4glWorks reference: Error Handlers

invalid_message

file ierrl.4gl
declaration
function invalid_message(m)
    define m	smallint
returns nothing
purpose Used from within viewers or scrollers to warn the user that an invalid message has been detected
example see afw_init
notes
  • Outputs additional diagnostic information on the application log, like user, and menu event chain
  • Prompts user for 2 possible action: continue and quit

invalid_viewer

file ierrl.4gl
declaration
function invalid_viewer(v)
    define v	smallint
returns nothing
purpose Used from within the main program to warn the user that an attempt was made to invoke an invalid viewer.
example none
notes see invalid_message

new_log

file ierrl.4gl
declaration
function new_log()
returns nothing
purpose Empties and enters a timestamp in the application error log
example none
notes none

trap_err

file ierrl.4gl, oerrl.4gl
declaration
function trap_err()
returns nothing
purpose A simple error trapper that outputs added diagnostic information to the error log (eg user, chain of menu entries that lead to the error). Depending on the type of application (command line or interactive), the action taken is to either to terminate the application, or to prompt the user.
example none
notes to be used within WHENEVER ERROR statements


Please address questions or comments to marco greco
(last updated Thu, 28 March 2002 16:09:54 GMT)