Web Application Development

• Introduction to Web Applications

Course Objectives

• Define web applications and their characteristics compared to desktop applications.
• Explain the implications of multiple users on non-functional requirements.
• Define non-functional requirements for software.
• Define Architectural Design as a solution to non-functional issues.
• Define model-driven programming, which allows prioritizing architectural design over analysis.
• Identify middleware for connecting different software components within the architecture.

Core Focus

• The main focus of the material is on how to develop applications that are intended to be deployed on multiple devices (server or client) connected to each other via a network (LAN or WAN). The basis of engineering is the architecture. The difference between the engineer and the rest of the people working on the application lies here. There is a basic engineering triangle that must be balanced according to the nature of the project being developed, and it relates to non-functional properties: time, cost, and quality.

Key Concepts

• Each element has a concept called the acceptance threshold, which is the maximum limit each factor can tolerate, beyond which the plan cannot be accepted.
• When the architecture is completed by the engineer, they have completed the critical part of the quality factor, and the time and cost factors remain, taking into account that achieving one factor comes at the expense of the other.
• Continuous improvement on one factor comes at the expense of decreasing the quality of achieving other factors. Dealing with this triangle is what distinguishes one engineer from another, and makes an engineer get paid more than another engineer.

Project Success Factors

• In any project, the engineer must know when the project will end, what quality is required to complete this project, and also must have experience in knowing the costs associated with completing the project.
• Specifications determine the quality of the program, and the intended quality is the program's response when a specific number of users are present.

Engineer's Role in Optimization

• The engineer must be inspiring in the optimization process, which means that we are faced with several options and that we rely on the optimal solution, which is the solution that includes the best combination of engineering triangle elements so that we do not deviate from the main goal of the plan. This requires that the engineer understands the business in which he works, in addition to having foresight and continuous follow-up.
• The project has a general structure to succeed, and its success is not related to a specific developer who is good at a suitable programming language to complete the project. The project has several options from developers who are good at dealing with a specific technology, so the project depends on the engineer who achieves a correct structure for the project. Herein lies the importance of the engineer for the project, in addition to his understanding of the requirements of the business that we work in its framework, which makes this engineer indispensable in the company.

Focus Areas in Software Engineering

• The first axis includes quality: here we talk about architecture, design, analysis, modeling (UML), and testing.
• The second axis includes time and cost: here we are in the project management phase.
• The process of designing program structure is linked to the structure of the computer, so we studied courses such as computer structure in previous years.

Important Terms

• Analysis: Describing the system from the user's point of view, without going into details of what programming languages are used or the data structure, etc.

Design

• The process of mapping the analysis onto the structure until we know the correct sequence of implementation steps, and in this course we will learn about the 7 layers of the structure.
• Example: The multiple sorting algorithms that we studied in previous courses each differ from the other in their structure, such as the difference in the data structure used and the difference in the algorithm's handling of the data size, and so we study the structure to choose the best solution. The most important thing in the design phase is the use case diagram, as the designer is concerned with reaching the use case diagram, and the rest of the diagrams are explanatory.

Explore web applications, their characteristics, and differences from desktop applications. Understand the implications of multiple users on non-functional requirements. Learn about architectural design and middleware for connecting software components.