How do I use the SUBSREF function to behave as the BUILTIN only for a subset of subscripted references in MATLAB 7.8(R2009a)?

I would like to create a SUBSREF function for my class. I am coding the SUBSREF method to behave like a custom SUBSREF for a subset of the subscription symbols and behave like the builtin SUBSREF for the rest. This presents a challenge, as the private and protected properties and methods are accessible inside the custom SUBSREF function. What steps can I take to make sure my private and protected properties and methods are not visible?

Reproduction Steps:

classdef testclass

      properties (Access = protected)

          prop1 = 1;

          prop2 = 2;

      end

      % constructor

      methods (Access = public)

          function TC = testclass()

          end

      end

      % Overloaded subsref

      methods

          function vals = subsref(TC,s)

              switch s(1).type

                  case '.'

                      vals = builtin('subsref',TC,s);

                  case '()'

              end

          end

      end

      methods (Access = protected)

          function showvals(TC)

              disp('prop1 =');

              disp(TC.prop1);

              disp('prop2 =');

              disp(TC.prop2);

          end

      end

end

t = testclass

t.prop1

Answer 1

[MathWorks Support Team]

This can be acheived by checking for the access information for the Properties and having an if - else statement so that SUBSREF behaves as intended.

An example of the check that you can perform is as follows:

if any(strcmp(s(1).subs,properties(TC))) || any(strcmp(s(1).subs,methods(TC)))

vals = builtin('subsref',TC,s);  

else

error(['''%s'' is not a public property or method of the ''testclass'' class.'],s(1).subs);

end

Another way to get information about the properties of the class is to use meta.class option.

mc = metaclass(TC);

p = [mc.Properties{:}];

   names = {p.Name};

p(strcmp('prop1, names)).GetAccess