WEB APPLICATIONS WEB PROGRAMMING AT ITS BEST

The World Wide Web is a highly programmable environment that allows mass customization through the immediate deployment of a large and diverse range of web applications, to millions of global users. Two important components of a modern website are flexible web browsers and web applications, which are both available at no expense.

Today’s websites are a far cry from the static text and graphics showcases of the early and mid-nineties: modern web pages allow personalized dynamic content to be pulled down by users according to individual preferences and settings. Furthermore, web pages may also run client-side scripts that “change” the Internet browser into an interface for such applications as web mail and interactive mapping software (e.g., Yahoo Mail and Google Maps).

Most importantly, modern websites allow the capture, processing, storage and transmission of sensitive customer data (e.g., personal details, credit card numbers, social security information, etc.) for immediate and recurrent use. And, this is done through web applications. Such features as webmail, login pages, support and product request forms, shopping carts and content management systems shape modern websites and provide businesses with the necessary means to communicate with prospects and customers. These are all common examples of web applications.

Web applications are, therefore, computer programs allowing website visitors to submit and retrieve data to/from a database over the Internet using their preferred web browser. The data is then presented to the user within their browser as information is generated dynamically in a specific format (e.g., in HTML using CSS) by the web application through a web server.

 

Web Application terms

Web browsers are software applications that allow users to retrieve data and interact with content located on web pages within a website.

Client is the application used to enter the information. It is used in a client-server environment to refer to the program the person uses to run the application.

Server is the application used to store the information.

Client-server environment is when multiple computers share information, such as by entering information into a database.

 
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How do web applications work?

The web application model has three-layers.

  • Layer I is typically a web browser or the user interface;
  • layer II is the dynamic content generation technology tool, such as Java servlets (JSP) or Active Server Pages (ASP).
  • Layer III is the database containing content (e.g., news) and customer data (e.g., usernames, passwords, social security numbers, credit card details).

The initial request is triggered by the user through the browser over the Internet to the web application server. The web application accesses the database servers to perform the requested task updating and retrieving the information lying within the database. The web application then presents the information to the user through the browser.

In more technical terms, web applications query the content server (essentially a content repository database) and dynamically generate web documents to serve to the client (people surfing the website). The documents are generated in a standard format to allow support by all browsers (e.g., HTML or XHTML). JavaScript is one form of client-side script that permits dynamic elements on each page (e.g., an image changes once the user hovers over it with a mouse). The web browser is key – it interprets and runs all scripts etc. while displaying the requested pages and content. Wikipedia brilliantly terms the web browser as the “universal client for any web application.”

What are the Benefits of a Web Application?

A significant advantage of building and maintaining web applications is that they perform their function irrespective of the operating system and browsers running client-side. Web applications are quickly deployed anywhere at no cost and without (almost) any installation requirements at the user’s end. A web application relieves the developer of the responsibility of building a client for a specific type of computer or a specific operating system. Since the client runs in a web browser, the user could be using an IBM-compatible or a Mac. They can be running Windows XP or Windows Vista. They can even be using Internet Explorer or Firefox, though some applications require a specific web browser.

Web applications can provide the same functionality and gain the benefit of working across multiple platforms. For example, a web application can act as a word processor, storing information and allowing you to ‘download’ the document onto your personal hard drive.

Web applications commonly use a combination of server-side script (ASP, PHP, etc) and client-side script (HTML, Javascript, etc.) to develop the application. The client-side script deals with the presentation of the information while the server-side script deals with all the hard stuff like storing and retrieving the information.

Types of Web Applications

With an application, all or some parts of the software are downloaded from the web each time it is run. It may refer to browser-based apps that run within the user’s web browser, to “rich client” desktop apps that do not use a browser, or to mobile apps that access the web for additional information.

Browser Based

In a browser-based web application, JavaScript instructions are contained within the web page that is retrieved from a website. Combined with the HTML code that determines the visual layout, the HTML and JavaScript on the web page are executed via the browser. Alternatively, the web page may cause the browser to launch a Java applet. Java is a full-blown programming language that is more comprehensive than JavaScript. The data for a Web application may be stored locally or on the web, or in both locations. See Java.

Client Based

Web applications may also run without the browser. A client program, which is either installed in the user’s computer or mobile device or is downloaded each session, interacts with a server on the Web using standard web protocols. This is similar to the “client/server” architecture that prevailed in companies before the Internet exploded, except that today the server is often on the Internet rather than the local network. Just like browser-based applications, the data may be stored remotely or locally. See rich client, cloud computing, ASP and SaaS.

Mobile Web App

Countless mobile apps use the Web for additional information. For example, the iOS and Android versions of this encyclopedia install all the text locally in the device but retrieve all the images from a server via Web (HTTP) protocols.

What is the Future of Web Applications?

The new push for web applications is crossing the line into those applications that do not normally need a server to store the information. Your word processor, for example, stores documents on your computer, and doesn’t need a server.

If you have seen the new Gmail or Yahoo mail clients, you have seen how sophisticated web applications have become in the past few years. Much of that sophistication is because of AJAX, which is a programming model for creating more responsive web applications. Google Apps and Microsoft Office Live are examples of the newest generation of web applications.

As the number of businesses embracing the benefits of doing business over the web increases, so will the use of web applications and other related technologies. Moreover, since the increasing adoption of intranets and extranets, web applications become greatly entrenched in any organization’s communication infrastructures, further broadening their scope and possibility of technological complexity and prowess.

For more information, please visit our web division’s website www.designtorontoweb.ca

 
 

Web Applications