This section provides step-by-step instructions for creating, modifying, and deleting triggers. Triggers affect all processes updating a database unlike, for example, environment variables such as $gtmroutines which work on a per process basis. Therefore, FIS recommends that you should always have carefully planned procedures for changing triggers in your production environment.
To create a new trigger for global node ^Acct("ID"):
Using your editor, create a trigger definition file called triggers.trg with the following entry:
+^Acct("ID") -name=ValidateAccount -commands=S -xecute="Write ""Hello Earth!"""Execute a command like the following:
$ mupip trigger -triggerfile=triggers.trg
This command adds a trigger for ^Acct("ID"). On successful trigger load, this command displays an output like the following:
File triggers.trg, Line 1: ^Acct trigger added with index 1 ========================================= 1 triggers added 0 triggers deleted 0 trigger file entries not changed 0 triggers modified =========================================
Now, every S[et] operation on the global node ^Acct("ID") executes the trigger.
Execute a command like the following:
$ mupip trigger -select="^Acct*"
This command displays the triggers. A sample output looks like the following:
;trigger name: ValidateAccount# cycle: 1
+^Acct("ID") -name=ValidateAccount -commands=S -xecute="Write ""Hello Earth!""" To modify an existing trigger for global node ^Acct("ID"):
You cannot directly replace an existing trigger definition with a new one. With the exception of -NAME and -OPTIONS, to change an existing trigger, you have to delete the existing trigger definition and then add the modified trigger definition as a new trigger. Note that GT.M performs two different trigger comparisons to match trigger definitions depending on whether or not S[ET] is the trigger invocation command. If there is a S[ET], then the comparison is based on the global name and subscripts, PIECES, [Z]DELIM, and XECUTE. If there is no SET, GT.M compares only the global node with subscripts and the -XECUTE code value.
Begin by executing the following command:
$ mupip trigger -select="^Acct*" Output file:
Specify trigger_mod.trg as the output file. This file contains entries like the following:
;trigger name: ValidateAccount# cycle: 1
+^Acct("ID") -name=ValidateAccount -commands=S -xecute="Write ""Hello Earth!"""Using your editor, open trigger_mod.trg and change + (plus) to - (minus) for the trigger definition entry for ValidateAccount and add a new trigger definition for ^Acct("ID"). To avoid inconsistent application behavior, it is important to replace an old trigger with a new one in the same transaction (Atomic). The trigger_mod.trg file should have entries like:
;trigger name: ValidateAccount# cycle: 1-^Acct("ID") -name=ValidateAccount -commands=Set -xecute="Write ""Hello Earth!"""
;trigger name: ValidateAccount#+^Acct("ID") -name=ValidateAccount -commands=Set -xecute="Write ""Hello Mars!""" Execute a command like the following:
$ mupip trigger -triggerfile=trigger_mod.trg
This command displays an output like the following:
File trigger_mod.trg, Line 1: ^Acct trigger deleted File trigger_mod.trg, Line 3: ^Acct trigger added with index 1 ========================================= 1 triggers added 1 triggers deleted 0 trigger file entries not changed 0 triggers modified =========================================
Congratulations! You have successfully modified the xecute string of ValidateAccount with the new one.
To delete an existing trigger for global node ^Acct("ID"):
Begin by executing the following command:
$ mupip trigger -select="^Acct*" Output file:
Specify trigger_delete.trg as the output file. This file contains entries like the following:
;trigger name: ValidateAccount# cycle: 3
+^Acct("ID") -name=ValidateAccount -commands=S -xecute="Write ""Hello Mars!"""Using your editor, change + (plus) to - (minus) for the trigger definition entry for ValidateAccount. Alternatively, you can create a file with an entry like -ValidateAccount.
Now, execute a command like the following:
$ mupip trigger -triggerfile=trigger_delete.trg
This command displays an output like the following:
File trigger_delete.trg, Line 2: ^Acct trigger deleted ========================================= 0 triggers added 1 triggers deleted 0 trigger file entries not changed 0 triggers modified =========================================
You have successfully deleted trigger "ValidateAccount".
To change a trigger name for global node ^Acct("ID"):
Using your editor, create a new file called trigger_rename.trg and add a trigger definition entry for ValidateAcct with the same trigger signature as ValidateAccount. Your trigger definition would look something like:
+^Acct("ID") -name=ValidateAcct -commands=S -xecute="Write ""Hello Mars!"""Verify that the ValidateAccount trigger exists by executing the following command:
$ mupip trigger -select="^Acct*" Output file:
Respond with an empty string (Press Enter). Confirm that the trigger summary report contains an entry like the following:
;trigger name: ValidateAccount# cycle: 3
+^Acct("ID") -name=ValidateAccount -commands=S -xecute="Write ""Hello Mars!"""Now, execute a command like the following:
$ mupip trigger -triggerfile=trigger_rename.trg
This command displays an output like the following:
========================================= 0 triggers added 0 triggers deleted 0 trigger file entries not changed 1 triggers modified =========================================
You have successfully changed the trigger name ValidateAccount to ValidateAcct.