(\.{0,2}[^\.]+)', 'match', 'tokens');
if (~isempty(pat) && ~isempty(paths))
if (strcmp(paths{1}, '$'))
paths(1) = [];
end
for i = 1:length(paths)
[obj, isfound] = getonelevel(obj, paths, i, varargin{:});
if (~isfound)
return
end
end
end
%% scan function
function [obj, isfound] = getonelevel(input, paths, pathid, varargin)
pathname = paths{pathid};
if (iscell(pathname))
pathname = pathname{1};
end
deepscan = ~isempty(regexp(pathname, '^\.\.', 'once'));
origpath = pathname;
pathname = regexprep(pathname, '^\.+', '');
if (strcmp(pathname, '$'))
obj = input;
elseif (regexp(pathname, '$\d+'))
obj = input(str2double(pathname(2:end)) + 1);
elseif (~isempty(regexp(pathname, '^\[[-0-9\*:]+\]$', 'once')) || iscell(input))
arraystr = pathname(2:end - 1);
if (find(arraystr == ':'))
arrayrange = regexp(arraystr, '(?<start>-*\d*):(?<end>-*\d*)', 'names');
if (~isempty(arrayrange.start))
arrayrange.start = str2double(arrayrange.start);
arrayrange.start = (arrayrange.start < 0) * length(input) + arrayrange.start + 1;
else
arrayrange.start = 1;
end
if (~isempty(arrayrange.end))
arrayrange.end = str2double(arrayrange.end);
arrayrange.end = (arrayrange.end < 0) * length(input) + arrayrange.end + 1;
else
arrayrange.end = length(input);
end
elseif (regexp(arraystr, '^[-0-9:]+', 'once'))
firstidx = str2double(arraystr);
if (firstidx < 0)
firstidx = length(input) + firstidx + 1;
else
firstidx = firstidx + 1;
end
arrayrange.start = firstidx;
arrayrange.end = firstidx;
elseif (~isempty(regexp(arraystr, '^\*', 'once')))
% do nothing
end
if (exist('arrayrange', 'var'))
obj = {input(arrayrange.start:arrayrange.end)};
else
arrayrange = struct('start', 1, 'end', length(input));
end
if (~exist('obj', 'var') && iscell(input))
input = {input{arrayrange.start:arrayrange.end}};
if (deepscan)
searchkey = ['..' pathname];
else
searchkey = origpath;
end
for idx = 1:length(input)
[val, isfound] = getonelevel(input{idx}, [paths{1:pathid - 1} {searchkey}], pathid);
if (isfound)
if (~exist('newobj', 'var'))
newobj = {};
end
newobj = [newobj(:)', val(:)'];
end
end
if (exist('newobj', 'var'))
obj = newobj;
end
if (exist('obj', 'var') && iscell(obj) && length(obj) == 1)
obj = obj{1};
end
else
obj = input(arrayrange.start:arrayrange.end);
end
elseif (isstruct(input) || isa(input, 'containers.Map') || isa(input, 'table'))
pathname = regexprep(pathname, '^\[(.*)\]$', '$1');
stpath = encodevarname(pathname);
if (isstruct(input))
if (isfield(input, stpath))
obj = {input.(stpath)};
end
elseif (isa(input, 'table'))
if (any(ismember(input.Properties.VariableNames, stpath)))
obj = {input.(stpath)};
end
else
if (isKey(input, pathname))
obj = {input(pathname)};
end
end
if (~exist('obj', 'var') || deepscan)
if (isa(input, 'containers.Map'))
items = keys(input);
else
items = fieldnames(input);
end
for idx = 1:length(items)
if (isa(input, 'containers.Map'))
[val, isfound] = getonelevel(input(items{idx}), [paths{1:pathid - 1} {['..' pathname]}], pathid);
elseif (isa(input, 'table'))
[val, isfound] = getonelevel({input.(items{idx})}, [paths{1:pathid - 1} {['..' pathname]}], pathid);
elseif (isstruct(input) && length(input) > 1) % struct array
[val, isfound] = getonelevel({input.(items{idx})}, [paths{1:pathid - 1} {['..' pathname]}], pathid);
else
[val, isfound] = getonelevel(input.(items{idx}), [paths{1:pathid - 1} {['..' pathname]}], pathid);
end
if (isfound)
if (~exist('obj', 'var'))
obj = {};
end
if (iscell(val))
obj = [obj(:)', val(:)'];
else
obj = [obj(:)', {val}];
end
end
end
if (exist('obj', 'var') && length(obj) == 1)
obj = obj{1};
end
end
if (exist('obj', 'var') && iscell(obj) && length(obj) == 1)
obj = obj{1};
end
elseif (~deepscan)
error('json path segment "%s" can not be found in the input object\n', pathname);
end
if (~exist('obj', 'var'))
isfound = false;
obj = [];
elseif (nargout > 1)
isfound = true;
end
|
