Web 2.0技术与jQuery和Ajax外文翻译资料

Web 2.0 Technologies with jQuery and Ajax

Cornelia Gyouml;rouml;di1, Robert Gyouml;rouml;di1, George Pecherle2, Tamas Lorand,3 Roșu Alin4

1Associate professor Phd. Eng.; 2Phd student ;3Student Department of Computer Science, Faculty of Electrical Engineering and Information Technology, University of Oradea, Str. Universitatii 1, 410087, Oradea, Romania, E-mail: cgyorodi@uoradea.ro, rgyorodi@rdsor.ro, gpecherle@uoradea.ro, tlorand2004@yahoo.com, 4S.C.Trident SRL Timişoara

Abstract. The development of a web 2.0 portal using Ajax and jQuery techniques. This paper describes the development of a web portal using technologies like PHP, jQuery and Ajax. Regular web portals simply use PHP and MySQL, which is not enough to provide the interactivity the user needs from a web portal. jQuery technique is designed to change the way you write JavaScript, because it is very compact and easy to use and understand. jQuery is also very popular being used by Google, IBM, NBC, Amazon, Wordpress and many others. Ajax technique is used to increase responsiveness and interactivity of the web pages achieved by exchanging small amounts of data laquo; behind the scenes raquo; so that the entire web pages do not have to be reloaded each time there is a need to fetch data from the server.

Keywords: web portals, JavaScript, jQuery, Ajax, PHP, MySQL, HTML, CSS, DOM, XML

I. INTRODUCTION

Web 2.0 seems to be like Pink Floyd lyrics: “it can mean different things to different people, depending on your state of mind” [1]. So Web 2.0 for some people it means moving some of the thinking client side so making it more immediate, but the idea of the Web as interaction between people is really what the Web is. That was what it was designed to be as a collaborative space where people can interact [2]. In fact, it means using the standard which has been produced by all the people working on Web 1.0. It means using the document object model, it means for HTML and SVG and so on, its using HTTP, so its building stuff using the Web standards, plus Java script of course.

According to Tim OReilly, 'Web 2.0 is the business revolution in the computer industry caused by the move to the internet as platform, and an attempt to understand the rules for success on that new platform' [3].

Some technology experts, notably Tim Berners-Lee, have questioned whether one can use the term in a meaningful way, since many of the technology components of 'Web 2.0' have existed since the beginnings of the World Wide Web.

A web portal is a site that provides a single function via a web page or site. Web portals often function as a point of access to information on the World Wide Web [14]. The first attempt is to write the web portal in PHP and MySQL only, however the whole idea of the web portal is to be interactive and provide the accesibility that most usersneed.

This interactivity can be achieved in a very easy and fashionable way, by using a compact language such as jQuery. jQuery technology is a lightweight JavaScript library that emphasizes interaction between JavaScript and HTML. It was released in January 2006 at BarCamp NYC by John Resig. It is free and open source software [15].

jQuery works closely with Ajax, whose main characteristic is to load data on a web page without reloading the entire page. The advantages of Ajax include Bandwidth usage, and separation of data, format, style and function [6]. One downside is that for search engine optimization of web sites using Ajax, you have to provide public sitemaps.

II. WEB 2.0 AND THE RELATED TECHNOLOGIES

Democracy and Ajax are the core elements of 'Web 2.0' [4]. The shortest definition of it is: 'Web 2.0 is made of people' [5]. The key aspects of web 2.0 are:

- The Web and all its connected devices as one global platform of reusable services and data

- Data consumption and remixing from all sources, particularly user generated data

- Continuous and seamless update of software and data, often very rapidly

- Rich and interactive user interfaces

- Architecture of participation that encourages user contribution [5].

Fig. 1. The Web 2.0 Architecture

Ajax, (AJAX - shorthand for 'Asynchronous JavaScript and XML,') is a development technique for creating interactive web applications. The intent is to make web pages feel more responsive by exchanging small amounts of data with the server behind the scenes, so that the entire web page does not have to be reloaded each time the user requests a change. This is intended to increase the web pages interactivity, speed, and usability. More information about Ajax you can find in [6], [7] or [8]. The XHR (XMLHttpRequest) object is the core of the Ajax engine. It is the object that enables a page to get data from or post data to the server as a background request, which means that it does not refresh the browser during this process. Below we present how the classic and the AJAX web applications work (Fig.3).

jQuery is actually an open source JavaScript library that simplifies the interaction between HTML and JavaScript. It is ideal for prototyping, it is completely unobtrusive, uses CSS to layer functionality and it has an easy to separate behavior.

Dave Methvin, Chief Technology Officer at PC Pitstop (a well known community where you can get computer help) says: “You start with 10 lines of jQuery that would have been 20 lines of tedious DOM JavaScript. By the time you are done its down to two or three lines and it couldnt get any shorter unless it read your mind” [22].

The focus of jQuery can be resumed by “finding some elements” then “doing something with them” [19]. You can find below an example of how a block of text in HTML can be made to fade in with a “slow” effect (Fig. 3).

Fig. 3. The

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