Added function to turn MATLAB objects to JSON ones

Author: k1o0

cb-tools/obj2json.m

@@ -0,0 +1,84 @@
+function s = obj2json(rig)
+% OBJ2JSON Converts input into JSON
+s = obj2struct(rig);
+if verLessThan('matlab','9.1')
+  s = savejson('', s);
+elseif verLessThan('matlab','9.3')
+  s = jsonencode(s);
+else
+  s = jsonencode(s, 'ConvertInfAndNaN', true);
+end
+end
+
+function s = obj2struct(obj)
+% OBJ2STRUCT Converts input object into a struct
+%   Returns the input but with any non-fundamental object converted to a
+%   structure.  If the input does not contain an object, the resulting
+%   output will remain unchanged.  
+%
+%   NB: Does not convert National Instruments object or objects within
+%   non-scalar structures.  Cannot currently deal with Java, COM or certain
+%   graphics objects.  Function handles are converted to strings.
+%
+% 2018-05-03 MW created
+
+if isobject(obj)
+  if length(obj) > 1
+    % If dealing with heterogeneous array of objects, recurse through array
+    s = arrayfun(@obj2struct, obj, 'uni', 0);
+  elseif isa(obj, 'containers.Map')
+    % Convert to scalar struct
+    keySet = keys(obj);
+    valueSet = values(obj);
+    for j = 1:length(keySet)
+      m.(keySet{j}) = valueSet{j};
+    end
+    s = obj2struct(m);
+  else % Normal object
+    names = fieldnames(obj); % Get list of public properties
+    for i = 1:length(names)
+      if isobject(obj.(names{i})) % Property contains an object
+        if startsWith(class(obj.(names{i})),'daq.ni.')
+          % Do not attempt to save ni daq sessions of channels
+          s.(names{i}) = []; 
+        else % Recurse
+          s.(names{i}) = obj2struct(obj.(names{i}));
+        end
+      elseif iscell(obj.(names{i}))
+        % If property contains cell array, run through each element in case
+        % any contain an object
+        s.(names{i}) = cellfun(@obj2struct, obj.(names{i}), 'uni', 0);
+      elseif isstruct(obj.(names{i})) && isscalar(obj.(names{i}))
+        % If property contains struct, run through each field in case any
+        % contain an object
+        s.(names{i}) = structfun(@obj2struct, obj.(names{i}), 'uni', 0);
+      elseif isa(obj.(names{i}), 'function_handle')
+        % Convert function to string
+        s.(names{i}) = func2str(obj.(names{i}));
+      elseif isa(obj.(names{i}), 'containers.Map')
+        % Convert to scalar struct
+        keySet = keys(obj.(names{i}));
+        valueSet = values(obj.(names{i}));
+        for j = 1:length(keySet)
+          m.(keySet{j}) = valueSet{j};
+        end
+        s.(names{i}) = obj2struct(m);
+      else % Property is fundamental object
+        s.(names{i}) = obj.(names{i});
+      end
+    end
+    s.ClassContructor = class(obj); % Supply class name for loading object
+  end
+elseif iscell(obj)
+  % If dealing with cell array, recurse through elements
+  s = cellfun(@obj2struct, obj, 'uni', 0);
+elseif isstruct(obj) && isscalar(obj)
+  % If dealing with structure, recurse through fields
+  s = structfun(@obj2struct, obj, 'uni', 0);
+elseif isa(obj, 'function_handle')
+  % Convert function to string
+  s = func2str(obj);
+else % Fundamental object, return unchanged
+  s = obj;
+end
+end