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How to implement a setter restriction?

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When making a user-defined class myClass that inherits from matlab.mixin.SetGet, how can I restrict the Set for a property prop1? Say that I want to allow only true/false sets for a property.
classdef myClass < handle & matlab.mixin.SetGet
properties (Access = public)
prop1
end
methods
%% Setter restrictions
% This is what I would do if it weren't a subclass of matlab.mixin.SetGet {
function set.prop1(self,value)
% Prevent non-boolean input value sets.
if value == true
self.prop1 = true;
else
self.prop1 = false;
end
end
%}
end
end
I like the syntax of matlab.mixin.SetGet so I'd prefer to not code it this way.

  5 Comments

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Walter Roberson
Walter Roberson on 31 Jan 2019
It would go right after
% Prevent non-boolean input value sets.
Are you hoping for a mechanism to add type restrictions on the calls themselves, such as (hypothetically) through the methods attributes list, so that MATLAB does the type filtering for you, without you having to put in a type check yourself ?
Dominik Mattioli
Dominik Mattioli on 31 Jan 2019
Ah I see.
I am not necessarily looking fo that extensive of a restriction. Ideally, your suggested code would be enough. Then a set method call would look like this (ignoring that I forgot to write a constructor in the original question):
mc = myClass();
mc.set('prop1',false) % or: mc.set('prop1',0);
%%% Error produced by:
propVal = 99
mc.set('prop1',propVal)
Walter Roberson
Walter Roberson on 31 Jan 2019
If you want to permit 0 and 1 as well as true and false, then I note that ismember() of 0 or 1 against true false works, and ismember() of true or false against 0 1 works, and that true == 1 and 0 == false work.

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Accepted Answer

Steven Lord
Steven Lord on 1 Feb 2019
If you just want to accept 0, 1, true, and false try using the mustBeNumericOrLogical property validation function. See the "Constrain Property to Numeric or Logical Values" example on that documentation page to see how to use it.

  2 Comments

Dominik Mattioli
Dominik Mattioli on 1 Feb 2019
Walter's comments were helpful but this is exactly what I'm looking for.
Steven Lord
Steven Lord on 1 Feb 2019
You may want to also include some of the other property validation functions to lock down not only the type of the property but also the value. mustBeGreaterThanOrEqual and mustBeLessThanOrEqual or mustBeMember are possibilities, or you could define your own validation function as described in the "Define Validation Functions" section on the page to which I linked in the first line of this comment.

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