Organization of Object Oriented Code

Appologies if this is already answered somwhere ...

I'm trying to create an organizational structure fo my object oriented code. I think the best way to do it is with a combination of packages and classes. Currently, I have a folder structure something like this :

+MyPackage

+Foo

@bar

Inside +Foo I have a class definition for Foo. My inention is for this to be an abstract class that currently has no properties and only a constructor methods

classdef(Abstract) foo
    %FOO Summary of this class goes here
    methods(Abstract)
        function obj = foo()
            obj = [];
        end
    end   
end

Inside @bar I have a class definition with a single property defined with a contructor method for bar. I would like to have other methods be .m files in the @bar folder

classdef bar < foo
    %BAR Summary of this class goes here
    properties
        data
    end
    methods
        function obj = bar(data)
            obj = data;
        end
    end
    
end

My hope is to create an instance of foo by doing something like

obj = MyPackage.foo.bar(data)

Then access the not-yet-written methods in the @bar folder using something like

obj.modify_bar()

Howver, currently when I try to create a instance of bar I get the following error :

Error using MyPackage.foo.bar

The specified superclass 'foo' contains a parse error, cannot be found on MATLAB's search path, or is shadowed by another file with the same name.

foo appears ot the be on the matlab path because it's a package folder.

Am I do something fundementally worng? Should I be structuing my code in a different fashion? Sorry I'm new of object oriented programming in matlab.

[Jeff Miller]

Don't you need this?

classdef(Abstract = true) foo  % adding "= true"

[Alex]

perhaps, but I stil get the same error with = true

Answer 1

[FannoFlow]

Here is how I would recommend you create the folder structure:

+Package/+Foo/@Foo/Foo.m

+Package/+Foo/@Bar/Bar.m

Foo.m:

classdef (Abstract=true) Foo 
end

Bar.m:

classdef Bar < Package.Foo.Foo
    %BAR Summary of this class goes here
    properties
        data
    end
    methods
        function obj = Bar(data)
            obj = data;
        end
    end
end

And finally:

myBar = Package.Foo.Bar(42);
myBar.data