Business Events (What way they differ with triggers)

Question

Hello All,
I am quite confused about the concept of Business events.(I know we have subscription to events in the subscrition we can call workflow or call custom code.
For example when a user is created (event) we can perform some action(Subscription))
But in the above said exampel we can achieve the functionallity by using the concept of triggers.
Can any one explain where we use the business events concept.
Also when we define an event in a work flow we have options like SEND,RECEIVE,RAISE. Does they mean the follwoing
1)Receive: We Receive the event.i.e when event happens we come to know that event is raised and we need to take some action.
2)RAISE: With this option we are trying to raise the event in workflow.
3)SEND : we are sending the event to an exteranl system.
Kind Regards,
Kumar.
Edited by: user624202 on May 31, 2009 11:45 PM

Answer 1

Hi,
A trigger can only respond to something occurring in the database (e.g. logon, insert, update, delete). A business event can be raised by anything to indicate to the event manager that something significant has occurred - this might be from PL/SQL, from a form, from a trigger etc.
For example, if a user clicks a button in a form to cancel an action, there probably isn't going to be any database activity, so you couldn't use a trigger to perform some action. You could use a business event, though, since you can raise the event from PL/SQL easily.
I ALWAYS have a new process started by a business event, because it maximises the flexibility in the long term. If you want to change the processing, you can modify, add or remove subscriptions without the need to revisit any other code - if you disable the subscription(s), then the Event Manager just does nothing, so you can disable the functionality via a web-page rather than needing to modify any code to disable / enable the different processing.
Event activities in Workflow processes are (as you say) either receive, raise or send. Receive will respond to an event subscription when the event is raised to the Event Manager. Raise will raise a new business event to the Event Manager, which will then execute any subscriptions that exist for that event. Send will send the event to an agent - that may be within the same system or in a different one.
HTH,
Matt
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