Before You Begin

This 15-minute tutorial shows you how to create commonly used business rules for business objects using Oracle Visual Builder.

Background

Most Oracle Visual Builder applications require rules for business objects to execute business logic that deals with the data. These rules can range from a simple validation expression on a field, to more complex rules that validate objects and fields and that trigger actions based on events or on field changes. You can also create and call functions on objects.

In this tutorial, you'll create some business rules for an application that keeps track of business expenses.

Although this tutorial doesn't have any prerequisites, you may want to complete the tutorial Create a Web Application in Oracle Visual Builder first, to become familiar with creating business objects.

What Do You Need?

• Access to Oracle Visual Builder
• A supported browser

Create an Application and a Business Object

1. In the web browser, log in to Oracle Visual Builder.
2. On the Visual Applications page, click New.

   

3. In the Create Application dialog box, enter:
   • Application Name: Expense Tracker
   • Description: Tutorial application

   The Application ID text field is automatically populated as you type, based on the Application Name. The Application template field is set to Empty Application.

4. Click Finish.

   The application is created and opens on the Welcome page. You'll first create a business object.

5. Click the Business Objects tile.

   

   The Business Objects pane of the Navigator opens.

6. Click the + Business Object button.

   

7. In the New Business Object dialog box, enter Expense in the Name field. Expense is filled in automatically for the Display Label field. Click Create.
   

   Now we need to add a new field to the basic set of fields that was populated for our business object.

8. Click the Fields tab, then click the + button and Field.
9. In the dialog box, enter:
   • Label: Amount
   • Field Name: amount (automatically populated)
   • Type: Number

   Click Create Field.

   

10. Create the following additional fields:

    Field Name	Type
    Description	String
    Date Incurred	Date
    Expense Type	String
    Approved	Boolean

    When you've finished, the fields are displayed as follows:

    

Create a Field Validator

A field validator is a constraint that you can place on any custom field (that is, a field you created yourself). The expression or script that defines the rule must return a Boolean value.

1. Click the Business Rules tab, then click the Field Validators tab.

   

2. Click + New Field Validator. In the Create Field Validator dialog box, enter or select:
   • Validator Name: Amount Is Greater Than Zero
   • Field: Amount
   • Error Message: Enter an amount greater than zero.

   Click Create Field Validator.

3. On the page that opens, mouse over newValue under Field Values and click the Insert arrow, then add > 0 in the text area to create the validator expression.

   

4. Click the Field Validators tab again to return to the Field Validators page. The field validator is created and active.

   

Create an Object Trigger and a Condition

An object trigger defines a sequence of actions that starts when a specific event occurs, such as inserting or updating a record. When you create an object trigger, you specify the triggering event and the actions that are then executed. You can refine the sequence so that actions are executed only when some criteria are met. A single object trigger can define multiple criteria and multiple actions.

1. Click the Object Triggers tab.
2. Click + New Object Trigger.
3. In the Create Object Trigger dialog box, enter Approve Expenses in the Trigger Name field. Select the Before Insert option from the Start Event list. Click Create Object Trigger.

   

4. In the Trigger Designer, click the + sign (Create New Criteria).

   

5. Select Execute Conditionally from the Choose Criteria Type dialog box to bring up the Criteria pane on the right. Note: If the Criteria pane isn't shown, click on the upper right side of the Trigger Designer.
6. In the Criteria Name field, enter Amount <= 200.
7. Click Add Conditions.
8. On the Build Conditions page, enter or select:
   • Select Field: Amount
   • Select Operator: less than or equals
   • Fill in the value: 200

   

9. Click Done.

Add Actions for the Condition

1. Click the Add Actions box (not the + sign).

   

2. In the Action Group pane, enter Auto-approve Expense in the Action Group Name field and click Add Actions.

   

3. On the Configure Actions page, drag Update Record into the Then Do Something Else action builder area.

   

4. With Expense selected under Data to Update, click Add Value Update.
5. Select Approved from the Value Updates drop-down list, and select true from the drop-down list of values.

   

6. Drag Send eMail Notification into the Then Do Something Else action builder area, below Update Record.
7. Click Create next to the Select a Template drop-down list.
8. On the eMail Template page, select Save for this Action only from the drop-down list.
9. In the Subject and Body field, enter Your expense of and then click to on the far right side of the field to insert a parameter.
10. Replace Parameter1 inside the brackets with amount. Then enter is approved.
11. In the email body section, enter Your expense is approved. and click Save.

    

12. In the Send eMail Notification section, enter your email address in the Recipients field.
13. From the drop-down list next to the Value field, select Expression.

    

14. In the Enter Expression dialog box, hover over Amount and click the Insert arrow to enter amount in the text area.

    

15. Click OK to return to the Configure Actions page. The Send Email Notification action should look something like this.

    

16. Click Done. The actions you created appear in the action group box for the condition.

Create a Second Condition and Add Actions

1. In the Trigger Designer, click the + sign (Create New Criteria).
2. Select Execute Conditionally from the Choose Criteria Type dialog box to bring up the Criteria pane on the right. Note: If the Criteria pane isn't shown, click on the upper right side of the Trigger Designer.
3. In the Criteria pane, for the Criteria Name field, enter Amount > 200.
4. Click Add Conditions.
5. On the Build Conditions page, select or enter:
   • Select Field: Amount
   • Select Operator: greater than
   • Fill in the value: 200
6. Click Done.
7. Click the Add Actions box (not the + sign).

   

8. Enter Send Email about Pending Approval in the Action Group Name field and click Add Actions.
9. Drag Send eMail Notification into the Then Do Something Else action builder area.
10. Click the Create button next to the Select a Template drop-down list.
11. On the eMail Template page, select Save for this Action only from the drop-down list.
12. In the Subject and Body field, enter Your expense of and then click to insert a parameter.
13. Replace Parameter1 inside the brackets with amount. Then enter is waiting for approval.
14. Click Save.
15. Enter your email address in the Recipients field.
16. From the drop-down list next to the Value field, select Expression.
17. In the Enter Expression dialog box, hover over Amount and click the Insert arrow to enter amount in the text area. Click OK to return to the Configure Actions page.
18. Click Done.
19. You've now completed the trigger creation. Click the Object Triggers tab. The trigger is now active.

    

Test the Field Validator

For this tutorial, you will use the Data tab to create expenses and test the business rules. In a typical web or mobile application, you would create pages to enter data.

1. Click the Data tab and click + Row.

   

2. In the Add Row dialog box, enter:
   • Amount: -5 (a negative number)
   • Date Incurred: Select today's date (the default)
   • Description: Coffee
   • Expense Type: Dining

   Click Add row.

   The error message you specified is displayed in the dialog box. The validator works correctly.

   

3. Click Cancel.

Test the Trigger

1. Click + Row.
2. In the Add Row dialog box, enter:
   • Amount: 199 (less than 200)
   • Date Incurred: Select today's date
   • Description: Train tickets
   • Expense Type: Travel

   Click Add row. The new row appears in the table, with the Approved field set to true.

3. Click + Row again.
4. In the Add Row dialog box, enter:
   • Amount: 399 (greater than 200)
   • Date Incurred: Select today's date
   • Description: Airfare
   • Expense Type: Travel

   Click Add row. The new row appears in the table, with the Approved field set to false.

5. View your email. You should have received two messages, one with the auto-approval message and one stating that the expense is waiting for approval.