Sending a Message to Yourself

Often, an object will send a message to itself. This means that the object that is sending the message is also the object receiving the message. When this occurs, the predefined keyword Self can be used to identify the object ID. In the following example, all messages within an object based on this class are sent to itself, so Self is used to identify the object ID of each message.

Class cMyButton is a Button
    Procedure Construct_Object
        Forward Send Construct_Object
        Property Integer piClickCount 0
    End_Procedure

    Procedure DoAction
        Integer iCount
        Get piClickCount of Self to iCount
        Move (iCount + 1) to iCount
        Set piClickCount of Self to iCount
    End_Procedure

    Procedure OnClick
        Send DoAction of Self
    End_Procedure
End_Class

Because this type of message sending occurs so often, the {of self} syntax may be omitted. When an object ID is not identified, the current object (self) is assumed. Therefore, the above example could be more easily written as:

Class cMyButton is a Button
    Procedure Construct_Object
        Forward Send Construct_Object
        Property Integer piClickCount 0
    End_Procedure

    Procedure DoAction
        Integer iCount
        Get piClickCount to iCount
        Move (iCount + 1) to iCount
        Set piClickCount to iCount
    End_Procedure

    Procedure OnClick
        Send DoAction
    End_Procedure
End_Class