Unit 1 IS 413

Question 1

What’s MVC?

MVC?

Answer 1

Models: Data
Views: Front End:
Controllers: Business Logic

(Ford Motor assembly line example)

1. Model
   Purpose: Manages the data, business logic, and rules of the application.
   Responsibilities:
   Interacts with the database or other data sources.
   Processes and handles data (e.g., applying calculations, validations, or transformations).
   Notifies views or controllers about data updates.
   Example:
   In a to-do app, the Task model would handle storing, retrieving, and updating tasks in the database.
2. View
   Purpose: Handles the user interface and presentation layer.
   Responsibilities:
   Displays data to the user (pulled from the model).
   Collects user input and passes it to the controller.
   Updates the UI in response to changes in the model.
   Example:
   A web page showing a list of tasks and a form for adding a new task.
   In a web app, views are often HTML, CSS, and front-end JavaScript templates.
3. Controller
   Purpose: Acts as a mediator between the model and the view.
   Responsibilities:
   Handles user input (e.g., button clicks, form submissions).
   Updates the model based on user actions or events.
   Determines which view to render in response to a user action or a state change in the model.
   Example:
   When a user clicks “Add Task,” the controller receives the request, sends data to the model to save the task, and then updates the view to reflect the new task.
   How MVC Works Together
   User interaction: A user interacts with the interface (view), such as clicking a button.
   Controller action: The controller handles the input, processes it, and updates the model.
   Model update: The model performs the necessary operations, such as saving data to the database.
   View update: The view retrieves updated data from the model and displays it to the user.
   MVC Workflow Example
   Imagine an online store:

A user adds an item to their cart (via the View).
The Controller processes this action, validating the input and calling the Model.
The Model updates the cart’s data in the database.
The updated cart data is fetched and displayed by the View.
Advantages of MVC
Separation of Concerns: Each component has a distinct role, making the application easier to develop, test, and maintain.
Scalability: Modular structure allows for independent updates or expansions.
Code Reusability: Models and controllers can often be reused across multiple views.
Disadvantages of MVC
Complexity: For small applications, implementing MVC might feel unnecessarily complicated.
Tight Coupling: Changes in one component may sometimes require updates in others.
Steeper Learning Curve: Understanding and properly implementing MVC can be challenging for beginners.
MVC in Practice
Web Frameworks:
Ruby on Rails: Follows MVC strictly.
Django (Python): Similar to MVC, though it uses “Template” instead of “View.”
ASP.NET MVC: Microsoft’s implementation of MVC for web apps.
Express.js: Often used with MVC for Node.js applications.
Front-End Frameworks:
React, Angular, and Vue.js implement variations of the MVC concept for the client-side.