Class: ProceedingNotification

• Inheritance
• Description
• Instance protocol
  • default actions
• Examples

Inheritance:

   Object
   |
   +--GenericException
      |
      +--Notification
         |
         +--ProceedingNotification
            |
            +--SimpleView::AboutToOpenBoxNotificationSignal
            |
            +--SimpleView::BoxClosedNotificationSignal
            |
            +--SimpleView::CloseBoxRequestSignal

Package:

stx:libbasic

Category:

Kernel-Exceptions

Version:

rev: 1.5 date: 2021/11/21 10:09:02

user: cg

file: ProceedingNotification.st directory: libbasic

module: stx stc-classLibrary: libbasic

Description:

A ProceedingNotification behaves much like a regular notification,
in that if no handler is present, execution proceeds after the raise.
However, iff a handler simply falls through, the exception is proceeded.
The handler is still free to choose for an explicit action (return/reject).

copyright
COPYRIGHT (c) 2013 by eXept Software AG
             All Rights Reserved

This software is furnished under a license and may be used
only in accordance with the terms of that license and with the
inclusion of the above copyright notice.   This software may not
be provided or otherwise made available to, or used by, any
other person.  No title to or ownership of the software is
hereby transferred.

Instance protocol:

 doCallHandler: aHandlerBlock

call the handler proper - if the handler falls through, proceed with the handler's value.
- an extra method is needed to have a raise-marked context around.
(see implementation of #reject and #proceed).

Examples:

  |zero|

  zero := 0.
  ProceedingNotification handle:[:n |
      Transcript showCR:'h: ' , n description.
  ] do:[
      Error handle:[:ex |
          Transcript showCR:'some error: ' , ex errorString.
          ex proceed
      ] do:[
          [
              |answer|

              1 // zero.  'an error which is caught in the handler'.
              answer := ProceedingNotification notify:'hello world'.
              Transcript show:'after notification: '; showCR:answer.
          ] value
      ]
  ].

  |zero|

  zero := 0.
  ProceedingNotification handle:[:n |
      Transcript showCR:'h: ' , n description.
      n return.
  ] do:[
      Error handle:[:ex |
          Transcript showCR:'some error: ' , ex errorString.
          ex proceed
      ] do:[
          [
              |answer|

              1 // zero.  'an error which is caught in the handler'.
              answer := ProceedingNotification notify:'hello world'.
              Transcript show:'after notification 1: '; showCR:answer.
          ] value
      ]
  ].