DODEFAULT( ) Function

Executes the parent class event or method of the same name from within a subclass.

For example, if you place DODEFAULT( ) in the Click event of a subclass, Visual FoxPro executes the Click event of the parent class. The scope resolution operator (::), unlike DODEFAULT( ), executes a parent class event or method of a different name.

Note   You can place DODEFAULT( ) only within an event or method.

DODEFAULT( [ eParameter1 [, eParameter2] ...] )

Parameters

• eParameter1 [, eParameter2] ...
  Specifies parameters that are passed to the parent class event or method.

Return Values

Character, Numeric, Currency, Date, DateTime, Logical, or Memo

Remarks

The value that DODEFAULT( ) returns is determined by the return value of the event or method.

In versions prior to Visual FoxPro 8.0, you could not call DODEFAULT( ) in a method that did not exist in the parent class without Visual FoxPro generating an error, "Property name is not found (Error 1734)", returning True (.T.), and disregarding DODEFAULT( ) and any passed parameters. However, Visual FoxPro now disregards this and does not generate an error, but the following results still occur:

• Visual FoxPro disregards any parameters that are passed because no code is executed.
• Visual FoxPro always returns True (.T.), which is the default behavior for any procedure without an explicit RETURN statement.

This behavior affects the following scenarios:

• Custom methods that are defined in a class. For example, the line, x.Test(), generated an error prior to Visual FoxPro 8.0 but no longer does:

  CLEAR
  x=CREATEOBJECT("s1")
  x.ReadMethod("Init")      
  x.Test()                  
  
  DEFINE CLASS s1 AS Session
     PROCEDURE Test
        DODEFAULT()
     ENDPROC
     PROCEDURE ReadMethod(cMethod)
        DODEFAULT(cMethod)
     ENDPROC
     PROCEDURE Error(nError, cMethod, nLine)
        ? "Error:", nError, cMethod, nLine
     ENDPROC
  ENDDEFINE
  

• Native methods that are marked with the HIDDEN key word in the parent class. For example:

  CLEAR
  x=CREATEOBJECT("s2")
  x.Test()
  
  DEFINE CLASS s2 AS s1
     PROCEDURE Test
        THIS.ReadMethod("Init")
     ENDPROC
     PROCEDURE ReadMethod(cMethod)
        DODEFAULT(cMethod)
     ENDPROC
  ENDDEFINE
  
  DEFINE CLASS s1 AS Session
     HIDDEN PROCEDURE ReadMethod(cMethod)
        DODEFAULT(cMethod)
     ENDPROC
     PROCEDURE Error(nError, cMethod, nLine)
        ? "Error:", nError, cMethod, nLine
     ENDPROC
  ENDDEFINE
  

Starting in Visual FoxPro 7.0, calling a native method in a base class that contains DODEFAULT( ) does not cause an error. For example:

CLEAR
x=CREATEOBJECT("s1")
x.ReadMethod("Init")

DEFINE CLASS s1 AS Session
   PROCEDURE ReadMethod(cMethod)
      DODEFAULT(cMethod)
   ENDPROC
   PROCEDURE Error(nError, cMethod, nLine)
      ? "Error:", nError, cMethod, nLine
   ENDPROC
ENDDEFINE

See Also

:: Scope Resolution Operator | ParentClass Property