Creating standard compliant web application using Javascript, CSS, HTML and SSI

Introduction

A web application is an application where the program and data both lie on the webhost. On request by the user(Client) The program is loaded and run on the client machine and the server is used for backend data processing activity. This article will look into creating a standard compliant WEB Application using HTML, CSS, SSI and Javascript

Pro's and Con's of a web application

Advantages

Disadvantages

Easy deployment of new versions

In traditional method of program upgradation. Once bugfixes/Enhancements are done to a given script/program every user must download and install the new version. In places with strict/Inefficient system administrators, an upgrade cycle may take longer than expected and the developer has to support at least 2 or more previous versions of the program. Having a webbased version of a program enables the developer to migrate all users to the new version of the program simultaneously

Optimization of compute resources for jobs involving compute intensive backend operations

Any tool functionality can be split into 2 parts
  1. User data entry and UI handling
  2. Processing of user data and commands.
Since traditional tools perform both the operations on the user machine, each user is required to have powerful workstations for data processing aspect of his job. Having a client server architecture allows the user to have a low end machine to perform the necessary data entry operations and use a common powerful server to perform the actual computation work.

OS Independence

Traditional tools require different builds for different OS. Hence a significant development effort is spent in ensuring that
Having a browser based application enables the developer to develop once and deploy the same application across multiple platforms.

Accessible from any machine.

Tradition applications are installed and save their data either on the local machine or on a shared network drive. A user cannot access his application or data from a different machine or from outside the network.
A web based application is installed on the server and saves the data on the server. Hence such an application can be used from anywhere in the world.

Security risk

Since the data resides on a external server it can theoretically be accessed by anyone connected to the net. While adopting network security practices makes such data access practically infeasible the user should still be aware of the risks.

Non-Standard compliant browsers.

Browser wars and monopolistic practices has resulted in the users space being littered with multiple browsers with at least one major browser vendor having a grossly crippled and non standard browser which does not follow good browser behavior. Hence the developer need to duplicate most of his effort for each browser that he intends to support in order to ensure that the application works across all browsers.

Increased Bandwidth costs,(huge program/data).

An application requiring huge chunks of data to be loaded to and saved from the client machine. Or a huge application will end up jacking up the bandwidth cost.
Next Components of WEB Application: Javascript