Web Application Development: Design, Scripting Languages & Security

This report provides a comprehensive overview of web application development, covering essential concepts such as web application functions, advantages, and lifecycle models like Scrum and Extreme Programming. It critically compares server-side and client-side scripting languages, highlighting their respective functionalities and roles in web application architecture. The report also examines web security, emphasizing the importance of confidentiality, availability, non-repudiation, and integrity, and offers recommendations for security improvements. Furthermore, it delves into the design aspects of web applications, synthesizing client-side and server-side functionalities and applying database design principles using use case diagrams and entity-relationship diagrams (ERD). Finally, it evaluates alternative designs and solutions, such as WordPress, Joomla, and Drupal, to meet specific requirements outlined in a case study, discussing their advantages and disadvantages in the context of web application development. Desklib provides students access to this and other solved assignments.

LO1 Understand the concepts of web application development
For this various technologies are used such as Ajax, ASP.NET, CSS, CGI, Java, etc. These have risk
factors similar to desktop applications. These have a lifecycle model such as Scrum, Feature driven
development, Extreme programming and Timebox development. Testing is performed on web
applications as well. Besides it requires some additional testing also such as Accessibility, Cross-
browser, responsiveness etc.
P1.1 - Critically evaluate the functions and advantages of web applications
Functions of Web Applications: The web apps are just like any regular computer program which is
able to perform some functions with the help of web browsers. The application can be simple or
complex. In a client server type model, clients are used referring to the programs which a person is
using in order to run the application. In this type of model, more than one computer shares their
data by entering information into the database. The client application is used for entering the
information while the server application is used for storing the information. With web applications,
the developer does not need to build a client for any type of operating system. So for accessing the
application, one only needs to have a internet connection. The client runs this using a web browser,
so the application should be platform compatible. Server side scripting and client side scripting is
commonly used in web applications in order to develop them. The client side focus mainly on
information presentation and server side deals with stuffs such as information retrieving and storing.
The web applications are as old as World Wide Web. As most of the web application involves client
server model as their architecture in which the clients have to enter the information and the server
retrieves and stores them. One such example is Internet mail.
Advantages of Web Applications:
 Cost effective type development
 Ubiquitous
 Easy to customize
 Device Compatible
 Easy to install and maintain
 Adaptable
 More Security
 Flexible
 Easy to develop
 More utilization
 Easy to grow
P1.2 – Critically compare different types of server-side and client-side
scripting languages.
Client-Side: On client-side, web browser runs. JavaScript is considered as the major scripting
language at client side for web. These are interpreted with the help of the browsers. The process
involves following procedure:
1. User first requests for a web page from the server.

2. Server then finds that page and upon searching it sends it back to user.
3. Page received from server is displayed on web browser.
So we can say that it is used to make changes to the web pages upon retrieval. It is used to make
these pages more user friendly. In short it is used for interaction and appearance. It highly depends
on user's computer. Their speed will depend on user's computer.
Server Side: The server contains web pages and other data. The server sends the requested pages to
clients upon requesting. The process at server side includes:
1. User first makes a request for web page from server.
2. Then page script gets interpreted by server.
3. Then the page is sent to user.
This allows users to have their individual accounts. It provides privacy levels, personalization etc. The
two important server side scripting languages are ASP.net and PHP. This script is then interpreted by
server. The user do not sees the server side scripting because they runs on server.
P1.3 – Examine web security and make recommendations for security
improvements.
The security of web is procedure of securing data which is stored online so as to prevent any
unauthorized modification and access. For this, some stringent policy rules are needed to be
accomplished. The main aim of implementing security to web applications is:
 To identify users that can access the data
 To identify vulnerabilities
 To identify risks
 To identify critical assets
 To identify access levels
In short, the main aim of implementing web security to web applications is
1. Confidentiality: It means that sensitive information should be kept secured and should not
be exposed ay any cost.
2. Availability: It means that the web application should be available for the access of the user
upon request.
3. Non Repudiation: It means one cannot deny his presence in the whole process.
4. Integrity: It means that the data in the web applications are consistent.

