Can I import classes in an interface class in matlab?

Hello everyone! Can I import other classes like BaseStation,Technology and Area in the interface class BsGridFactory which are in the datatypes package and the interface class is in another package? or I should import this classes in the implementation functions of subclasses of BsGridFactory?

createBaseStationGrid takes a users parameter which is an array of User objects, an area which is an Area object and a technology which is Technology object. Is the interface class written ok or should I remove the import statements? Thanks in advance!

Answer 1

[Guillaume]

I'm not sure what you mean by import.

All import does is to allow you to refer to functions and classes in packages without having to specify the name of the package. So if you have

import datatypes.BaseStation

that means you can then write

someresult = BaseStation.SomeFunction(somearguments);

instead of

someresult = datatypes.BaseStation.SomeFunction(somearguments);

That is all. So in a context of an interface that only has abstract methods the import are useless since you're not calling any function anyway.

[ana take]

In OOP languages like Java you have to import classes in the interface class(if you use an object of these classes as parameters of the method defined in the interface class), that's why I wanted to clarify my doubts.Thank you for your answer!

Answer 2

[Sean de Wolski]

You can import inside of the individual methods of a class but not globally for the whole class.

classdef x
  methods
    function foo(obj)
      import whatever.myclass
      myclass(3)
    end
  end
end

[ana take]

Thank you for your answer!

[Guillaume]

"You can import inside of the individual methods of a class but not globally for the whole class".

Oh yes, I'd forgotten about that. Major pain, that is!

My point still stand, within the context of an interface, where everything is abstract, there is no point in importing anything.

[Sean de Wolski]

One reason is to use short names. I do this quite frequently, especially for nested packages. Import a whole package:

import pack.subpack.*
p = subpackitem1;
p2 = subpackitem2;

I added my vote for the import long_name as short_name interface as well.

[Ashley Trowell]

Unfortunately, the import statement essentially obfuscates code, since it breaks the Ctrl + D functionality. The IDE doesn't seem to know where the code is defined. If you Ctrl + D on a imported function, you are told that it hasn't been defined, or are directed to a non package version, a version that won't actually be executed at runtime.

An import statement is critical for efficient development, but is a seriously broken feature in Matlab.

[Nikolaus Koopmann]

This! One of the most annoying aspects of writing OOP code in Matlab..