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predelete_trigger_delete_action_pre_processing_.htm
Navigation:  ABC Library Reference > FileManager > FileManager Methods >====== PreDelete(trigger delete action pre-processing) ====== Previous pageReturn to chapter overviewNext page

PreDelete( ErrCode, ErrMsg ), returncode

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PreDelete Returns confirmation that valid dictionary trigger activity has occurred before a delete action is executed, and optionally sets an error code and message to be processed.
ErrCode A string constant, variable, EQUATE, or expression that represents an error code.
ErrMsg A string constant, variable, EQUATE, or expression that represents an error message.
returncode Indicates if an error occurs.

The PreDelete method is a virtual method that returns a TRUE value by default if pre-delete trigger activity was processed normally. The developer must set the return level to FALSE if any problems occurred in the pre-delete trigger activity code. When PreDelete returns FALSE, an ERRORCODE 100 (trigger error) is posted. If ErrCode is set, then FILEERRORCODE will be set to the contents of ErrCode when the error is processed by the ErrorClass object for the associated file (table). Similarly, FILEERROR will be set to ErrMsg.

The PreDelete method is accessible from a table's trigger properties located in the Dictionary Editor, or, in the Global Embeds of a target application

Implementation:

PreDelete is implemented using the file driver callback mechanism, therefore, this method will have access to all variables that the File Manager has access to. These variables and the ones added in the Data section of the method will allow the developer to insert code that will be executed after a CHANGE action for a file.

Return Data Type:     BYTE

Example:

 CODE

!Push any pending errors on stack, to allow trigger error detection

 PUSHERRORS()

 ReturnValue = PARENT.PreDelete(ErrCode,ErrMsg) !returns TRUE by default

 !trigger processing here ' optionally set ErrCode, ErrMsg and ReturnValue

 POPERRORS()

!restore errors saved on the stack

 RETURN ReturnValue

See Also:     PostDelete , PreInsert , PreUpdate

predelete_trigger_delete_action_pre_processing_.htm.txt · Last modified: 2021/04/15 15:57 by 127.0.0.1