function s = convert(tree,uid)
% XMLTREE/CONVERT Converter an XML tree in a Matlab structure
% 
% tree      - XMLTree object
% uid       - uid of the root of the subtree, if provided.
%             Default is root
% s         - converted structure
%_______________________________________________________________________
%
% Convert an xmltree into a Matlab structure, when possible.
% When several identical tags are present, a cell array is used.
% The root tag is not saved in the structure.
% If provided, only the structure corresponding to the subtree defined
% by the uid UID is returned.
%_______________________________________________________________________
% @(#)convert.m                 Guillaume Flandin              02/04/11

% Exemple:
% tree: <toto><titi>field1</titi><tutu>field2</tutu><titi>field3</titi></toto>
% toto = convert(tree);
% <=> toto = struct('titi',{{'field1', 'field3'}},'tutu','field2')

error(nargchk(1,2,nargin));

% Get the root uid of the output structure
if nargin == 1
	% Get the root uid of the XML tree
	root_uid = root(tree);
else
	% Uid provided by user
	root_uid = uid;
end

% Initialize the output structure
% struct([]) should be used but this only works with Matlab 6
% So we create a field that we delete at the end
%s = struct(get(tree,root_uid,'name'),''); % struct([])
s = struct('deletedummy','');

%s = sub_convert(tree,s,root_uid,{get(tree,root_uid,'name')});
s = sub_convert(tree,s,root_uid,{});

s = rmfield(s,'deletedummy');

%=======================================================================
function s = sub_convert(tree,s,uid,arg)
	type = get(tree,uid,'type');
	switch type
		case 'element'
			child = children(tree,uid);
			l = {};
			ll = {};
			for i=1:length(child)
				if isfield(tree,child(i),'name')
					ll = { ll{:}, get(tree,child(i),'name') };
				end
			end
			for i=1:length(child)
				if isfield(tree,child(i),'name')
					name = get(tree,child(i),'name');
					nboccur = sum(ismember(l,name));
					nboccur2 = sum(ismember(ll,name));
					l = { l{:}, name };
					if nboccur | (nboccur2>1)
						arg2 = { arg{:}, name, {nboccur+1} };
					else
						arg2 = { arg{:}, name};
					end
				else
					arg2 = arg;
				end
				s = sub_convert(tree,s,child(i),arg2);
			end
			if isempty(child)
				s = sub_setfield(s,arg{:},'');
			end
		case 'chardata'
			s = sub_setfield(s,arg{:},get(tree,uid,'value'));
		case 'cdata'
			s = sub_setfield(s,arg{:},get(tree,uid,'value'));
		case 'pi'
			% Processing instructions are evaluated if possible
			app = get(tree,uid,'target');
			switch app
				case {'matlab',''}
					s = sub_setfield(s,arg{:},eval(get(tree,uid,'value')));
				case 'unix'
					s = sub_setfield(s,arg{:},unix(get(tree,uid,'value')));
				case 'dos'
					s = sub_setfield(s,arg{:},dos(get(tree,uid,'value')));
				case 'system'
					s = sub_setfield(s,arg{:},system(get(tree,uid,'value')));
				otherwise
					try,
						s = sub_setfield(s,arg{:},feval(app,get(tree,uid,'value')));
					catch,
						warning('[Xmltree/convert] Unknown target application');
					end
			end
		case 'comment'
			% Comments are forgotten
		otherwise
			warning(sprintf('Type %s unknown : not saved',get(tree,uid,'type')));
	end
	
%=======================================================================
function s = sub_setfield(s,varargin)
% Same as setfield but using '{}' rather than '()'
%if (isempty(varargin) | length(varargin) < 2)
%    error('Not enough input arguments.');
%end

subs = varargin(1:end-1);
for i = 1:length(varargin)-1
    if (isa(varargin{i}, 'cell'))
        types{i} = '{}';
    elseif isstr(varargin{i})
        types{i} = '.';
        subs{i} = varargin{i}; %strrep(varargin{i},' ',''); % deblank field name
    else
        error('Inputs must be either cell arrays or strings.');
    end
end

% Perform assignment
try
   s = builtin('subsasgn', s, struct('type',types,'subs',subs), varargin{end});
catch
   error(lasterr)
end