topic Re: Singleton Class in Application Development and Automation Discussions

Singleton Class

Former Member — Thu, 10 Mar 2005 10:46:49 GMT

HI,

Can any one give me code of singleton class.

Regards

Vinay

Re: Singleton Class

Former Member — Thu, 10 Mar 2005 11:33:25 GMT

Hello Vinay,

Could you specify what the context is ? A singleton class, as I understand, is the one which has only one instance per session.

Now, do you want to create one class? For what purpose?

Regards,

Anand Mandalika.

Re: Singleton Class

ChristianFi — Thu, 10 Mar 2005 11:41:59 GMT

create a class with definition create private to make sure that no instance can be created from outside of the class.

define a static attribute wich holds the instance.

create the instance in a class method or in the class constructor and only if the static attribute is initial.

Christian

Re: Singleton Class

former_member183804 — Sun, 13 Mar 2005 09:08:18 GMT


program pattern_singleton.


***********************************************************************
* Singleton
* =========
*   Intent
*   ------
*   Ensure a class has only one instance, and provide a global point
*   of access to it.
***********************************************************************

class lcl_Singleton definition create private.

  public section.

    class-methods:
      get_Instance returning value(Result) type ref to lcl_Singleton.

  private section.
    class-data:
      fg_Singleton type ref to lcl_Singleton.

endclass.



class lcl_Singleton implementation.

method get_Instance.
  if ( fg_Singleton is initial ).
    create object fg_Singleton.
  endif.
  Result = fg_Singleton.
endmethod.

endclass.

Re: Singleton Class

Former Member — Mon, 14 Mar 2005 03:58:14 GMT

Thanks for the code, Klaus.

Regards,

Subramanian V.