Lecture 3

The MVC Architecture

• The 3-Layer Architecture is a software design pattern that divides applications into three main categories or layers:
  • Presentation
  • Business Logic (or Application Layer)
  • Data Layer
• This architecture aims to separate the user interface, the business logic, and the data storage, which promotes a clean separation of concerns.

The MVC pattern is a specialized form of 3-layer architecture, making it highly relevant to modern web development practices

Components of MVC

Model–view–controller (MVC) - a software architectural pattern, that separates an application's data, user interface, and control flow into three components:

• Model:
  • Represents the data.
  • The model is often connected to a database and is responsible for retrieving and storing data.
• View:
  • Represents the user interface of an application,
  • is responsible for displaying data and getting user input.
  • HTML, CSS, and JavaScript.
• Controller:
  • Manages the flow of data between the model and the view,
  • is responsible for processing user input and directing the application’s behaviour.
  • includes code that implements business rules and other functionality.

Benefits of MVC

• Simplifies Complex Applications:

By separating the application into three components, developers can focus on one aspect without affecting others.

• Facilitates Parallel Development:

Different developers can work on the Model, View, and Controller simultaneously.

• Easy to Modify or Scale:

Changes to the business logic or user interface can be made with minimal impact on the other components.

• Supports Reusability:

Components can be reused across different parts of the application or in different applications.

Convention vs Configuration

Convention vs. Configuration is a design philosophy that:

• impacts how software frameworks are structured (i.e. where files are located)
• how they expect developers to interact with them
• It's a trade-off between the ease of following predefined paths and files (convention) or the flexibility to define everything explicitly (configuration).
• Important advice:
  • Web frameworks (CodeIgniter, Django, Ruby on Rails, Flask, Next,JS) come with a predefined folder structure
  • Learn what the structure is and where files go
  • This will improve your productivity!

Codeigniter