The Web DataWindow is a thin-client DataWindow implementation for Web applications. It provides most of the data manipulation, presentation, and scripting capabilities of the PowerBuilder DataWindow without requiring any PowerBuilder DLLs on the client.
The Web DataWindow supports a subset of the PowerBuilder DataWindow events and methods, including dynamic modification of the DataWindow object. The user can modify and update data. Composite, Graph, OLE, TreeView, and RichText presentation styles and controls are not supported.
The HTML Web DataWindow works in most browsers, but the appearance of the generated HTML is usually best in Internet Explorer. Generated HTML can be dynamically optimized for Netscape or Internet Explorer, or scaled back to handle older browsers. The XML Web DataWindow and the XHTML Web DataWindow require the lastest browser technology. For information about supported browsers, see “Browser requirements for the XML Web DataWindow”.
A component server and a dynamic page server work together to generate a client control with data and include it in a Web page. Each time the user requests a new page of data, updates data, or inserts or deletes rows, the server gets a request to generate a new page. Depending on how state is managed, the component might retrieve data each time it is called, causing added load on the server.
The Web Target interface in PowerBuilder provides the Web DataWindow DTC that you can use to develop Web DataWindows without hand coding. You can also write your own server-side scripts to create Web DataWindows using the component server’s API. You can write the scripts for interpretation by a specific page server type (Active Server Pages or JavaServer Pages). For Web site targets, you can use the Web Target object model to write server scripts that are type-neutral—the scripts can be deployed to Active Server Pages.
When you use the Web DataWindow DTC on a 4GL Web page, server-side events are available and page variables can enhance the dynamic capabilities of your Web application. You cannot hand code a Web DataWindow on a 4GL Web page.
For information about the Web DataWindow, see Chapter 6, “Using the Web DataWindow.” For information about the Web DataWindow DTC, see Working with Web and JSP Targets.
