EM: File System > Triggers

Description

Triggers are a powerful feature of the BBj file system and database that allow developers to execute BBj code whenever specific operations occur on a file. They can be used to validate data before writing it, verify permissions before allowing a user to read or write, perform data manipulation prior to saving information to a file or database table, and support many additional use cases. Developers can manage triggers through the graphical interface in the Enterprise Manager or programmatically by using the CREATE TRIGGER statement to control file triggers via SQL.

Location

EM Navigator → File System → Triggers

Toolbar

Button	Function
	Opens folder browser to add a new mounted directory.
	Opens a confirmation dialog to unmount and remove the selected directory.
	Creates a new folder within currently displayed directory.

Configuring and Managing Triggers

Triggers in BBj operate at the file level, meaning they fire regardless of whether the file operation is a READ RECORD issued by a BBj program or an SQL operation executed through a third party ODBC/JDBC application.

The top section of the panel displays the configured databases along with any mounted directories. Mounted Directories represent the filesystem locations that the administrator has explicitly selected for trigger visibility. To be able to access triggers on files in a particular directory (if they are not part of a configured BBj database), BBj needs to know that it should look in required directories for files with triggers.

Adding a Trigger to a Database Table

Select the database from the list of databases under the Databases item. Then double click the table to add a trigger or add triggers to multiple tables by selecting the desired tables and click the or buttons.

Mounting a Trigger Directory

This is only necessary when an administrator needs to manage triggers on files that are not part of a configured BBj database.

Select the Mounted Directories item.
Click the button in the toolbar.
Choose the directory from your local system to add, or click button to create a new folder.

After mounting the appropriate directory, add a trigger as follows:

Locate the file in the list of Files Without Triggers.
Double click the file to add a trigger or add triggers to multiple files by selecting the desired files and click the button.

Configuring a Trigger

To configure a trigger, double-click the trigger from the list which opens the Trigger Editor.

File Triggers

The File Triggers panel displays all trigger categories and configuration options for the selected data file, allowing administrators to manage trigger settings and review associated operational behaviors.

Data File: Displays the full path of the selected data file for viewing and configuring its associated triggers.

File Triggers Settings List

Value	Description
Property	The trigger categories and configuration options for the selected data file, enabling management of all supported trigger operations.
Value	Enable users to modify trigger properties by selecting boolean options such as true or false, choosing from predefined classpath entries, or specifying a program file. Depending on the property type, clicking the field opens either a dropdown list of available values or a file-browser dialog where users may navigate folders, create new directories, enter a file name, and select a program file to assign.
Description	The explanatory text for each trigger property, detailing its purpose and how the setting affects trigger behavior.

General Trigger Settings

General Trigger Settings provide options to enable triggers, define execution paths, specify user credentials, and configure classpath or session-specific settings for trigger processing.

General Trigger Settings List

Value	Description
Enabled	Enable or disable the use of triggers on the file. This must be enabled for any triggers on the file to be available. Note: When triggers are enabled on a file, if there is any kind of problem with the configuration or if the trigger code does not operate properly, the file may not be accessible until the problem is resolved or triggers are disabled.
Working Directory	Working directory for the running interpreter used by the trigger to execute the trigger code.
Config File	Location of a specific config.bbx file to use for this particular set of triggers. Leave blank to use the default config.bbx.
Run As User	User account to use for running the interpreter used for executing the trigger code. Leave blank to use the default user.
Run As Password	Password for the "run as user".
Classpath	An optional BBj Session Specific Classpath to use for the triggers.

Configuring Each Type of Trigger

Configuring each trigger type allows enabling specific actions, assigning program files, and defining source code behavior for all read-related operations. Most operations possible on data files may also have triggers attached to them. The following list describes the different operations that can occur on a file and thus have triggers attached to them.

Types of Triggers List

Value	Description
Read Triggers	Read triggers occur when a read operation is performed on a file. This includes SQL fetch operations, BBj READ and READ RECORD calls, SELECT verb calls, and EXTRACT calls.
Write Triggers	Write triggers occur when a write operation of any kind occurs. This includes SQL UPDATE and INSERT operations, and BBj WRITE and WRITE RECORD calls.
Remove Triggers	Remove triggers occur when a record is removed from a file. These include SQL DELETE operations as well as BBj REMOVE calls.
Key Triggers	Key triggers occur when one of the BBj language functions KEY, KEYF, KEYL, KEYN, or KEYP are called.
Erase Triggers	Erase triggers occur when a file is erased. These include SQL DROP table operations and BBj ERASE calls.
Open Triggers	Open triggers occur when a file is opened. These occur any time the file is opened regardless of whether it was from an SQL statement or a BBj OPEN call.
Close Triggers	Close triggers occur when a file is closed. These will occur when SQL operations are finished with a file, and when the BBj CLOSE call is executed.

Trigger Operation Properties

Trigger Operation Properties let administrators enable specific trigger types, assign operation-specific program files, and view read-only source code for Before, After, and Instead Of operations in the updated interface.

Trigger Operation Properties List

Settings	Description
Enabled	Enable or disable the specific type of trigger for the file. If a specific type is enabled and misconfigured in some way, the file will not be accessible.
<Type>Program	The BBj code to execute when the trigger fires. For information on how to program triggers. See: Programming Triggers.
Click to View	Displays the current source code for the trigger operation located in the file specified in Program. NOTE: The source code viewer in the Enterprise Manager is read-only.
Read-Only Code	BASIS advises using the BASIS IDE to edit trigger source code files to gain the benefit of syntax highlighting and other IDE features.

Timing Types

Each trigger fires at a particular point in the process of performing a particular file operation. The following describes the three times a trigger may fire:

Types	Description
Before	A before trigger is executed BEFORE the actual file operation occurs. This is useful, for example, when the data needs to validated before allowing a write.
After	An after trigger is executed AFTER the actual file operation occurs. After triggers have access to the data that was accessed during the actual file operation and can manipulate this data before it is returned to the client. One useful example would be an after read trigger that will decrypt data stored in the table before returning the data.
Instead of	Instead of triggers execute INSTEAD OF the actual file operation. These are useful if operations on that file should perform another operation such as get the data from a third party DBMS.