Creating the Front End of a Search Engine with AJAX. Creating the Front End of a Search Engine with AJAX(Page 1 of 5 ) Introduction When it comes to developing AJAX-driven applications, certainly there’s a plethora of possibilities that can be considered as potential targets.
This is especially true if the web project that is going to be deployed may gain some kind of benefit from using this type of technology. In fact, there’s no point in using AJAX only because it’s cool, or because in the last few months it has became your favorite web development toy. Logically, there must be a strong reason for utilizing it, particularly considering that the most critical parts of your application shouldn’t depend on JavaScript to work properly. However, with the huge proliferation of AJAX-based programs, there are specific situations where this technology can greatly improve the functionality of a given application, and at the same time provide users with a richer experience when they’re using it. Ready to learn how to build a search engine with AJAX? AJAX: The Easy Way @ LINUX.SYS-CON.COM. Putting AJAX functionality into your Web application can be a daunting task when you're first learning AJAX.
After all you're a Java programmer not a JavaScript programmer. It can also be very frustrating having to learn how the different browsers handle XMLHttpRequests. It's been reported, however, that Internet Explorer 7 will support native XMLHttpRequests rather than requiring the developer to make ActiveX requests. This will make a Web developer's life a lot easier. For Java Developers there are a number of different frameworks/libraries that hide most of the complexity of developing AJAX-enabled Web applications. DWR is an Open Source Java library, distributed under the Apache License version 2, that lets JavaScript call Java methods as if they were running in the browser, when in fact they're running on the server.
There are a number of different ways that you can use DWR, and the extensive documentation shows most of them. JSON Basics. JSON Basics(Page 1 of 5 ) Although RFC 4627 marks a JSON milestone, it appears that it had already been discussed among the JavaScript cognoscenti.
JSON is equally, or even more suited, for data exchange than XML, which was originally considered to be the ideal wire friendly format. What is JSON? So what is JSON? It's an acronym you might have started seeing in greater frequency on the Internet. You can read more about JSON in RFC 4627. Building the User Interface for a Web Site Indexing Application. Periodic Refreshing for the Browser-Server Dialogue. (Page 1 of 4 ) {*style:<i> </i>*} Devi's coding up a ticket sales web site. For each event, she wants to keep the browser updated with the number of tickets remaining. Thus, she introduces a timer so that every 30 seconds, it calls a web service to pull down the latest sales stats. How can the application keep users informed of changes occurring on the server?
The state of many web apps is inherently volatile. HTTP requests can only emerge from the client. One way to keep the browser updated is (Chapter 6), but, as the "Alternatives" section for that pattern explains, it's not always ideal. The solution makes use of the browser's (Chapter 7) capabilities to provide a means of keeping the user informed of latest changes. In its simplest form, a loop can be established to run the refresh indefinitely, by continuously issuing (Chapter 6): setInterval(callServer, REFRESH_PERIOD_MILLIS); The period between refreshes would ideally be zero, meaning instant updates. Creating the Front End of a Headlines System with AJAX. Creating the Front End of a Headlines System with AJAX(Page 1 of 5 ) A downloadable file for this article is available here.
Introduction These days, the number of websites that use AJAX for the driving technology to build richer Web applications is really remarkable. To see an illustrative example in action, you must take a look at the progressively popular Google's Gmail service, which demonstrates how an excellent implementation of JavaScript-based HTTP requests can be used for creating a full-featured web-based email application. However, there's no need to examine only the Gmail service to realize the deep impact that AJAX-driven applications have had in the vast terrain of Web development.
Speaking more specifically, there are numerous websites (most of them are online newspapers) that use a huge variety of AJAX-based systems to display their breaking news and headlines on the front page.