Research And Implementation Of LMS System Based On Ajax

With the swift development of network communication and computer technology, web services become more and more diversified. Traditional Web technology can not fulfill the requirement of modern network due to limitation on interaction and real timing. However, Ajax framework comes into being in 2005 and becomes popular in 2006 with strong supports from Google and Microsoft. Based on XMLHTTPRequest, Ajax framework strengthens on interaction and real timing and is regarded as the standard for Web service of next generation with the title of Web2.0. To be an asynchronous communication way, Ajax utilizes the data exchange between Client-Side Scripts and Web Application. Ajax acts like a middle layer between users and Server, asynchronizing the communication between users and Server. The applications and research of Ajax have become a focus. And a lot of Ajax frameworks are coming out, promoting the application of Ajax for Web Application.This thesis is based on a LMS system named Cisco China Channels University, starting with the necessity analysis of Ajax technology, we dicuss the need of Ajax because of network delay and asynchrony. After discussing Ajax technology details, we analyze the Ajax application scene and propose the scene of suitable and not sutitable Ajax application, which guides developers using Ajax in the reasonable way.Secondly, the thesis analyzes the role and the normal architecture design of Ajax engine and gives the disadvantage of normal architecture design. From the perspective of fine grain, we propose a design programme of controller-centered Ajax engine, which makes Ajax applications easy to maintain and saves system resources.At last, under the guide of lightweight architecture the thesis gives the implementation of persistence lay, view lay, business logic lay and the integration of Ajax and WebWork on the server side. On the client side, under the controller-centered design programme of Ajax engine, the thesis gives the implementation of showing view module, user operation action processing module,web remote communication module, data analysis module and center controller module. And using the encryption ability of Ajax on the client side, the thesis gives a programme of joint encryption both on the client based on Ajax and server side, which protects LMS system.At last we give a programme of controlling the version number both on the client side and server side starting from the calling velocity and performance using programme cache of Ajax, which cache server resources and enhance the real timing by saving network traffic. The safety and the performance optimization programme are good guidance for modern Web applications and enterprise-level applications based on Ajax.