Eclipse Rich Ajax Platform (RAP) Live Demo

Ajax is a set of technologies, supported by a web browser, including these elements:

  • HTML and CSS for presenting.
  • JavaScript (ECMAScript) for local processing, and DOM (Document Object Model) to access data inside the page or to access elements of XML file read on the server (with the getElementByTagName method for example)...
  • The XMLHttpRequest class read or send data on the server asynchronously.
  • The DomParser class may be used
  • PHP or another scripting language may be used on the server.
  • XML and XSLT to process the data if returned in XML form.
  • SOAP may be used to dialog with the server.

The "Asynchronous" word, means that the response of the server while be processed when available, without to wait and to freeze the display of the page.

How does it works?

Ajax uses a programming model with display and events. These events are user actions, they call functions associated to elements of the web page.
Interactivity is achieved with forms and buttons. DOM allows to link elements of the page with actions and also to extract data from XML files provided by the server.
To get data on the server, XMLHttpRequest provides two methods:
- open: create a connection.
- send: send a request to the server.
Data furnished by the server will be found in the attributes of the XMLHttpRequest object:
- responseXml for an XML file or
- responseText for a plain text.

Take note that a new XMLHttpRequest object has to be created for each new file to load.

We have to wait for the data to be available to process it, and in this purpose, the state of availability of data is given by the readyState attribute of XMLHttpRequest.

States of readyState follow (only the last one is really useful):
0: not initialized.
1: connection established.
2: request received.
3: answer in process.
4: finished.

Eclipse Rich Ajax Platform (RAP) allows developers to create Rich Internet Applications (RIA) using the OSGi standard component model. The main advantage of this technology is the ability to share the same Java code base for RCP and RIA applications.

In this two-part screencast you are going to see RAP installation process, look and feel of the RAP 1.0 Demo application and creation of the simple RAP plugin.

Installation of the RAP 1.0 using the Eclipse Update Manager (01:15):

RAP 1.0 Demo application. Creation of the "Hello world" RAP plugin (02:15):