Datasheet

Chapter 1: AJAX Technologies
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As this figure shows, the AJAX engine consists of the following three main components:
❑ Scheduler: The scheduler uses AJAX technologies such as XMLHttpRequest to send data to and
receive data from the server in an asynchronous fashion. As the name suggests, the scheduler
schedules and makes the client requests to the server.
❑ Renderer: The renderer component of the AJAX engine uses DHTML to dynamically update
only those portions of the current page that need refreshing without re-rendering or re-loading
the entire page.
❑ JSON/XML Serializer: The client and server exchange data in JSON or XML format. The JSON/
XML serializer has two main responsibilities:
❑ Serialize the client data, which are JavaScript objects, into their JSON or XML representa-
tions before these objects are sent to the server
❑ Deserialize JavaScript objects from the JSON or XML data received from the server
Ajax Engine
Renderer
(DHTML)
JSON/XML Serializer
Internet
Scheduler
(XMLHttpRequest)
Figure 1-2
rendered all over again to display the new information. AJAX changes all that. As you can see in
Figure 1-2 , the Ajax engine takes complete control over the client-server communications and the
rendering of the new information to ensure that these communications and renderings do not interrupt
the user interactions.
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