source: trunk/src/@xmltree/find.m @ 920

Last change on this file since 920 was 723, checked in by sommeria, 11 years ago

xmltree and toolbox_calib added to svn

File size: 5.0 KB
Line 
1function list = find(varargin)
2% XMLTREE/FIND Find elements in a tree with specified characteristics
3% FORMAT list = find(varargin)
4%
5% tree  - XMLTree object
6% xpath - string path with specific grammar (XPath)
7% uid   - lists of root uid's
8% parameter/value - pair of pattern
9% list  - list of uid's of matched elements
10%
11%      list = find(tree,xpath)
12%      list = find(tree,parameter,value[,parameter,value])
13%      list = find(tree,uid,parameter,value[,parameter,value])
14%
15% Grammar for addressing parts of an XML document:
16%        XML Path Language XPath (http://www.w3.org/TR/xpath)
17% Example: /element1//element2[1]/element3[5]/element4
18%_______________________________________________________________________
19%
20% Find elements in an XML tree with specified characteristics or given
21% a path (using a subset of XPath language).
22%_______________________________________________________________________
23% @(#)find.m                 Guillaume Flandin                 01/10/29
24
25% TODO:
26%   - clean up subroutines
27%   - find should only be documented using XPath (other use is internal)
28%   - handle '*', 'last()' in [] and '@'
29%   - if a key is invalid, should rather return [] than error ?
30
31if nargin==0
32        error('[XMLTree] A tree must be provided');
33elseif nargin==1
34        list = 1:length(tree.tree);
35        return
36elseif mod(nargin,2)
37        list = sub_find_subtree1(varargin{1}.tree,root(tree),varargin{2:end});
38elseif isa(varargin{2},'double') & ...
39           ndims(varargin{2}) == 2 & ...
40           min(size(varargin{2})) == 1
41        list = unique(sub_find_subtree1(varargin{1}.tree,varargin{2:end}));
42elseif nargin==2 & ischar(varargin{2})
43        list = sub_pathfinder(varargin{:});
44else
45   error('[XMLTree] Arguments must be parameter/value pairs.');
46end
47
48%=======================================================================
49function list = sub_find_subtree1(varargin)
50        list = [];
51        for i=1:length(varargin{2})
52                res = sub_find_subtree2(varargin{1},...
53                                varargin{2}(i),varargin{3:end});
54                list = [list res];
55        end
56
57%=======================================================================
58function list = sub_find_subtree2(varargin)
59        uid = varargin{2};
60        list = [];
61        if sub_comp_element(varargin{1}{uid},varargin{3:end})
62                list = [list varargin{1}{uid}.uid];
63        end
64        if isfield(varargin{1}{uid},'contents')
65                list = [list sub_find_subtree1(varargin{1},...
66                        varargin{1}{uid}.contents,varargin{3:end})];
67        end
68
69%=======================================================================
70function match = sub_comp_element(varargin)
71match = 0;
72try,
73        % v = getfield(varargin{1}, varargin{2}); % slow...
74        for i=1:floor(nargin/2)
75                v = subsref(varargin{1}, struct('type','.','subs',varargin{i+1}));     
76                if strcmp(v,varargin{i+2})
77                        match = 1;
78                end
79        end
80catch,
81end
82
83% More powerful but much slower
84%match = 0;
85%for i=1:length(floor(nargin/2)) % bug: remove length !!!
86%   if isfield(varargin{1},varargin{i+1})
87%         if ischar(getfield(varargin{1},varargin{i+1})) & ischar(varargin{i+2})
88%          if strcmp(getfield(varargin{1},varargin{i+1}),char(varargin{i+2}))
89%                       match = 1;
90%                end
91%         elseif isa(getfield(varargin{1},varargin{i+1}),'double') & ...
92%                       isa(varargin{i+2},'double')
93%                if getfield(varargin{1},varargin{i+1}) == varargin{i+2}
94%                       match = 1;
95%               end
96%        else
97%               warning('Cannot compare different objects');
98%         end
99%   end
100%end
101
102%=======================================================================
103function list = sub_pathfinder(tree,pth)
104        %- Search for the delimiter '/' in the path
105        i = findstr(pth,'/');
106        %- Begin search by root
107        list = root(tree);
108        %- Walk through the tree
109        j = 1;
110        while j <= length(i)
111                %- Look for recursion '//'
112                if j<length(i) & i(j+1)==i(j)+1
113                        recursive = 1;
114                        j = j + 1;
115                else
116                        recursive = 0;
117                end
118                %- Catch the current tag 'element[x]'
119                if j ~= length(i)
120                        element = pth(i(j)+1:i(j+1)-1);
121                else
122                        element = pth(i(j)+1:end);
123                end
124                %- Search for [] brackets
125                k = xml_findstr(element,'[',1,1);
126                %- If brackets are present in current element
127                if ~isempty(k)
128                        l   = xml_findstr(element,']',1,1);
129                        val = str2num(element(k+1:l-1));
130                        element = element(1:k-1);
131                end
132                %- Use recursivity
133                if recursive
134                        list = find(tree,list,'name',element);
135                %- Just look at children
136                else
137                        if i(j)==1 % if '/root/...' (list = root(tree) in that case)
138                                if sub_comp_element(tree.tree{list},'name',element)
139                                        % list = 1; % list still contains root(tree)
140                                else
141                                        list = [];
142                                        return;
143                                end
144                        else
145                                list = sub_findchild(tree,list,element);
146                        end
147                end
148                % If an element is specified using a key
149                if ~isempty(k)
150                        if val < 1 | val > length(list)+1
151                                error('[XMLTree] Bad key in the path.');
152                        elseif val == length(list)+1
153                                list = [];
154                                return;
155                        end
156                        list = list(val);
157                end
158                if isempty(list), return; end
159                j = j + 1;
160        end
161       
162%=======================================================================
163function list = sub_findchild(tree,listt,elmt)
164        list = [];
165        for a=1:length(listt)
166                for b=1:length(tree.tree{listt(a)}.contents)
167                        if sub_comp_element(tree.tree{tree.tree{listt(a)}.contents(b)},'name',elmt)
168                                list = [list tree.tree{tree.tree{listt(a)}.contents(b)}.uid];
169                        end
170                end
171        end
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