A Callback element is a component plugged in to Elixir Report Designer to allow specialized rendering. Java code can be plugged into the render engine to handle specific data formats. As an example, Elixir Report Designer ships with HTML and RTF. Others may be available or already installed in your configuration. We will focus on HTML here, because that is available in all installations. Currently HTML Callback supports HTML version 3.2 (with some extensions).

Select and place the Callback element in the report layout. The Callback Wizard appears listing the component types that are available.

When you select the HTML and click on the Next button the screen allows the specification of the control source - it might be HTML read from a file (or URL), literal HTML, or HTML from a datasource. If you select Literal as the Control Source type and enter the following script:

<h1>This is a test report</h1>

Then on rendering the report, the above sentence is displayed as a Level 1 heading. Similarly all HTML 3.2 tags are interpreted into text and displayed when the report is rendered. The HTML render component uses Sun's HTML rendering technology, so support is limited to the features Sun's renderer supports.