Refactor, add skeleton for extra code conversion

The XML processing code has been split into individual components and
wrapped for better portability in the code. No change to functionality
has been made.

Framework has been added to support additional conversion parameters.

Inline documentation updated with new syntax.

See: #6

Author: sco1

mlapp2classdef.m

@@ -1,4 +1,4 @@
-function mlapp2classdef(pathToMLapp)
+function mlapp2classdef(pathToMLapp, varargin)
 % MLAPP2CLASSDEF converts an App Designer GUI's class definition, packaged 
 % as a *.mlapp file, from XML to a standalone *.m class definition.
 %
@@ -9,6 +9,12 @@ function mlapp2classdef(pathToMLapp)
 % pathToMLapp can be a string for a single file or a cell array of strings
 % for multiple files. Filepaths should be absolute.
 %
+% MLAPP2CLASSDEF(..., 'ReplaceAppUI', flag) replaces App Designer UI
+% elements with their "regular" MATLAB equivalents (e.g. App Designer uses
+% UIFIGURE where MATLAB uses FIGURE). flag is a boolean value, the default
+% is false. To prompt the user to select an app file with this syntax, pass
+% an empty first argument (e.g. MLAPP2CLASSDEF([], 'ReplaceAppUI', True)).
+%
 % The class definition for an App Designer GUI is embedded in an XML file
 % located in a subfolder of the packaged *.mlapp file, which can be
 % accessed like a *.zip file. MLAPP2CLASSDEF strips the XML header & footer
@@ -25,13 +31,17 @@ function mlapp2classdef(pathToMLapp)
 end
 
 % Choose appropriate behavior based on number of inputs
-if nargin == 0
+if nargin == 0 || ~exist('pathToMLapp', 'var') || isempty(pathToMLapp)
     % No input selected, prompt user to select a MATLAB app to process
     % Currently limited to single file selection
-    [filename, pathname] = uigetfile('*.mlapp', 'Select MATLAB App');
+    [filename, pathname] = uigetfile('*.mlapp', 'Select MATLAB App', 'MultiSelect', 'on');
+    pathToMLapp = fullfile(pathname, filename);
     if ~filename
         error('mlapp2classdef:NoFileSelected', 'No file selected, exiting...');
     else
+        % uigetfile's multiselect doesn't currently allow to select files
+        % in different directories, so we can inherit the pathname(s) from
+        % the uigetfile call.
         [~, appname, ext] = fileparts(filename);
     end
 else
@@ -48,63 +58,27 @@ function mlapp2classdef(pathToMLapp)
     filename = strcat(appname, ext);
 end
 
+% Check varargin for optional processing flags
+% Placeholder logic to be replaced by inputparser instance
+if isempty(varargin)
+    uielementflag = false;
+else
+    uielementflag = false;
+end
+
 if iscell(pathToMLapp)
     for indF = 1:numel(pathToMLapp)
         checkfile(pathname{indF}, filename{indF}, ext{indF});
-        processMlapp(pathname{indF}, filename{indF}, appname{indF});
+        processapp(pathname{indF}, filename{indF}, appname{indF}, uielementflag)
         % TODO: Add a counter of successfully converted files.
     end
 else
     checkfile(pathname, filename, ext);
-    processMlapp(pathname, filename, appname);
+    processapp(pathname, filename, appname, uielementflag)
 end
 
