Custom class properties and method attributes

Is there a way to add custom property or method attributes to handle classes? It is done by several classes or toolboxes, e.g. the unit testing framework allows to add tags to the methods: Tag Unit Tests - MATLAB & Simulink (mathworks.com)

classdef ExampleTagTest < matlab.unittest.TestCase
    methods (Test)
        function testA (testCase)
            % test code
        end
    end
    methods (Test, TestTags = {'Unit'})
        function testB (testCase)
            % test code
        end
        function testC (testCase)
            % test code
        end
    end 

I'm talking about the attributes "Test" and "TestTags".

My application would greatly benetfit from a finer granular control of properties for a DTO (data transfer object) class. I want to use argument validation but add additional options like overridable properties and don't want to use inputParser anymore :)

Thanks!

[Matt J]

and don't want to use inputParser anymore

Why not? It's more flexible than argument validation.

[Jan Kappen]

Slower, bulkier, no auto completion, older... The new argument validations are awesome.

[Matt J]

They're convenient when all the validation can be done inline, but for what you describe, it sounds like you're going to have to write your own custom validation function anyway.

[Jan Kappen]

You're right - a custom validation function will be used. But I'd nevertheless like to use the property validation combined with a separate validation function.

Reasons are simple, arguments get casted to expected data types and early errors are thrown when mandatory (non-default) properties are missing (to be set by the constructor). I can see, what properties (a.k.a input parameters) are available and I can use meta class/property data to iterate through all of them etc.

Plus, I have awesome auto completion proposals, via

function obj = SensorYieldAnalysisHelper(PropertyArgs)
%SensorYieldAnalysisHelper Construct an instance of this class
%   Detailed explanation goes here
    arguments
        PropertyArgs.?SensorYieldAnalysisHelper % support all public properties AND automatic parameter completion!
    end
end

I mean, how cool is that?

Does anything above work with inputParser (honest question!)?

[Jim Svensson]

As far as I know Matlab does not (version<=R2023) support custom property attributes. But if you are not using some of the existing ones for anything you might use them. For example SetObservable or GetObservable can be used to mean something else if you are not using listeners.

[Jan Kappen]

Thanks for that recommendation but I'm quite reluctant to abuse existing attributes that have a pretty clear meaning :)

Answer 1

[Matt J]

I don't know why it's not documented, but apparently there is a Description attribute that can be added, e.g.,

classdef myclass  
    
    properties (Description='propTag')
       prop 
    end

    methods (Description='methTag')
        function meth1

        end        
    end
    
    methods
        function meth2
            
        end
        
    end
    
end

[Jan Kappen]

Wow!

This is awesome, how do you know that?

Would you expect that Description field to be existent in the next releases?

mm = 

class with properties:

Name: 'myclass'
Description: ''
DetailedDescription: ''
Hidden: 0
Sealed: 0
Abstract: 0
Enumeration: 0
ConstructOnLoad: 0
HandleCompatible: 1
InferiorClasses: {0×1 cell}
ContainingPackage: [0×0 meta.package]
RestrictsSubclassing: 0
PropertyList: [1×1 meta.property]
MethodList: [26×1 meta.method]
EventList: [1×1 meta.event]
EnumerationMemberList: [0×1 meta.EnumeratedValue]
SuperclassList: [1×1 meta.class]

>> mm.PropertyList

ans = 

property with properties:

Name: 'prop'
Description: 'propTag'
DetailedDescription: ''
GetAccess: 'public'
SetAccess: 'public'
Dependent: 0
Constant: 0
Abstract: 0
Transient: 0
Hidden: 0
GetObservable: 0
SetObservable: 0
AbortSet: 0
NonCopyable: 0
PartialMatchPriority: 1
GetMethod: []
SetMethod: []
HasDefault: 0
Validation: [0×0 meta.Validation]
DefiningClass: [1×1 meta.class]

edit: okay found the threads: oop - Description and DetailedDescription attributes of MATLAB classes - Stack Overflow and https://undocumentedmatlab.com/articles/undocumented-classdef-attributes. Very interesting.

[Matt J]

Would you expect that Description field to be existent in the next releases?

Since it's not documented, it's hard to know for certain. Hopefully, someone from the MathWorks will weigh in.

Does this address your question, though? If so, I'd be much obliged if you would Accept-click the answer.

[Ill-Conditioned Matrix]

The problem is that Description and DetailedDescription come from the comment block before the property declaration. If you set Description from the property declaration, it will override the comments, but I'm not sure whether we can rely on that behavior.