function S = XMLPlistToStruct(xml)
% XMLPlistToStruct Parse Mac OSX XML property list into matlab structure
%
% S = XMLPlistToStruct(xmlText)
%
% return structure S from OS X style XML property list in string xmlText
%
% The mapping is straightforward:
% dict -> structure
% array -> cell array
% property list keys become field names
% (note: keys may only contain alphanumeric or space chars)
% integer, real -> double
% string, data, date -> string
%
% Note: data and date are treated as strings, with a suffix (_DATA or
% _DATE) added to the field name indicating the original type,
% similarly _INTEGER is added for integers. This ensures
% that the original type is preserved if we convert the
% structure back to XML.
%
% See the example plist and usage at the end of this file
%
% Details of XML property list format are found at:
% http://developer.apple.com/documentation/Cocoa/Conceptual/PropertyLists/Concepts/XMLPListsConcept.html
% http://www.apple.com/DTDs/PropertyList-1.0.dtd
%
% JRI 3/14/05 (John R. Iversen <iversen@nsi.edu>)
dictLevel = 0;
inArray = 0;
arrayIndex = 0;
key = {};
ibra = findstr(xml,'<');
iket = findstr(xml,'>');
if (length(ibra) ~= length(iket)),
error('unmatched brackets')
end
itag = 1;
while (itag <= length(ibra)),
value = [];
valueStr = '';
keySuffix = '';
tag = xml( (ibra(itag)+1):(iket(itag)-1) );
%split tag on first space into tag proper and additional information
iSpace = strfind(tag, ' ');
if ~isempty(iSpace),
tagInfo = tag( (iSpace(1)+1):end );
tag = tag(1:(iSpace(1)-1));
end
%if we're in an array, increase the index by one
if (dictLevel > 0) & inArray(dictLevel),
arrayIndex(dictLevel) = arrayIndex(dictLevel) + 1;
end
switch tag,
case '!DOCTYPE', %make sure it's a plist
if isempty(findstr(tagInfo, 'plist')),
error('This is not an Apple plist')
end
case {'?xml', 'plist', '/plist'},
%skip other header tags--assume they, as well as outer <plist></plist>, are correct
case 'dict',
dictLevel = dictLevel + 1;
inArray(dictLevel) = 0;
case '/dict',
key(dictLevel) = [];
if (inArray(dictLevel) ~= 0), error('Array not closed by end of dict'); end
dictLevel = dictLevel - 1;
case 'key',
key{dictLevel} = strrep(xml( (iket(itag)+1):(ibra(itag+1)-1) ), ' ', '_');%space->_
itag = itag + 1; %skip to close
ctag = xml( (ibra(itag)+1):(iket(itag)-1) );
if ~strcmp(ctag, ['/' tag]), error(['<' tag '> not properly closed']); end
case 'array',
inArray(dictLevel) = 1;
arrayIndex(dictLevel) = 0;
case '/array',
inArray(dictLevel) = 0;
arrayIndex(dictLevel) = 0;
case 'array/', %empty array
value = { [] };
case 'true/'
value = true; %logical
case 'false/'
value = false; %logical
case {'string', 'date', 'data'},
valueStr = xml( (iket(itag)+1):(ibra(itag+1)-1) );
itag = itag + 1; %skip to close
closetag = xml( (ibra(itag)+1):(iket(itag)-1) );
if ~strcmp(closetag, ['/' tag]), error(['<' tag '> not properly closed']); end
%add suffix to indicate original type
if strcmp(tag, 'date') | strcmp(tag, 'data'),
keySuffix = ['__' upper(tag)];
end
case {'integer', 'real'}
valueStr = xml( (iket(itag)+1):(ibra(itag+1)-1) );
value = str2num(valueStr);
itag = itag + 1; %skip to close
closetag = xml( (ibra(itag)+1):(iket(itag)-1) );
if ~strcmp(closetag, ['/' tag]), error(['<' tag '> not properly closed']); end
%add suffix to indicate original type
if strcmp(tag, 'integer'),
keySuffix = ['__' upper(tag)];
end
otherwise
error(['Unexpected tag: ' tag])
end
if (dictLevel > 0 & length(key)==dictLevel), %if we have the key for current dictLevel
if ~isempty(value) | ~isempty(valueStr),
%construct the field name hierarchy, including advancing the array indexing
fieldname = '';
for ifield = 1:dictLevel,
fieldname = [fieldname '.' key{ifield}];
if inArray(ifield),
fieldname = [fieldname '{' num2str(arrayIndex(ifield)) '}'];
end
end
%store value, if we have one
if ~isempty(value), %it's numeric
cmd = ['S' fieldname keySuffix ' = value ;'];
eval(cmd);
elseif ~isempty(valueStr), %it's string
cmd = ['S' fieldname keySuffix ' = valueStr ;'];
eval(cmd);
end
end
end
itag = itag+1;
end
if (dictLevel > 0) | any(inArray),
error('unfinished dict or array, but now at end of file')
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%example plist
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% <?xml version="1.0" encoding="UTF-8"?>
% <!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
% <plist version="1.0">
% <dict>
% <key>string</key>
% <string>aString</string>
% <key>int</key>
% <integer>123</integer>
% <key>double</key>
% <real>123.456</real>
% <key>true</key>
% <true/>
% <key>false</key>
% <false/>
% <key>stringarray</key>
% <array>
% <string>string 1</string>
% <string>string 2</string>
% </array>
% <key>subDict</key>
% <dict>
% <key>nodes</key>
% <integer>6</integer>
% <key>channels</key>
% <integer>2</integer>
% </dict>
% <key>arrayofdict</key>
% <array>
% <dict>
% <key>nodes</key>
% <integer>6</integer>
% <key>channels</key>
% <integer>2</integer>
% </dict>
% <dict>
% <key>nodes</key>
% <integer>6</integer>
% <key>channels</key>
% <integer>2</integer>
% </dict>
% </array>
% <key>emptyArray</key>
% <array/>
% <key>aDate</key>
% <date>2005-03-15T07:08:06Z</date>
% <key>someData</key>
% <data>ZDI5eWF5Qm1iM0lnY0dWaFkyVT0=</data>
% </dict>
% </plist>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%example usage
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% >>S = XMLPlistToStruct(xmlString)
%
% S =
%
% string: 'aString'
% int__INTEGER: 123
% double: 123.46
% true: 1
% false: 0
% stringarray: {'string 1' 'string 2'}
% subDict: [1x1 struct]
% arrayofdict: {[1x1 struct] [1x1 struct]}
% emptyArray: {[]}
% aDate__DATE: '2005-03-15T07:08:06Z'
% someData__DATA: 'ZDI5eWF5Qm1iM0lnY0dWaFkyVT0='
%
% >> S.arrayofdict{1}.nodes
%
% ans =
%
% 6
%
% >> xml = structToXMLPlist(S);
