Web Application Generator

An application data controller can define powerful JavaScript Business Rules to perform validation and required interactions with the user. The rules are written in JavaScript to execute in the client web browser.

Application client library will create an instance of a JavaScript class enhanced with the rules defined in the data controller to handle actions in a fashion similar to server-side SQL Business Rules and C#/Visual Basic Business Rules. A rule can analyze the field values, change them, request additional information, or prevent an action from execution.

This is the example of a JavaScript business rule performing client-side validation.

// validate the data field value
if ([Country] == 'USA') {
    // tell the client library to skip the execution of update, insert, or delete
    this.preventDefault();
    // set the focus to the field "Country" and display an error message
    this.result.focus(
        'Country', 'You are not authorized to {0}, if the country ' +
        'is equal to "USA".',
        this.arguments().CommandName);
    // show an additional information in the message bar at the top of the page
    this.result.showMessage('Error trying to execute {0} command', 
        this.arguments().CommandName);
}

The implementation of the business rule is functionally equivalent to the SQL business rule performing validation on the database engine level, but does not involve a round-trip between a browser and webserver.

This screenshot demonstrates the business rule in action.

Learn to create sophisticated JavaScript Business Rules performing complex data validation and just-in-time correction of values.

Client Script actions allow execution of arbitrary JavaScript code. For example, an action with command name Client Script can select a page of data that contains a specific record in response to user actions. This example takes advantage of automatic tracking of selected records supported by the application framework.

The Employees table of the Northwind sample has a foreign key column ReportsTo that references the table itself. Code On Time generator automatically creates a master-detail relationship on the Employees page. Let’s configure an action on the Employees data controller to select a specific record in the master view.

There are two data views on the Employees page hooked to the Employees controller. Let’s tag the top view as a “master list” of employees.

Start the Project Designer. In the Project Explorer, double-click on Employees / container1 / view1 node.

Change the following properties:

Press OK to save the data view.

Next, add an action to perform synchronization of the master list with a specific EmployeeID. Right-click on Customers / container1 / view1 / Actions / ag1 (Grid) node, and select New Action.

Give this action the following properties:

Web.DataView.find('MasterList', 'Tag').sync(this.fieldValue('EmployeeID'))

Press OK to save the action. On the toolbar, select Browse button.

On the Employees page, select Andrew Fuller from the list. An Employees child data view will open underneath. Activate the context menu for Steven Buchanan and select Show in Master List option.

The master data view will move to the page that contains Steven Buchanan with the corresponding row selected. The child data view will refresh showing employees reporting to Mr. Buchanan.

Using the context menu for Robert King, select Show in Master List.

Robert King will be selected on the third page of the master view.