Building Web Applications and Network Programming

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Building Web Applications and Network Programming
Building Web Applications and Network Programming

• Mr. Julius B. Suralta, MBM
• Engr. Luis Cadiz
• Mr. Jonie

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Topics

• Building Web Applications
• Protocols at the Application Layer
• Principles of Web Engineering
• Database-Driven Websites
• Remote Procedure Calls
• Light Weight Distributed Objects
• Role of Middleware
• Enterprise-Wide Web-based Applications
• Network Programming

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What is a Web Applications

• An application software created using the Web for
  deployment
• Many developers uses the WEB as a
  Platform-independent application environment
• A dynamic extension of a Web Server
• Examples Reservation System, Online Shopping or
  Auction Sites, Games, Multimedia applications,
  Calendars, Maps, chat applications, and a lot
  more.

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Web Applications background

• Over the past several years a number of different
  technologies have targeted application
  development on the Web. However, much of the work
  in this area has been proprietary and platform
  specific.
• Web applications typically have some form of
  programmatic control, either on the client, on
  the server or a combination of both. They may run
  within the browser, or within another host
  application.
• A Web application is typically downloaded on
  demand each time it is "executed", allowing a
  developer to update the application for all users
  when needed.
• Web applications are usually smaller than regular
  desktop applications, and can have rich graphical
  interactive interfaces.

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Web Applications Concerns

• A Web Application must address some of the
  following issues
• What functionality is needed for Web
  applications?
• What should a hosting environment provide?
• How much of a Web application should be
  declarative?
• How much in script?
• How are they related to Web documents, which are
  normally static?
• Is there a need for a standard set of user
  interface controls?
• Should these controls use the native platform
  look and feel?

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Web Applications Concerns

• What APIs are needed for Web applications (eg.
  retrieving and sending data over the network,
  parsing XML, client-side storage)?
• How should a Web application and its related
  resources (e.g. images, sounds) be packaged?
• What security issues need to be addressed?
• To what extent can application behavior be
  usefully abstracted from platform specific
  details of UI controls?
• How can the application integrate different
  modality interfaces (eg. voice, pen, keystrokes)?
  
• How to address richer models of interaction
  management that go beyond simple event handlers?

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Types of Web Applications

• Presentation-oriented. A presentation-oriented
  Web application generates dynamic Web pages
  containing various types of markup language
  (HTML, XML, and so on) in response to requests.
• Service-oriented. A service-oriented Web
  application implements the endpoint of a
  fine-grained Web service. Service-oriented Web
  applications are often invoked by
  presentation-oriented applications.

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Web Applications consist of

• Web components (html, cgi, others)
• Static Resource Files (images)
• Helper Classes
• Libraries.

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Web Applications

• Process for creating, deploying and executing a
  Web Applications
• Develop the Web component code (including
  possibly a deployment descriptor).
• Build the Web application components along with
  any static resources (for example, images) and
  helper classes referenced by the component.
• Install or deploy the application into a Web
  container.
• Access a URL that references the Web application.

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Web Applications

• Recommended Text Book
• Building Web Applications with UML
• 2nd Edition
• By Jim Conallen
• Web Application Evangelist
• of Rational Software Corp.

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Application Layer Protocols
Application Layer Protocols
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Application Layer Protocol

• The application layer protocols and standards are
  the ways in which different applications (like
  e-mail programs, web servers and browsers, etc.)
  talk to each other.    
• By protocols is meant the language used when the
  applications talk to each other through the
  network.

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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Application Layer Protocol
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Principles of Web Engineering
Principles of Web Engineering
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Concerns about Web Engineering

• Web applications are software artifacts, and as
  such can benefit by making use of established
  practices stemming from several related
  disciplines such as Software Engineering,
  Hypermedia, Information Systems and HCI, enabling
  creation, management and reuse of structures of
  the information space as well as enhancing the
  end user experience.
• It has its own characteristics which must be
  addressed, such as a varied user population, very
  short development turnaround times, diverse
  runtime environments, accessibility through
  multiple devices, etc.
• Web Engineering addresses these issues and
  focuses on systematic, disciplined and
  quantifiable approaches towards the
  cost-effective development and evolution of
  high-quality, ubiquitously usable Web-based
  systems and applications.

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Applying Software Engineering Principles to Web
Site Development Process

• Is called Web Site Waterfall Model
• It uses the iterative and incremental life cycle.
  In the iterative lifecycle, every iteration
  reproduces a lifecycle on a smaller scale.
• The objectives of iteration are established based
  on the evaluation of previous iterations.
• The iterative lifecycle revisits the various
  phases of the WebSite-Waterfall lifecycle several
  times.

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WebSite-Waterfall Model
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WebSite-Waterfall Model

• 1. Requirements Definition/Specification
• Requirements definition is the process by which
  the needs of the customer are translated into a
  clear, detailed specification of what the web
  site must do and achieve.
• The project specification must be in writing a
  verbal agreement is not acceptable. That way,
  when the customer changes their mind, you can
  renegotiate the work.
• The output from this phase is the specification
  document. The specification defines what the
  project does, not how the project does it

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WebSite-Waterfall Model

• 2. Requirements Analysis
• The development team analyzes the requirements
  and specifications document for completeness and
  feasibility.
• Once everyone agrees on the project
  specification, the next step is to analyze how to
  do it. The purpose of the analysis is to
  determine the scope of the effort. To help
  identify what is required for the project, it is
  necessary to answer to the following questions
• What is the software tools necessary?
• What developer skills are required for the
  project?
• A functional design document should be generated.
  This document consists of the information,
  figures and charts so that, when combined with
  the specification, someone new to the project can
  understand what the project does and how it does
  it.

