Create an Event Choice Node in Your Business Process
Create an Event Choice node at a point in a business process at which the business process should wait to receive multiple events. The events can include:
- Receiving messages from clients.
- Receiving messages from resources, such as a database, a JMS queue, an EJB, and so on. (A business process interacts with resources using controls.)
- A Timer event. The timer starts when the execution of the business process reaches the Event Choice node and pauses to wait for an event.
To support these types of events, the first node on a branch can be a Client Request, a Control Receive, or a Timer node. The flow of execution proceeds along one branch in an Event Choice node; the branch containing the event that happens first.
To create an Event Choice node:
- On the Application tab, click the business process (JPD file) you want to design.
Your business process is displayed in the Design View.
- If the Palette is not visible in WebLogic Workshop, choose View —> Windows —> Palette from the WebLogic Workshop menu.
- Click
Event Choice in the Palette. Then drag and drop it onto the business process in the Design View, placing it on the business process at the point in your business process where you want to handle the receipt of multiple events.
The Design View is updated to contain a representation of the Event Choice node as shown in the following figure:
Note the following characteristics of the Event Choice node:
- An Event Choice node is, in effect, a group of nodes. You can view and edit the properties of your Event Choice node by clicking the outline or label (name) of the group to select it, then viewing the group properties in the Property Editor. To learn about groups, see Grouping Nodes in Your Business Process.
- By default, Event Choice nodes are created with two branches. Click
to create additional branches. A new branch is added on the left or right of the existing branches.
- You can add additional nodes to the paths in your Event Choice group to specify the events executed at run time. The empty nodes (labeled Starting Event) at the start of each branch indicate that only certain nodes are allowed at these locations: specifically, you can add only Client Request or Control Receive nodes at the start of the branches.
- A Timer branch is not included by default. You can add one Timer branch to your Event Choice group. To do so, right-click the Event Choice group and select Add Timer Branch—a Timer branch is added as the right-most branch in an Event Choice group. You can only add one Timer branch per Event Choice group.
Note: The Timer branch of an Event Choice node is not available when the node group is used as the Starting Event of a business process. To do timed starts of a process, you have to use a Message Broker subscription in tandem with a Timer event generator. For more information about Message Broker subsrciptions and Timer event generators, see Using Integration Controls.
- By default, the group is named Event Choice, and each branch is labeled Message Event, Add Branch, or Timer Event depending on the type of branch. You can change the names by double-clicking them and entering a new name.
-
indicates that the design of this node is incomplete. When you complete the design of the node,
is replaced by
. An Event Choice node is complete when all starting events have been specified.
- To save your work, select File —> Save.
Related Topics
Design Your Event Choice Group
Comparing Parallel Nodes and Event Choice Nodes
Handling Exceptions
Adding Timeout Paths
Adding Message Paths