Handling Events on Web Pages

The click events for controls on your Web page are executed if they are present in your JADE code, with the exceptions that instead of the click event, the sheetChg event is executed for a folder control on a Web page if it is present in your JADE code.

If a click event is present, the generated HTML sets up the Uniform Resource Locator (URL) to cause a click event on the control to send a request back to the JADE application.

No other event is processed, unless it is explicitly called from the click event method.

Because of HTML restrictions, the click event cannot be executed for text box controls. Excessive use of the click event significantly slows HTML thin client interaction, as each event is passed back to the JADE application for processing.

The paint event is not called when running a Web-enabled JADE application, as no JADE forms are created and displayed.

Events are supported only on Web pages accessed by using Internet Explorer 4.0 (or higher).

The transient RootSchemaSession class provides the protected allowHiddenControlEvents property, which specifies whether hidden controls on Web pages can invoke event methods. As this property is false by default, set it to true to specify that event methods can be invoked by hidden controls.

For details about handling supported event methods in controls on Web pages, see "Enabling Event Handling on Web Pages", later in this chapter.

When a request is sent to the JADE application, the Web browser waits for a reply. If the JADE code that is processed does not initiate the creation of another Web page, the form that was previously displayed and not unloaded is displayed again. If there were no previous forms, the start-up form is displayed so that the Web browser does not wait indefinitely for a response.