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WebSite-Waterfall Model

• 3. Content Definition
• Developing the content of the web site consists
  of identifying the audience, defining the need of
  the audience, and developing a statement of
  purpose. This purpose should then guide the
  development of the content on the web site.

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WebSite-Waterfall Model

• 4. Layout and Navigation Design
• Laying out the navigation within the web site is
  key. The user should be directed logically
  through the web site so that they always know
  where they are going.
• The layout and navigation design process
  categorize the information and creates a
  flowchart, which outlines both the organization
  of the web site, and the links, which will exist
  within the web site. The structure should
  naturally follow the content.

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WebSite-Waterfall Model

• 5. Human Computer Interface Design
• Once it has been decided on the content, the
  organization of the web site has been outlined
  and navigation of the web site has been completed
  next the look of the web site should be
  addressed. The first step to designing the
  interface is to define what it is the user must
  accomplish. After defining the requirements, the
  next step is to determine the order a user would
  most likely use to accomplish the tasks. This
  requires understanding the target audience and
  how people want to do things. Once this is
  understood, the look and feel of the web site
  should be documented
• An initial paper design must be generated.
  Depending on the complexity of the design an
  evaluation should be made on whether it is
  necessary to develop a mock-up system that users
  may beta test.
• The documentation consists of the paper design of
  the major user interfaces and a flow diagram
  illustration how the interfaces interact with
  each other. If the user interface is simple
  enough, a text description of the interface is
  sufficient for documentation.

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WebSite-Waterfall Model

• 6. Multimedia/Graphics Design
• The multimedia/graphics design involves
  representing the accessories that will be added
  to the web site. When deciding which accessories
  to add, be aware of how much time its going to
  take to download. It must be determined if adding
  multimedia/graphics to the web site that the
  visual aspects of the web site will not distract
  users. The multimedia/graphics must be evaluated
  so that it is determined that the graphical
  content does not interfere with the readability
  of text.
• A document listing the multimedia/graphics that
  will be used on the web site, as well as where it
  will be used should be generated.

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WebSite-Waterfall Model

• 7. Implementation Unit Testing
• During this stage, the process of building the
  web according to its design is done. The detail
  of the operations is implemented. The integration
  of the new code with existing code, issued from
  previous iterations, is implemented gradually
  during the construction. Unit testing procedures
  are applied to the prototype. Unit testing
  involves verifying that each unit meets its
  specification.

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WebSite-Waterfall Model

• 8. Integration Testing
• The individual program units or programs are
  integrated and tested as a complete system to
  ensure that the web site requirements have been
  met. After testing, the web site is delivered to
  the customer.

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WebSite-Waterfall Model

• 9. Operations Maintenance
• Normally this is the longest life cycle phase.
  Before the software gets deployed to the world,
  it must be documented properly. The on-line help
  is created and checked against the distribution
  web site. Someone needs to use the system aided
  only with the on-line help and if a user can
  operate the system just from the on-line help,
  then it is ready for deployment.
• The web site is deployed and put into practical
  use. Maintenance involves correcting errors,
  which were not discovered in earlier stages of
  the life cycle improving the implementation of
  the web site and enhancing the services as new
  requirements are discovered.

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Database Driven Websites
Database Driven Websites
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Websites concern

• Websites represents the image of the company
• People visits websites looking for new
  information
• Most widely visited websites are those that
  provides real-time information such as CNN and
  others
• Maintenance to a hundreds of HTML files is a
  tedious job
• The content and layout of the website must change
  every now-and-then.
• Users and surfers visits most of the websites
  that are dynamics and only once for a static
  sites.

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Solutions

• By achieving complete separation between the
  site's design and the content we are looking to
  present, we can work with each without disturbing
  the other.
• Instead of writing an HTML file for every page of
  your site, we only need to write a page for each
  kind of information we want to be able to
  present.
• Instead of endlessly pasting new content into our
  tired page layouts, we create a simple content
  management system that allows the us writers to
  post new content themselves without a lick of
  HTML!

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Using RDBMS and Scripting Language

• MySQL
• MS SQL
• Oracle
• Sybase
• Informix
• Ingress
• dB
• Postgree
• Others

• PHP
• ASP
• Java Script
• VB Script
• Others

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Developer Must Know About

• HTML
• Java Script, Vb Script and Dynamic HTML
• Must master SQL
• Must have knowledge either ASP or PHP
• Must know how to use Apache or MS IIS

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Tips in Building Web Database Driven Applications
with PHP and MySQL

• Learn how to use array in PHP
• Including variables in string
• Use associative arrays to query results
• Beware of common PHP Bugs
• Using the Header() function for one-component
  querying
• Reload the problem and how to avoid it
• Locking for performance in web database
  applications
• Developing fast scripts with my_sql_unbuffered_que
  ry()

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Solutions
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Solutions