Technology

Technology papers and blog posts

Database Application

The use of a database web application has many benefits over using static web pages for delivery of content to users. Asynchronous HTTP requests are the prominent reason for such a shift. The following explains the advantages in more detail.


ASP.NET

ASP.NET is one of a family of software packages known as application servers. An application server is a piece of software that is installed on a web server to create a dynamic application platform. The World Wide Web includes many clients and servers that are connected over the Internet. Technically speaking they communicate using a protocol called TCP/IP. This is the protocol that connects all the computers in the whole world together. When these computers talk to each other they exchange messages in a format known as HTTP which stands for hypertext transfer protocol. This sort of communication is used whether working with a static website that is a website that delivers static fixed web pages or a dynamic web application such as those that are supported by ASP.NET. A client starts the process by sending a request in the HTTP format the client requests a web resource which might be a web page, an image file, or text files that contain JavaScript or Cascading Style Sheet code known as CSS. The server responds by sending back the resource that has been requested

ASP.NET is an object-oriented platform that allows you to select from multiple programming languages to create a dynamic web based application, where the client makes a standard HTTP request and the server responds by constructing HTML dynamically and sending that content back to the client. These pages can include JavaScript code, Cascading Style Sheets, image files, and everything else that might be included in a static web page.

In the dynamic environment the application server software is installed on the same computer as the web server. The application server can communicate with the database and with other server resources. Again the web client sends an HTTP formatted request, the web server talks to the application server, the application server talks to the database and other network resources, and then it is up to the web server to construct an HTML formatted response. This is then sent back to the client. The important thing here is that the web browser does not know that there is an application server at work and therefor does not need any additional software.

Appropriate Uses of Java and JavaScript 1

Java

Java is an object-oriented programming language primarily designed for use in the Internet’s distributed environment, and was created with the intention of bringing the “look and feel” of the C++ language, but in a easier-to-use form. Java is considered to be an extremely “portable” language, as compiled Java source code (or bytecode, as it is known) can be run on any computer or device that can use the Java Virtual Machine (JVM) -- this includes nearly all types of computers, laptops, tablets, smartphones, Blu-Ray players, and many other types of electronics that we use on an everyday basis.

According to the Rouse (2007) article, “The code is robust, here meaning that, unlike programs written in C++ and perhaps some other languages, the Java objects can contain no references to data external to themselves or other known objects. This ensures that an instruction cannot contain the address of data storage in another application or in the operating system itself, either of which would cause the program and perhaps the operating system itself to terminate or ‘crash.’ The Java virtual machine makes a number of checks on each object to ensure integrity.”

Below is an example of Java source code for a very basic “Hello World” application:


1	/*
2	Java Hello World example.
3	*/
4	 
5	public class HelloWorldExample{
6	 
7	  public static void main(String args[]){
8	 
9	    /*
10	    Use System.out.println() to print on console.
11	    */
12	    System.out.println("Hello World !");
13	 
14	  }
15	 
16	}
17	 
18	/*
19	 
20	OUTPUT of the above given Java Hello World Example would be :
21	 
22	Hello World !
23	 
24	*/
					

Appropriate Uses of Java and JavaScript 2

JavaScript

JavaScript is a scripting language developed by Netscape that allows Web developers to add interactivity into their Web sites. While JavaScript and Java share many similarities, in terms of structure and features, it was developed entirely separate. JavaScript interacts with HTML code, and can be viewed in most any modern browser. JavaScript can be used to add a number of different features to a Web site, such as forms and input validation, or it can also be used to change HTML content, images, and styles.

Below are some examples of JavaScript code:

Variables


/*
JavaScript Variable Example.
*/
var x = 5;
var y = 6;
var z = x + y;			
					

Arrays


/*
JavaScript Array Example.
*/
var cars = ["Saab", "Volvo", "BMW"];
document.getElementById("demo").innerHTML = cars[0];						
					

Document Object Model (DOM)

DOM is a World Wide Web Consortium (W3C) standard

The DOM is a World Wide Web Consortium (W3C) standard, used for accessing HTML and XML documents.

According to W3CSchools.com "the W3C Document Object Model (DOM) is a platform and language-neutral interface that allows programs and scripts to dynamically access and update the content, structure, and style of a document."

DOM consists of three separate parts: Core DOM -- the standard model for structured document, XML DOM -- the standard for XML documents, and HTML DOM -- the standard for HTML documents. XML DOM is used to define the objects and properties of all XML elements, as well as the methods to access them, while HTML defines all objects and properties of HTML elements, as well as the methods to access them.