What Is Web Application Computer Science Essay

Published Date: 02 Nov 2017

Submitted by: Stella Mingle

CIS 427 − Build Internet Applications I

Professor Timothy Jones

What is a web application?

A Web application is a program that works entirely through the Internet and can potentially be accessed through multiple environments. It can be an Active Server Pages (ASP) to a Personal Home Page (PHP) file that generates different information based on the user’s input to fill-out a form in a multi-tiered application that sends queries to a database and returns information. It is an application program that is stored on a remote server and delivered over a network such as the Internet or an intranet through a browser interface (Kymin, n.d.). Web applications are coded in a language supported by JavaScript, HTML, etc. and is dependent on a common web browser like internet explorer, firefox and google chrome to render the aplication executable (Paul, 2012). There are a number of web-based applications in the market today. Most of them are free to download.

Building Web Applications:

In building web application, there are several things to consider. First is that it must be able to run on most web browsers (Clark, 2013). Different mobile browsers have different performance capabilities that could affect the output of a web application. It advisable to have some knowledge as to what browser can support the functionality that your web application’s needs. Another thing to consider is accessibility. It should be convenient to access through any browser platform and it should have the capability to maintain web applications without distributing and installing software on many different client computers (Hughes-Croucher, 2008). When you design Web applications, you should consider the needs of all potential users. Creating Web applications involves the integration of numerous technologies and requires different approaches than traditional applications.

Web applications typically use a combination of client-side script and server-side script to develop the application. There are two main categories of scripting, coding and programming when creating Web Applications; the client-side script deals with the presentation of the information while the server-side script deals with all the data storage and retrieving of information. Client Side Scripting is the program that is interpreted by browsers. Client Side Scripting can be generally viewed by any visitor to a site (Matthews, 2011). Client-server technologies such as JavaScript, HTML (HyperText Markup Language), Ajax (Asynchronous JavaScript and XML), CSS (Cascading Style Sheets), and jQuery (JavaScript Framework Library - commonly used in Ajax Development) are used to bring about dynamic content to web applications.

Server Side Scripting is the type of code that is executed or interpreted by the web server. Server Side Scripting is neither viewable nor accessible by the general public. Some of the common technologies used include PHP (very common Server Side Scripting language - Linux / Unix based Open Source - free redistribution, usually combines with MySQL database); Zend Framework (PHP's Object Oriented Web Application Framework); ASP (Microsoft Web Server (IIS) Scripting language);ASP.NET (Microsoft's Web Application Framework - successor of ASP); Python (general purpose high-level programming language and Server Side Scripting language - free redistribution). Google Apps, Microsoft Office Live, and WebEx, WebOffice are examples of the newest generation of web applications. (Priss, n.d.)

Elements of a Web application:

Most Web applications make use of the following: forms, content, hyperlinks, components, loops, redirection and server-side actions.

Content

Information presented in a web application usually have elements that include text forms, graphics, music or video files. Content can be presented on either static HTML pages or on a dynamically generated by an ASP page. Content elements usually have one well-defined entry point with links to other pages (Microsoft Library, 2013).

Hyperlinks

Hyperlinks are primarily created to facilitate movement of an application to other pages or parts of the same page. Navigational controls, site maps, form buttons, anchors, form buttons and tool bars are all examples of hyperlinks. http://www.pb.com/assets/US/images/Microsite/email-marketing-software/Learning-Center/email-campaign-creation/add-hyperlinks-and-images-in-email/email-template-designer-editor--Jpeg-notResized.jpg

Figure 1: Example of Hyperlinks application Source: Google.com

These elements often appear by itself in their own browser frame and control the navigation throughout the site. They can also appear as a table of contents or separate index page, which is replaced once a link is selected (Microsoft Library, 2013). Hyperlinks represent a user choice, very much like a menu option does in a stand-alone.

Components

A component is any programming code that provides logical information that can be used as a separate component or in combination with other components throughout the application. The scope and break-down of responsibility distinguishes components from other application elements. Components can generate content or provide server-side logic. (Microsoft Library, 2013).

Forms

Figure 2: Example of Forms online. Source: Google.com

A form is a document that includes markup, normal content, markup, special elements like checkboxes, radio buttons, menus, etc. They are often used to collect information about the user. The output from a form depends on how it is design. The results may change when it is submitted, based on the user input. Forms can be linked together consecutively to create "Form wizards." Client-side or server-side actions usually process these forms. The standard method of interacting with Web pages is in the HTML format. Forms can contain any number of inputs, including text entry, command buttons, "radio" selection controls, and check boxes. Forms can be as simple as a single button, or they can contain a complex layout of client-side controls. A Web page can have several form structures, each with its own logical process to perform when the form is submitted. (Gamer, 2006) http://publib.boulder.ibm.com/infocenter/btt/v6r1m2/topic/com.ibm.btt.sample_applications.doc_6.1.2/doc/images/multi_7.JPG

Figure 2 above, is an example of and input form on the web. Most web sites provide security applications by requiring its users to log on to the Web application and input a user name and password. To accomplish this task, a simple HTML page with two text fields and a "Login" button in an HTML form is created.

Loops

Most programming relies on the capability to repeat a number of lines of a program code based on a condition or a counter. This is achieved by using loops. Loop pages are ASP pages that repeat itself in order to present different result, depending on the user’s input. For example, a page might select content based on how many times a web site had been viewed.

Redirection

A redirection page or script can perform logic to branch the flow of the application. Although it doesn't actually perform a redirect, a page containing a frameset can also be considered a redirection page, since it causes other pages to load. Redirection is usually more adaptable and flexible if implemented as a separate ASP page. A typically a redirection page is used when a website is being updated to a new domain or provider. Below is an example of a script to redirect a website using HTTP server programming (Michigan State University, P-A & Computing Services Department, n.d.).

Example:

Redirect  /path-of-file-to-be-redirected  URL-of-page-to-go-to

Action

Action in this case means how an application responds to a user’s action. When the user submits a form, for example, the application processes the form. Action pages perform business logic processes, such as data entry, calculations, or administrative functions. Action or processing can occur both on the client side and on the server side, and can also be used to generate content like confirmations or error messages. Figure 3 below illustrates the flow of information when accessing a web application.

FIGURE 3: Illustrates how an application responds to user action on the web.

The figure above shows how the initial request from a user is triggered through the browser; carried over the Internet to the web application server. The web application accesses the databases 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.

Benefits of Web Applications

Today's web applications have substantial business impact on the way companies and consumers conduct business. Companies who are not utilizing today’s technology will have to reinvent themselves in order to compete in today's online business and global marketplace. More and more business processes these days are moving to the internet.  Web-based applications offer numerous advantages, such as instant access, automatic upgrades, and collaboration opportunities through online meeting or conferencing. Many popular websites including registration, retail store fronts and user forums are built using web database applications. Web database applications provide security, data processing, data storage and data authentication, and the ability to update Web page content dynamically. There are many software tools available to build Web database applications using a variety of programming languages including PHP, Zend Framework , ASP, ASP.NET , and Python (Paul, 2012).

Web applications allow companies to deliver complex programs with very little time since all you need is a web browser and a URL to the application. In some instances, employees will be able to access the application almost immediately. Data are store on the server, so users does not need a lot of extra hard drive space to install and use web applications. Other business advantage includes improved control of information. Using electronic forms meant that reports could be tracked on throughout the entire process in the system, making it easy to verify and audit back-end information. It also enables businesses to cut cost and reduced labor expenses. Since online system requires fewer forms, less manual applications are needed, and hence fewer resources.