TIBCO BW Groups

TIBCO BW Groups:

Groups are used to specify related sets of activities. The main uses of groups are the following:

• To create a set of activities those have a common error transition. Basically, this is similar to a try...catch block in Java. This allows you to have a set of activities with only one error-handling transition, instead of trying to individually catch errors on each activity.

• To create sets of activities those are to be repeated. You can repeat the activities once for each item in a list, until a condition is true, or if an error occurs.

• To create sets of activities those participate in a transaction. Activities in the group that can take part in a transaction are processed together, or rolled back, depending upon whether the transaction commits or rolls back.

No Action Groups

You can group a set of related activities, with a common set of transitions into and out of the group. If you do not wish for the activities in the group to repeat, specify the group action to be none. No action groups are primarily useful for specifying a single error transition out of the group so that if an unhandled error occurs in the group, you only need one error transition instead of an error transition for each activity. This behavior is similar to a try...catch block in Java.

If Groups

You can use groups to conditionally execute business logic. The If group allows you to specify a set of conditions that are evaluated in order.

Critical Section Groups

Critical section groups are used to synchronize process instances so that only one process instance executes the grouped activities at any given time.

Any concurrently running process instances that contain a corresponding critical section group wait until the process instance that is currently executing the critical section group completes. Critical Section groups are particularly useful for controlling concurrent access to shared variables.

Overview of Loops

Loops allow you to execute a series of activities more than once. You can iterate based on the items in an array stored in the process data, you can iterate while or until a given condition is true, or you can iterate if an error is encountered while processing. The following are the types of loops that are available:

• Iterate Loop

• Repeat Until True Loop

• While True Loop

• Repeat On Error Until True Loop

Iterate Loop

An Iterate loop repeats the series of grouped activities once for every item in the list.

Repeat Until True Loop

The Repeat Until True loop repeats the series of grouped activities until the given condition evaluates to true. The activities are always executed once before checking if the condition is true. After executing the series of activities, the condition is checked, and the loop exits when the condition evaluates as true. Thefollowing is an example of a Repeat Until True loop.

While True Loop

The While True loop repeats the series of grouped activities as long as the given condition evaluates as true. The condition is evaluated when the group is entered. If the condition evaluates to false, the activities within the group are not executed.

Repeat On Error Until True Loop

The Repeat On Error Until True loop allows you to repeat a series of activities when an unhandled error occurs. The activities in the group are executed once. If there are no unhandled errors, the loop terminates. If an error occurs for which there is no error transition, the condition of the loop is evaluated — if the condition is true, the loop terminates, if the condition is false, the loop repeats until there is no error occurs or the condition is true.