LO2 Be able to design web applications
P2.1 designs a web application to meet requirements given in the case
study.
For this website, user has provided some essential requirements. These are as under:
1. The implemented website should reflect the architecture in form of 3-tiers.
2. The website should have its front and backend to be connected.
3. The home page should include the logo of the company, name of the company, a dropdown
type menu bar, the objectives and goals of the company, footer and links to navigate to
other pages.
4. Some images that can give ideas about the company.
5. There should be minimum 4 pages for user interaction.
6. The font sizes and colours should be a standard one.
7. The database should be very appropriate

P2.2 Synthesise client-side and server-side functionality in a web application.
In the web applications, user requests to the server for the pages which he wants to access. The
server searches for the page and upon retrieval, it shows it on the display of the users. These are
executed on the browsers. It then allows users to interact with the website. In any web application,
two programs run simultaneously:
 The code at server side which is able to respond to requests by the users.
 The code at client side on the browser.
Server Side Functionality:
It includes languages like Ruby, Node.js, PHP, Java, JavaScript, python. C# etc. This is an infinite list
because any code which can run on computer and is able to respond to requests of the form HTTP
can run on the servers. It stores data which is persistent like pages, user profiles etc. The user cannot
see this. It is only able respond to HTTP requests.
Client Side Functionality:
It includes languages like CSS, JavaScript and HTML. These are parsed by user's browser. It is also
able to react with the user inputs. The user can see and edit them. The users cannot store any data
longer than page refresh. The files can be read directly from the server.

P2.3 Apply a database design for the given scenario.
1. Use Case: They are also called behavioural diagrams. They describe actions
which a system can perform in coordination with some external users. They
summarises relationships among use cases, systems and actors.
2. ERD: This stands for Entity Relationship Diagram. It is a flowchart that depicts
hoe entities relates with each other in the system. These are used for
designing of relational databases. They uses figures like diamonds, lines,
rectangles and ovals. Besides it is also used in troubleshooting of databases,
Business information systems, database design, education, research, etc
P2.4 Evaluate alternative designs and solutions to meet the given
requirement as explained in the case study.
The alternate solutions and designs that can be used to implement this system are:
1. WordPress:
It is the most popular world's CMS. It was started as open source tool for the use of website
owners. And now it is the most widely used tool for web development. It always remains the
first choice.
Advantages of WordPress:
 Easy: It is very easy to use as it does not requires any knowledge of HTML or PHP.
The plugins makes it easy to install them. The only thing which is needed is to
choose plugin and make it install.
 Community Support: It offers a huge community that supports the development by
providing them discussion boards.
 Plugins: In it, many plugins are available. The user can choose which plugin he wants
to use. A major part of plugins are kept for free use.
 Themes: It has free themes available for the usage. You can also purchase them if
any special theme is needed.
Disadvantages of WordPress:
 Modification may require the knowledge of languages like PHP.
 Modification of graphics requires some knowledge of HTML and CSS.
 Security Issues.
 No documentation is available.
2. Joomla:
It is a PHP open source which allows users to construct interactive and powerful websites. It
evolved in 2005. Since then, a total of four versions are released. It has multi-purpose usage.
With its wide variety of features, one can easily develop websites.

Advantages of Joomla:
 It is open source
 Multi language support
 Multi user authentication is available
 It has ACL system
Disadvatages of Joomla:
 Many of the extensions and plugins are not free.
 Only a limited access is available in order to customize the website.
 Less security
3. Drupal: It has comprehensive CMS. It has a narrow programming environment. It is
considered as complex open source system.
Advantages of Drupal:
 It has a large number of functionalities in it.
 It provides huge variety of types of contents.
 It offers advanced management for users.
 It has good graphic management and page management.
 It contains all the basic features needed.
Disadvantages of Drupal:
 It is not much user friendly.
 It has many performance issues.
 It has less efficiency and scalability as compared to others.