MATLAB: Hide class property, but retain autocomplete

command windowhandle classhidden propertyMATLABoop

Hi all,

Following question:

I have a handle class, and I'd like to hide certain properties from being displayed in the command window when I type an object. To do this, I define the property as hidden:

classdef xy < handle
    properties (Hidden)
        abc
    end
end

Now if do so, I lose autocomplete capability in the command window:

my_obj = xy();
xy.[TAB]

(autocomplete only works if abc has no Hidden attribute).

So, my question is: How can I can hide a property from display, but keep it autocompleting in the command window?

Thank you very much!

Philip

Best Answer

Hidden means hidden, from display and autocompletion. There's no workaround.

However, what you could do is customise the display of your class, so that it only displays whatever you want even if the property is not hidden. For that you'd have to derive your class from matlab.mixin.CustomDisplay and override getPropertyGroups to omit the property you want to hide.

All in all, a lot of works for something that doesn't sound very logical.

Related Solutions

MATLAB: Is is possible to control the order of inherited class properties

Following the advice of William Warriner, here is what can be done. Change Example_Class_2 as follows:

classdef Example_Class_2 < Example_Class_1 & matlab.mixin.CustomDisplay
    properties
        Property3
    end
    methods (Hidden)
        function value = properties( obj )
            propList = sort( builtin("properties", obj) );
            if nargout == 0
                disp(propList);
            else
                value = propList;
            end
        end
        function value = fieldnames( obj )
            value = sort( builtin( "fieldnames", obj ) );
        end
    end
    methods (Access = protected)
        function group = getPropertyGroups( obj )
            props = properties( obj );
            group = matlab.mixin.util.PropertyGroup( props );
        end
    end
end

Now, properties are listed in alphabetical order, both when displayed on the command line, and when returned as a cell array (with e.g. propList = properties(Example_Class_2))

Of course, you don't have to use sort() to re-order the property list in the properties method. In my case, I needed a different ordering and just used

propList = builtin("properties", obj);
propList = propList([<my custom indices order>]);

MATLAB: How to hide away properties of an object

I don't think there's any way to hide private properties from struct.

The only workaround I could think of would be to store the private properties in another class (handle) and use a persistent containers.Map in a function to access that class. Would be a bit of a hassle, so you need to really want to hide these properties:

classdef ClassWithPropertiesToHide
   properties  (Access = public)   %properties that are public, hence don't need hiding
      something;
   end
   properties  (Access = private)
      objectID;    %will be visible through struct, but useless. Used as key in the container.Maps which unfortunately can't use a class as a key
   end
   methods (Access = public)
      function this = ClassWithPropertiesToHide()
         persistent idcount;  %unique id for each class instance to be used as key in the map
         if isempty(idcount)
            idcount = 0;
         else
            idcount = idcount + 1;
         end
         this.objectID = idcount;
         privateprops = GetPrivateProperties(this);   %privateprops is a handle class, so can be modified here
         privateprops.someprop = somevalue;
         privateprops.someotherprop = someothervalue;
      end
      function someotherfunction(this)
          privateprops = GetPrivateProperties(this);  %get private properties
          %do something
      end
   end
   methods (Access = private)
      function privateprops = GetPrivateProperties(this)
         persistent propcontainer;
         if isempty(propcontainer)
            propcontainer = containers.Map;
         end
         if ~isKey(propcontainer, this.objectID)
            propcontainer(this.objectID) = PrivatePropertiesClass  %PrivatePropertiesClass is the class to hold the private properties. Its properties have to be public
         end
         privateprops = propcontainer(this.objectID);
      end
   end
end

Edit: The main class probably needs a destructor and a slightly more sophisticated implementation of GetPrivateProperties so that when an instance of the main class is destroyed its private properties are also removed from the map. Otherwise, memory usage can only go up. Left as an exercice to the reader...

Best Answer

Related Solutions

MATLAB: Is is possible to control the order of inherited class properties

MATLAB: How to hide away properties of an object

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