Introduction

Event Driven UCA is a type of UCA that fire upon the occurrence of an event. Example: When a coach is submitted, the UCA is invoked.

Details

The following example shows how event driven UCAs are implemented in the process.

Let us consider the process described under 'Timed UCA' section. The process consists of 2 activities: Order entry and Results. Order Entry allows the customer to enter their details. The Result activity shows the customer-entered details for confirmation.

In addition to this process, let us construct another process called: 'Order Printing'. This process will display the customer-entered details and thus print the information.

This 'Order Printing' process action(:Allow printing the details) takes place on occurrence of an event:(when the customer confirms his entered details). This is achieved using event-driven UCA.

Step 1: Creating 'Print Order UCA Impl' general system service Select 'General Service System' under 'Implementation' section and provide a valid name for this service (say, Print Order UCA Impl). Under variables tab, create input and output variables as shown in the screen shot.

Step 2: Create 'Print Order' UCA from the 'Implementation' tab as shown in the following screenshots. Make the schedule type: On Event. Also attach the above created service to this UCA.

Step 3: Create a new process ' Example Event Driven UCA'. Attach the above created UCA to this process by changing the 'None start event' to 'Message start event'.

Add the variables needed and map them under 'data mapping' section.

Also make necessary changes to the coach to display the entered data for printing.

Now, the 'Order Printing' process is invoked when the first process 'Order creation' is completed successfully.

Result: To observe this UCA behavior, manually start the first process 'Order Creation' by clicking on 'Run Now' under the attached UCA: 'Start New Order UCA'(which is created under Timed UCA section)

This will create an instance of the first process:Order Creation

Completion of this process will automatically invoke 'Order Print' instance as seen in the screenshot: