Oracle Workflow Guide
Release 2.6.2

Part Number A95265-03
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Events

A business event is an occurrence in an internet or intranet application or program that might be significant to other objects in a system or to external agents. For instance, the creation of a purchase order is an example of a business event in a purchasing application. You can define your significant events in the Event Manager.

Oracle Workflow provides several predefined events for significant occurrences within the Business Event System. See: Predefined Workflow Events

When an event occurs in an application on your local system, an event key must be assigned to uniquely identify that particular instance of the event. Then the event must be raised to the Event Manager.

You can raise an event by any of the following methods:

Additionally, the Event Manager can receive events sent from the local system or remote systems.

When you define an event in the Event Manager, you must assign it a unique internal name, which is case-sensitive. The suggested format for these internal names is a compound structure of identifiers separated by periods (.) as follows:

<company>.<family>.<product>.<component>.<object>.<event>

This format allows you to organize the events you define into a classification hierarchy.

You can also define event groups that let you associate any events you want with each other and reference them as a group in event subscriptions. An event group is a type of event composed of a set of individual member events. The internal names of event groups should follow the same format as the names of individual events. Once you have defined an event group, you can register a subscription on the group rather than having to create separate subscriptions for each individual event within it. The subscription will be executed whenever any one of the group's member events occurs.

Note: Event groups cannot be used to raise events. You must raise each event individually.

Any detail information needed to describe what occurred in an event, in addition to the event name and event key, is called the event data. For example, the event data for a purchase order event includes the item numbers, descriptions, and cost. The event data can be structured as an XML document.

The application where the event occurs can include the event data when raising the event to the Event Manager. If the application will not provide the event data, you should specify a Generate function for the event that can produce the complete event data from the event name, event key, and an optional parameter list. The Generate function must follow a standard API. See: Raise and Standard API for an Event Data Generate Function.

The Event Manager checks each subscription before executing it to determine whether the subscription requires the event data. If the event data is required but is not already provided, the Event Manager calls the Generate function for the event to produce the event data. If the event data is required but no Generate function is defined for the event, Oracle Workflow creates a default set of event data using the event name and event key.

Note: If the Generate function is costly, and you want to return control to the calling application more quickly after raising the event, you can defer all the subscriptions that require the complete event data. Then the Event Manager will not run the Generate function until those subscriptions are executed at a later time. See: Deferred Subscription Processing.

If you use a program to create event definitions automatically, the program can set its own name and brief identifier as the owner name and owner tag for the events. The program can then use this identifying information to locate the events that it owns. You can use the Edit Event and Edit Group pages to update the owner name and owner tag manually if necessary.

See Also

To Define an Event

To Define an Event Group

To Find Events

To Update or Delete an Event

 
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