Ho to copy an object (deep copy) which has inside another object

Hi,

I have an object (obj1) with the following properties:

        PipeName
        PipeVault
        UnLock
        Units

However the PipeVault is also an object (obj2) with the properties:

Name;
Value;

When I make a copy (deep copy) of the object (obj1) I get: obj1Copy and if I change one property like (obj1.PipeName) this change only affect the obj1.PipeName but not the obj1Copy.PipeName which is fine and is what I need. However if I change the property (obj1.PipeVault. Name) the obj1Copy.PipeVault. Name also change. Both classes (of obj1 and obj2) employ the matlab.mixin.Copyable. Therefore I expected the same behavior as for the obj1.PipeName. How can I make a deep copy of obj1 and I get a totally independent object obj2 ( that is if I change obj1.PipeVault. Name this would not change obj2.PipeVault. Name)

Kind regards,

Armindo

Answer 1

[Guillaume]

As per its documentation matlab.mixin.Copyable does not make a deep copy of the object properties even if they themselves derived from copyable: "In making a shallow copy, MATLAB® does not call copy recursively on any handles contained in property values." You actually have to override the copyElement to make the copy yourself:

classdef Pipe < matlab.mixin.Copyable
   properties
      PipeName;
      PipeVault;
      UnLock;
      Units;
   end
   methods (Access = protected)
      function thiscopy = copyElement(this)
         thiscopy = [e-mail](this); %shallow copy of all elements
         thiscopy.PipeVault = copy(this.PipeVault); %Deep copy of pipevault
      end
   end
end

[Alek Xu]

This seems to limit copy behavior for all other classes.