ENH - make some of the code more robust for string input

fileio/ft_filetype.m

@@ -162,6 +162,12 @@
   end
 end
 
+% some of the code does not work well on matlab strings, (i.e. "" vs ''),
+% specifically ["a" "b"] yields something different than ['a' 'b']. 
+if isstring(filename)
+  filename = char(filename);
+end
+
 % the parts of the filename are used further down
 if isfolder(filename)
   [p, f, x] = fileparts(filename);

fileio/ft_read_headshape.m

@@ -208,6 +208,12 @@
   return
 end % if iscell
 
+% some of the code does not work well on matlab strings, (i.e. "" vs ''),
+% specifically ["a" "b"] yields something different than ['a' 'b']. 
+if isstring(filename)
+  filename = char(filename);
+end
+
 % optionally get the data from the URL and make a temporary local copy
 filename = fetch_url(filename);
 

ft_defaults.m

@@ -14,6 +14,7 @@
 %   ft_default.checkconfig       = string, can be 'pedantic', 'loose', 'silent' (default = 'loose')
 %   ft_default.checkpath         = string, can be 'pedantic', 'once', 'no' (default = 'pedantic')
 %   ft_default.checksize         = number in bytes, can be inf (default = 1e5)
+%   ft_default.checkstring       = string, can be 'yes' or 'no' (default = 'yes'), convert "strings" in cfg to 'chars'
 %   ft_default.showlogo          = string, can be 'yes' or 'no' (default = 'yes')
 %   ft_default.showcallinfo      = string, can be 'yes' or 'no' (default = 'yes')
 %   ft_default.trackcallinfo     = string, can be 'yes' or 'no' (default = 'yes')
@@ -98,6 +99,7 @@
 if ~isfield(ft_default, 'checkconfig'),       ft_default.checkconfig    = 'loose';    end % pedantic, loose, silent
 if ~isfield(ft_default, 'checkpath'),         ft_default.checkpath      = 'pedantic'; end % pedantic, once, no
 if ~isfield(ft_default, 'checksize'),         ft_default.checksize      = 1e5;        end % number in bytes, can be inf
+if ~isfield(ft_default, 'checkstring'),       ft_default.checkstring    = 'yes';      end % yes or no
 if ~isfield(ft_default, 'showlogo'),          ft_default.showlogo       = 'yes';      end % yes or no, this is relevant for SPM and EEGLAB
 if ~isfield(ft_default, 'showcallinfo'),      ft_default.showcallinfo   = 'yes';      end % yes or no, this is used in ft_pre/postamble_provenance
 if ~isfield(ft_default, 'keepprevious'),      ft_default.keepprevious   = 'yes';      end % yes, no, this is used in ft_postamble_previous

test/test_issue2082.m

@@ -0,0 +1,46 @@
+function test_issue2082
+
+% MEM 1gb
+% WALLTIME 00:30:00
+% DEPENDENCY ft_checkconfig
+% DATA public
+
+global ft_default
+
+cfg = [];
+cfg.dataset = string(dccnpath('/home/common/matlab/fieldtrip/data/ftp/test/ctf/Subject01.ds'));
+cfg = ft_checkconfig(cfg, 'dataset2files', 'yes');
+
+filename = string(dccnpath('/home/common/matlab/fieldtrip/data/ftp/test/ctf/Subject01.shape'));
+hs = ft_read_headshape(filename);
+
+% create a dummy cfg
+cfg.a = 'a';
+cfg.b = "b";
+cfg.c = 1;
+cfg.d.e = "e";
+cfg.d.f = 1;
+cfg.d.g.h = 'h';
+cfg.d.g.i = "i";
+cfg.d.g.j = {"a" "b"};
+k.a = "a";
+k.b = 'b';
+cfg.d.g.k = {k 1}; % this for now does not work
+
+cfg.checkstring = 'no';
+cfgout1 = ft_checkconfig(cfg);
+c = struct2cell(cfgout1);
+s = fieldnames(cfg);
+t = cellfun(@class, c, 'UniformOutput', false);
+assert(any(strcmp(t, 'string')));
+
+cfg.checkstring = 'yes';
+cfgout2 = ft_checkconfig(cfg);
+
+c = struct2cell(cfgout2);
+t = cellfun(@class, c, 'UniformOutput', false);
+assert(~any(strcmp(t, 'string')));
+
+c = struct2cell(cfgout2.d);
+t = cellfun(@class, c, 'UniformOutput', false);
+assert(~any(strcmp(t, 'string')));

utilities/ft_checkconfig.m

@@ -92,6 +92,12 @@
   pedantic = false;
 end
 
+if isfield(cfg, 'checkstring')
+  checkstring = cfg.checkstring;
+else
+  checkstring = 'no';
+end
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % rename old to new options, give warning
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -607,6 +613,17 @@
   end
 end
 
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% checkstring, i.e. convertStringsToChar
+%
+% Converts "strings" to 'chars' if necessary.
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+if istrue(checkstring)
+  cfg = checkstringfun(cfg);
+end
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % checkinside, i.e. inside2logical
 %
@@ -750,6 +767,35 @@
   end % for numel(cfg)
 end % for each of the fieldsorig
 
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% SUBFUNCTION
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+function [cfg] = checkstringfun(cfg)
+
+c = struct2cell(cfg);
+s = fieldnames(cfg);
+t = cellfun(@class, c, 'UniformOutput', false);
+
+% convert
+[c{:}] = convertStringsToChars(c{:});
+cfg = cell2struct(c,s,1);
+
+% deal with cell-arrays
+if any(strcmp(t, 'cell'))
+  fn = s(strcmp(t, 'cell'));
+  for k = 1:numel(fn)
+    [cfg.(fn{k}){:}] = convertStringsToChars(cfg.(fn{k}){:});
+  end
+end
+
+% recurse
+if any(strcmp(t, 'struct'))
+  fn = s(strcmp(t,'struct'));
+  for k = 1:numel(fn)
+    cfg.(fn{k}) = checkstringfun(cfg.(fn{k}));
+  end
+end
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % SUBFUNCTION converts a cell-array of structure arrays into a structure array
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

utilities/private/dataset2files.m

@@ -38,6 +38,11 @@
   return
 end
 
+if isstring(filename)
+  % the below code does not deal well with matlab strings (i.e. "" vs. '')
+  filename = char(filename);
+end
+
 if isempty(format)
   format = ft_filetype(filename);
 end