loadxml.m

function varargout = loadxml(filename,varargin)
%LOADXML Load workspace variables from disk (XML file).
%  LOADXML FILENAME retrieves all variables from a file given a full 
%  pathname or a MATLABPATH relative partial pathname (see PARTIALPATH).
%  If FILENAME has no extension LOAD looks for FILENAME and FILENAME.xml 
%  and treats it as an XML file. 
%  
%  LOAD, by itself, uses the XML file named 'matlab.xml'. It is an error
%  if 'matlab.xml' is not found.
%
%  LOAD FILENAME X loads only X.
%  LOAD FILENAME X Y Z ... loads just the specified variables.  The
%  wildcard '*' loads variables that match a pattern.
%  Requested variables from FILENAME are created in the workspace.
%
%  S = LOAD(...) returns the contents of FILENAME in variable S. S is
%  a struct containing fields matching the variables retrieved.
%  
%  Use the functional form of LOAD, such as LOAD('filename'), when the
%  file name is stored in a string, when an output argument is requested,
%  or if FILENAME contains spaces.
%
%  See also LOAD, XML2MAT, XMLTREE.

%  Copyright 2003 Guillaume Flandin. 
%  $Revision: 112 $  $Date: 2003/07/10 13:50 $

%  $Id: loadxml.m 112 2005-05-04 18:20:52Z john $

if nargin == 0
	filename = 'matlab.xml';
	fprintf('\nLoading from: %s\n\n',filename);
end

if ~ischar(filename)
	error('[LOADXML] Argument must contain a string.');
end

if ~exist(filename,'file')
	filename = [filename '.xml'];
	if ~exist(filename,'file')
		error(sprintf(...
		'[LOADXML] Unable to read file %s: file does not exist',filename));
	end
end

if nargout > 1,
	error('[LOADXML] Too many output arguments.');
end

t = xmltree(filename);

uid = children(t,root(t));

if nargout == 1
	% varargout{1} = struct([]); % Matlab 6.0 and above
end

flagfirstvar = 1;
for i=1:length(uid)
	if strcmp(get(t,uid(i),'type'),'element')
		vname = get(t,uid(i),'name');
		% TODO % No need to parse the whole tree 
		if isempty(varargin) | ismember(varargin,vname)
			v = xml_create_var(t,uid(i));
			if nargout == 1
				if flagfirstvar
					varargout{1} = struct(vname,v);
					flagfirstvar = 0;
				else
					varargout{1} = setfield(varargout{1},vname,v);
				end
			else
				assignin('caller',vname,v);
			end
		end
	end
end

%=======================================================================
function v = xml_create_var(t,uid)
	type = attributes(t,'get',uid,'type');
	sz   = str2num(attributes(t,'get',uid,'size'));
	
	switch type
		case 'double'
			v = str2num(get(t,children(t,uid),'value'));
			if ~isempty(sz)
				v = reshape(v,sz);
			end
		case 'sparse'
			u = children(t,uid);
			for k=1:length(u)
				if strcmp(get(t,u(k),'name'),'row')
					i = str2num(get(t,children(t,u(k)),'value'));
				elseif strcmp(get(t,u(k),'name'),'col')
					j = str2num(get(t,children(t,u(k)),'value'));
				elseif strcmp(get(t,u(k),'name'),'val')
					s = str2num(get(t,children(t,u(k)),'value'));
				end 
			end
		   v = sparse(i,j,s,sz(1),sz(2));
		case 'struct'
			u = children(t,uid);
			v = []; % works with Matlab < 6.0
			for i=1:length(u)
				s(1).type = '()';
				s(1).subs = {str2num(attributes(t,'get',u(i),'index'))};
				s(2).type = '.';
				s(2).subs = get(t,u(i),'name');
				v = subsasgn(v,s,xml_create_var(t,u(i)));
			end
			if isempty(u),
				v = struct([]); % Need Matlab 6.0 and above
			end
		case 'cell'
			v = cell(sz);
			u = children(t,uid);
			for i=1:length(u)
				v{str2num(attributes(t,'get',u(i),'index'))} = ...
					xml_create_var(t,u(i));
			end
		case 'char'
			if isempty(children(t,uid))	
				v = '';
			else
				v = get(t,children(t,uid),'value');
			end
		case  {'int8','uint8','int16','uint16','int32','uint32'}
			% TODO % Handle integer formats
			warning(sprintf('%s matrices not handled.',type));
			v = 0;
		otherwise
			try,
				v = feval(class(v),get(t,uid,'value'));
			catch,
				warning(sprintf(...
				'[LOADXML] Cannot convert from XML to %s.',type));
			end
	end