com.goldencode.p2j.persist.trigger

Class TriggerManagerHandle

java.lang.Object

com.goldencode.p2j.persist.trigger.TriggerManagerHandle

public class TriggerManagerHandle
extends java.lang.Object

A handle for avoiding accessing the TriggerManager directly via its public API. Objects of this class can be used for setting up generic triggers in a similar manner how session triggers are registered from converted code.

The generic triggers are Java callback methods which are invoked BEFORE the session database triggers, but they are configured for all tables (we may add a mask/regex pattern to filter only specific tables) of a database. The implementer is responsible to write the code for handling the event at a lower level, including table filtering (for the moment) but must take care of full 4GL state: transactions, locking, buffers, undo ability.

Field Summary

Fields

Modifier and Type	Field and Description
private DatabaseTriggerManager	manager The manager instance.

Constructor Summary

Constructors

Constructor and Description
TriggerManagerHandle() Default c'tor does nothing

Method Summary

Modifier and Type	Method and Description
java.lang.String	deregisterGenericTrigger(java.lang.String eventName, java.lang.String database) Unregister a previously set generic trigger given the event type and database/.
java.lang.String	deregisterGenericTrigger(java.lang.String eventName, java.lang.String database, java.lang.String property) Unregister a session database trigger for the given event type and buffer class.
private DatabaseTriggerManager	getManager() Obtain and caches the manager instance locally.
java.lang.String	registerGenericTrigger(java.lang.String eventName, java.lang.String database, java.lang.String triggerClassName) Register a generic trigger for a specific event.
java.lang.String	registerGenericTrigger(java.lang.String eventName, java.lang.String database, java.lang.String triggerClassName, java.lang.String property) Register a generic trigger for a ASSIGN event.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

manager

private DatabaseTriggerManager manager

The manager instance. Uses lazy instantiation.

Constructor Detail

TriggerManagerHandle

public TriggerManagerHandle()

Default c'tor does nothing

Method Detail

registerGenericTrigger

public java.lang.String registerGenericTrigger(java.lang.String eventName,
                                               java.lang.String database,
                                               java.lang.String triggerClassName)

Register a generic trigger for a specific event. When such trigger is registered, it will be fired for all events of that type, of all tables from specified database before any other configured session or schema trigger. The execution of the latter two is unaffected of the presence or execution of the generic trigger.

Parameters:

eventName - The event as case-insensitive string.

database - The database to apply to. (In future revisions, this parameter might be replaced by a table mask / pattern.)

triggerClassName - The trigger class which implements the method for handling the respective event in a generic manner.

Returns:

null if the operation is successful and a short description of the problem otherwise.

registerGenericTrigger

public java.lang.String registerGenericTrigger(java.lang.String eventName,
                                               java.lang.String database,
                                               java.lang.String triggerClassName,
                                               java.lang.String property)

Register a generic trigger for a ASSIGN event. When such trigger is registered, it will be fired for all ASSIGN events, of all tables from specified database BEFORE any other configured session or schema triggers. The execution of the latter two is unaffected of the presence or execution of the generic trigger.

Parameters:

eventName - The event as case-insensitive string.

database - The database to apply to. (In future revisions, this parameter might be replaced by a table mask / pattern.)

triggerClassName - The trigger class which implements the method for handling the respective event in a generic manner.

property - The property name of the affected field. (Also subject for replacing with a mask / pattern.)

Returns:

null if the operation is successful and a short description of the problem otherwise.

deregisterGenericTrigger

public java.lang.String deregisterGenericTrigger(java.lang.String eventName,
                                                 java.lang.String database)

Unregister a previously set generic trigger given the event type and database/. This is the equivalent of ON <event> OF <table> REVERT but for generic triggers.

Parameters:

eventName - The event as case-insensitive string.

database - The database to apply to. In future revisions, this parameter might be replaced by a table pattern.

Returns:

null if the operation is successful and a short description of the problem otherwise.

deregisterGenericTrigger

public java.lang.String deregisterGenericTrigger(java.lang.String eventName,
                                                 java.lang.String database,
                                                 java.lang.String property)

Unregister a session database trigger for the given event type and buffer class. This is the equivalent of ON Assign OF <table> REVERT but for generic triggers.

Parameters:

eventName - The event as case-insensitive string. Recommended ASSIGN but this variant of the method ignores the parameter.

database - The database to apply to. In future revisions, this parameter might be replaced by a table pattern.

property - The property that is deregistered from ASSIGN trigger.

Returns:

null if the operation is successful and a short description of the problem otherwise.

getManager

private DatabaseTriggerManager getManager()

Obtain and caches the manager instance locally.

Returns:

the manager instance.