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How to require a custom class type with addRequired?

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I have a custom class,
classdef foo
properties
%Property stuff
prop1;
end
methods
function obj = foo( )
%Constructor stuff.
obj.prop1 = 'test';
end
end
end
and I want the input of a function to require that the variable type is this custom class.
function out = fun( varargin )
p = inputParser;
addRequired( p, 'InputName', @(x) isa( x, 'foo' ) );
parse( p, varargin{:} );
% Function stuff
end
When I try doing this
% Script.
objInstance = foo();
out = fun( 'InputName', objInstance )
I get this error:
" The value of 'InputName' is invalid. It must satisfy the function: @(x)isa(x,'foo'). "

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Accepted Answer

Steven Lord
Steven Lord on 5 Dec 2019
You probably want to use addParameter instead of addRequired.
If you're using release R2019b or later, consider using function argument validation instead of inputParser.
But if this function requires an input of this class, should it be a separate function or should it be a method defined inside the class itself?
classdef foo
methods
function out = fun(x)
% x MUST be a foo (which could mean it's a subclass of foo)
end
end
end

  1 Comment

Dominik Mattioli
Dominik Mattioli on 5 Dec 2019
It took me a while but I finally understand why you suggested using addParameter instead. This is a great answer to a question that I now see is a little naive, thank you.

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More Answers (1)

Luna
Luna on 5 Dec 2019
Variable out is not defined in the function bar. Also bar is already a built-in function. Use another function name instead.

  1 Comment

Dominik Mattioli
Dominik Mattioli on 5 Dec 2019
I'll edit the question to have my original class and function names. I changed them to be easier to read for this question.

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