Working with Exclusive Gateways

The following scenario simulates a simple leave approval business process, in which an employee fills a form and submits the leave request to the manager and the manager approves or rejects it. The process ends if the manager approves the request. Otherwise, if the manager rejects it, the employee will be able to resend the leave request by adjusting it. 

Importing artifacts 

If you did not try the Working with User Tasks tutorial yet, follow the steps below to import its artifacts as you will be extending on that.

1. Download the pre-packaged project and extract it to a preferred location. This contains the artifacts of the Working with User Tasks tutorial. 
2. Open WSO2 Integration Studio.
3. Click File, and click Import. 
4. Expand the WSO2 category, select Existing WSO2 Projects into workspace and click Next.
5. Click Browse, select the file you extracted and upload it.  
6. In the Package Explorer, double click on the name of the BPMN diagram to view the BPMN artifacts you imported.
   

Creating new artifacts

The next step of the process is defining the logic for the employee to adjust and resend the leave request if it gets rejected and for the process to end if the request gets approved. Follow the steps below to implement this logic using BPMN artifacts.

1. Right click on the connection arrow, which connects the Review leave request User Task to the End Event and click Delete.
   
   
2. To add a decision making notation to indicate these two actions, hover your mouse pointer over the Review leave request User Task and click on the Exclusive Gateway icon. 
   
   
3. Hover your mouse pointer over the Exclusive Gateway, and click on the arrow icon (i.e., the Create Connection option) and connect the Exclusive Gateway to the End Event.
   
   
4. Drag and drop another User Task to the diagram.
   
5. Click on the User Task, and change the value of the Name field to Adjust vacation request in the General section of the Properties tab. 
   
   
   
6. Hover your mouse pointer over the Exclusive Gateway, and click on the arrow icon (i.e., the Create Connection option) and connect the Exclusive Gateway to the Adjust vacation request User Task.
   
   
   
7. Hover your mouse pointer over the Adjust vacation request User Task, and click on the arrow icon (i.e., the Create Connection option) and connect the Review leave request User Task to the End Event.
   
   

Configuring the Exclusive Gateway

1. Click on the Exclusive Gateway and enter the following details in the  General tab of the Properties tab.

   • Id:requestApprovedDecision

   • Name:Request approved?

   
   
   Now, let's add the decision logic that specifies that the process should proceed to the End Event if approved.
   

2. Click on the arrow, which connects the Exclusive Gateway to the End Event and enter ${vacationApproved == 'true'} as the value for Condition in the Main config  section of the Properties tab.

   vacationApproved is the ID of the enum field you added in the Review leave request User Task.

   
   Now, let's add the decision logic that specifies that the process should proceed to the Adjust vacation request User Task if rejected.
   

3. Click on the arrow, which connects the Exclusive Gateway to the Adjust vacation request User Task and enter ${vacationApproved == 'false'} as the value for Condiiton in the Main config  section of the Properties tab.
   
   
   

Configuring the Adjust vacation request User Task 

1. Click on the Adjust vacation request User Task and set the Assignee as admin in the Main Config section of the Properties tab. 
2. Click Form in the Properties tab of the Adjust vacation request User Task.

3. To create the application form to resend the leave request, click New and add a new entry for each of the following fields. 
   

   id	Name	Type	Date Pattern	Readable	Writable	Required	Form Values
   numberOfDays	Number of days	long	-	true	true	true	-
   startDate	First day of holiday (dd-MM-yyyy)	string	dd-MM-yyyy hh:mm	true	true	true	-
   vacationReason	Reason	string	-	true	true	true	-
   employeeName	Name of employee	string	-	true	true	true	-
   resendRequest	Resend vacation request to manager?	enum	-	true	true	true	Id: true
   							Name: Yes
   							Id: false
   							Name: No

   
   

   The properties of the Form should look like the following:
   

   

4. Save all the artifacts that you created in WSO2 Integration Studio.
   The model is now complete as the necessary logic has been applied.