Converting class properties to struct respecting visibility

Question

I'm working on a simulink model that is configured on different modes that change the model parameters based on the stuff like the chosen sample rate filter group delay, etc...

I though of setting all the parameters on a ParameterStruct, then load the proper parameter struct for each mode.

This sort of maps well to a class with Dependent properties because, there are a lot of model parameters that are generated from only a couple inputs.

But when I try to generate an struct from the a class visibility is not respected:

classdef SquareArea
   properties
      Width
      Height
   end
   properties (Access =private)
      Hidden
   end
   properties (Dependent)
      Area
   end
   methods
      function a = get.Area(obj)
         a = obj.Width * obj.Height;
      end
   end
end

>> x=SquareArea

x = 

  SquareArea with properties:

     Width: []
    Height: []
      Area: []

>> struct(x)
Warning: Calling STRUCT on an object prevents the object 
from hiding its implementation details and should thus
be avoided. Use DISP or DISPLAY to see the visible public
details of an object. See 'help struct' for more information.

ans = 

     Width: []
    Height: []
    Hidden: []
      Area: []

This is not acceptable, because I need to export the struct to C afterwards, to be able to set the mode dynamically from the generated code.

score 2 · Answer 1 · answered Feb 26 '18 at 22:18

Combining the answers from Amro & DVarga, a default struct function can be generalised:

     function s = struct(self)
        publicProperties = properties(self);
        s = struct();
        for fi = 1:numel(publicProperties)
            s.(publicProperties{fi}) = self.(publicProperties{fi}); 
        end                  
    end

score 1 · Answer 2 · answered Apr 09 '16 at 18:01

1

publicProperties = properties(x);
myStruct = struct();
for iField = 1:numel(publicProperties), myStruct.(publicProperties{iField}) = []; end

answered Apr 09 '16 at 18:01

DVarga

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score 1 · Accepted Answer · answered Apr 09 '16 at 18:04

You could override the default struct for your class:

classdef SquareArea
   properties
      Width = 0
      Height = 0
   end
   properties (Access=private)
      Hidden
   end
   properties (Dependent)
      Area
   end
   methods
      function a = get.Area(obj)
         a = obj.Width * obj.Height;
      end
      function s = struct(obj)
          s = struct('Width',obj.Width, 'Height',obj.Height, 'Area',obj.Area);
      end
   end
end

Now:

>> obj = SquareArea
obj = 
  SquareArea with properties:

     Width: 0
    Height: 0
      Area: 0
>> struct(obj)
ans = 
     Width: 0
    Height: 0
      Area: 0

Note that you can still get the original behavior by explicitly calling the builtin one:

>> builtin('struct', obj)
Warning: Calling STRUCT on an object prevents the object from hiding its implementation details and should
thus be avoided. Use DISP or DISPLAY to see the visible public details of an object. See 'help struct' for
more information. 
ans = 
     Width: 0
    Height: 0
    Hidden: []
      Area: 0

Converting class properties to struct respecting visibility

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