 end
 
-function processMlapp(pathname, filename, appname)
-% Unzip user selected MATLAB App, which are packaged in a renamed zip file
-tmpdir = fullfile(pathname, sprintf('%s_tmp', appname));
-unzip(fullfile(pathname, filename), tmpdir);
-
-% Read in XML file
-% Since there isn't really much XML-ness to this XML file, no need to
-% utilize a full-fledged parser. MATLAB's won't open it anyway...
-xmlfile = fullfile(tmpdir, 'matlab', 'document.xml');
-
-% Get a count of lines in the xml file to preallocate the cell array in
-% memory. If no count can be made, revert to growing the array in memory
-nlines = countlines(xmlfile);
-if ~isempty(nlines)
-    A = cell(nlines, 1);
-else
-    A = {};
-end
-
-% Read XML file line-by-line into a cell array to make later export simpler
-fID = fopen(xmlfile, 'r');
-ii = 1;
-while ~feof(fID)
-    A{ii} = fgetl(fID);
-    ii = ii + 1;
-end
-fclose(fID);
-
-% Strip out header & footer, then save to a *.m file
-% Limit search to first & last lines of file, currently all that is
-% modified by MATLAB to wrap the class definition in XML
-A([1,end]) = regexprep(A([1,end]), '(^.*)\[(?=classdef)|(?<=end)(\].*$)', '');
-
-fID = fopen(fullfile(pathname, sprintf('%s.m', appname)), 'w');
-for ii = 1:length(A)
-    fprintf(fID, '%s\n', A{ii});
-end
-fclose(fID);
-
-rmdir(tmpdir, 's');
-
-disp(['Successfully unpacked ' filename '!']);
-end
-
 
 function A = validateattributes_wrapped(A, classes, attributes)
 % Wrap validateattributes with try-catch block for more verbose error
@@ -152,6 +126,74 @@ function checkfile(pathname, filename, ext)
 end
 
 
+function processapp(pathname, filename, appname, uielementflag)
+tmpdir = unpackapp(pathname, filename, appname);
+rawXML = loadXML(tmpdir);
+mymcode = stripXML(rawXML);
+
+if uielementflag
+    % Convert App Designer UI elements to "regular" MATLAB UI elements
+end
+
+writemfile(mymcode, pathname, appname);
+rmdir(tmpdir, 's');
+disp(['Successfully converted ' filename '!']);
+end
+
+
+function [tmpdir] = unpackapp(pathname, filename, appname)
+% Unzip user selected MATLAB App, which are packaged in a renamed zip file
+tmpdir = fullfile(pathname, sprintf('%s_tmp', appname));
+unzip(fullfile(pathname, filename), tmpdir);
+end
+
+
+function [rawXML] = loadXML(tmpdir)
+% Read in XML file
+% Since there isn't really much XML-ness to this XML file, no need to
+% utilize a full-fledged parser. MATLAB's won't open it anyway...
+xmlfile = fullfile(tmpdir, 'matlab', 'document.xml');
+
+% Get a count of lines in the xml file to preallocate the cell array in
+% memory. If no count can be made, revert to growing the array in memory
+nlines = countlines(xmlfile);
+if ~isempty(nlines)
+    rawXML = cell(nlines, 1);
+else
+    rawXML = {};
+end
+
+% Read XML file line-by-line into a cell array to make later export simpler
+fID = fopen(xmlfile, 'r');
+ii = 1;
+while ~feof(fID)
+    rawXML{ii} = fgetl(fID);
+    ii = ii + 1;
+end
+fclose(fID);
+end
+
+
+function [mymcode] = stripXML(rawXML)
+% Strip out XML header & footer
+% Limit search to first & last lines of file, currently all that is
+% modified by MATLAB to wrap the class definition in XML
+mymcode = rawXML;
+mymcode([1,end]) = regexprep(mymcode([1,end]), '(^.*)\[(?=classdef)|(?<=end)(\].*$)', '');
+end
+
+
+function writemfile(mymcode, pathname, appname)
+% Write a cell array of strings to a *.m file.
+% Assumes each cell is a separate line.
+fID = fopen(fullfile(pathname, sprintf('%s.m', appname)), 'w');
+for ii = 1:length(mymcode)
+    fprintf(fID, '%s\n', mymcode{ii});
+end
+fclose(fID);
+end
+
+
 function nlines = countlines(filepath)
 % Count the number of lines present in the specified file.
 % filepath should be an absolute path