Working with structured activities

Here is a list of the structured activities that are relevant to this topic:

Choice activity

This activity evaluates the conditions on two or more control paths and follows the appropriate one. It can contain case and otherwise elements.

• Case element
• Used within a choice activity, this element is used to create a control path and define the conditions that will cause this path to run. When run, the process will evaluate the conditions in each of the case elements, and follow the first one that evaluates to true.

• Otherwise element
• Use this element within a choice activity to create a control path that will run when none of the other cases evaluate to true. Use this element on only one of the paths within a choice activity. When run, the process will evaluate the conditions in each of the case elements, and should none of them evaluate to true, it will run the activities in this path.

Generalized flow activity

Use this activities to nest activities on individual, customized control paths. This activity is equivalent to the concept of split/merge: although there are multiple paths within the activity, only the path that evaluates to true will be followed, and the target activity will start the moment that path has completed.

• Link
• Use the link within a Generalized flow activity to connect nested activities and form individual control paths. The link is used to express a synchronization dependency. In other words, it runs under a constraint because the link creates a dependency of one activity and the variables it uses on another activity. You can specify a transition condition on the link in the properties area of the BPEL process editor.

For Each activity

The For Each activity repeatedly runs the activities that it contains either sequentially or in parallel for a specified number of iterations.

The related link For Each activity - a typical usage pattern provides excellent information on getting started with For Each activities.

For an example of how to use an assign activity to iterate an array in a For Each activity, see Using assign.

Parallel activity

Use this activity to nest other activities that will run concurrently. A link is used to connect the activities that it contains. This activity is equivalent to the concept of fork/join: all the paths within the activity are run simultaneously, and the target activity will not fire until all paths have completed.

• Link
• Use the link within a parallel activity to connect nested activities and form individual control paths. The link is used to express a synchronization dependency. In other words, it runs under a constraint because the link creates a dependency of one activity and the variables it uses on another activity. You can specify a transition condition on the link in the properties area of the BPEL process editor.

Scope activity

Use this to act as a behavioral container for one or more activities in your process.

You can also use a scope activity for enhanced dynamic behavior, by using an administrative human task to grant a user administrative privileges over the running order of the activities that are nested within the scope. Enhanced dynamic behavior is more fully supported by using a Collaboration Scope. See related topics for more information.

Sequence activity

Use this to nest a series of activities into your process that will run sequentially.

While loop activity

Use this activity to repeat one or more activities as long as specific conditions are in place. The conditions are evaluated at the beginning of the activity. Hence the activity is skipped if the condition is not met on entry.

Repeat until loop activity

Use this activity to repeat one or more activities as long as specific conditions are in place. The conditions are evaluated at the end of the activity. Hence the activity is performed at least once.

To work with a structured activity, proceed as follows: