Declaration Is Hidden (DIH)

Description:

DIH detects declarations that hide other visible declarations. These are:

• Local variables or method parameters that shadow fields of the containing class. As far as it is common practice in constructors to use formal parameters with the same name as class components, DIH detects situations where a class field is explicitly accessed by using self reference and does not produce a warning message in this case.

  When the option Include inherited fields is set in the audit properties, DIH considers not only fields declared by a class, but also all of the inherited ones.

• Methods that hide class methods declared in superclasses.
• Fields that hide fields declared in superclasses.

Incorrect:

Container = class

    private
    size:integer;
    
    public
    procedure copyFrom(c:Container);
end;
...
    procedure Container.copyFrom(c:Container);
    var size:integer;
    begin
        size := c.size;
        ...
    end;

Correct:

Container = class

    private
    size:integer;
    
    public
    procedure copyFrom(c:Container);
end;
...
    procedure Container.copyFrom(c:Container);
    var newSize:integer;
    begin
        newSize := c.size;
        ...
    end;

Incorrect:

Window = class

    protected
      style:integer;

    public
    class function Create(...):Window;
end;

Button = class(Window)

    protected
    style:integer;

    public
    class function Create(...):Button;
end;

Correct:

Window = class

    protected
      style:integer;

    public
    class function Create(...):Window;
end;

Button = class(Window)

    protected
    extendedStyle:integer;

    public
    class function CreateButton(...):Button;
end;

Refactoring:

• Rename Method