App Architecture — 🏗️ Unveiling MVVM (Model-View-ViewModel) 🏗️

In this article, we embark on a journey to explore the innovative world of Model-View-ViewModel (MVVM) architecture — a cutting-edge design pattern that revolutionises how we create robust and user-friendly software.🚀

Source: Github

Introduction 🎉

In the realm of Software development, crafting applications that are not only powerful but also maintainable and scalable is crucial. To accomplish this, developers rely on architectural patterns that organize code, improve maintainability, and promote reusability. Among these powerful patterns stands the Model-View-ViewModel (MVVM) architecture. MVVM has gained immense popularity and has proven to be highly effective in a wide range of application types.

What is MVVM Architecture?

MVVM is an architectural design pattern that divides an application into three essential components: Model, View, and ViewModel. Each component has a specific role, leading to a cleaner and more manageable application structure.

Concept behind MVVM

At the heart of MVVM lies the concept of separation of concerns, where each component takes on distinct responsibilities and operates independently.

• Model: The Model represents the application’s data and business logic, similar to the MVC pattern. It manages data manipulation, validation, and interactions with data sources. However, in MVVM, the Model does not directly communicate with the View; it remains agnostic of the user interface, which enhances flexibility.
• View: The View is responsible for displaying data to the user and capturing user input. Unlike in MVC, the View in MVVM has a passive role and does not contain any business logic. Instead, it binds to the ViewModel to receive data updates and user interactions.
• ViewModel: The ViewModel acts as an intermediary between the Model and the View. It exposes data and commands from the Model to the View through data binding. The ViewModel also handles user interactions from the View and updates the Model accordingly. In essence, it abstracts the View’s state and behaviour, making it easier to manage and test.

How does MVVM work?

Let’s illustrate MVVM using a simple analogy of sending a message, considering both the user’s perspective and the technical perspective.

example showing interaction between the components

• From a user perspective, imagine sending a message to a friend. You compose the message, and it’s ready to be delivered.
• In MVVM, when the user interacts with the View (composing the message), the ViewModel comes into play as the coordinator. The ViewModel receives the message and ensures it is appropriately formatted and ready to be sent.
• The ViewModel then communicates with the Model (sending the message) to handle the actual sending process.
• After successfully sending the message, the Model communicates back to the ViewModel, confirming the delivery.
• The ViewModel, in turn, updates the View, displaying a confirmation to the user that the message has been sent.

Project Folder Structure using MVVM

Just as we structured a project using MVC, let’s take a glimpse at how we can arrange our files based on the MVVM architecture for a web-based application.

MVVM Project Folder Structure

project/
|-- src/
|   |-- models/              # Contains data models or entities
|   |-- view/                # Contains View-related files
|   |   |-- components/      # Reusable UI components
|   |   |-- screens/         # Individual screens or pages
|   |-- viewmodel/           # Contains ViewModel classes
|   |-- services/            # Services for data access or API calls
|   |-- utils/               # Utility functions and helpers
|-- tests/                   # Unit tests, integration tests, etc.
|-- assets/                  # Static assets like images, fonts, etc.
|-- app.js                   # Main application entry point
|-- index.html               # HTML template for the app
|-- styles.css               # Global styles or CSS files
|-- package.json             # Project configuration and dependencies
|-- webpack.config.js        # Webpack configuration (if used)
|-- README.md                # Project documentation

Non-MVVM Project Folder Structure

project/
|-- src/
|   |-- components/          # Reusable UI components
|   |-- screens/             # Individual screens or pages
|   |-- services/            # Services for data access or API calls
|   |-- utils/               # Utility functions and helpers
|-- tests/                   # Unit tests, integration tests, etc.
|-- assets/                  # Static assets like images, fonts, etc.
|-- app.js                   # Main application entry point
|-- index.html               # HTML template for the app
|-- styles.css               # Global styles or CSS files
|-- package.json             # Project configuration and dependencies
|-- webpack.config.js        # Webpack configuration (if used)
|-- README.md                # Project documentation

Please note that this folder structure may vary depending on the project’s specifics. The example aims to provide a fundamental understanding of the organisation.

The Benefits of MVVM Architecture:

• Separation of Concerns: MVVM enforces a clear separation of concerns, leading to better code organisation and maintainability.
• Testability: The decoupled components in MVVM make it easier to test each part in isolation, improving the overall test coverage and reliability.
• Reusability: The segregation of responsibilities allows for greater reusability of ViewModels and Views in different sections of the application.
• User Experience: MVVM supports smoother user experiences as Views can update dynamically and asynchronously, providing real-time data to the user.

Conclusion

MVVM architecture is a forward-thinking design pattern that empowers developers to create sophisticated and user-friendly applications. By breaking down the application into Model, View, and ViewModel, developers can achieve an organised, testable, and flexible codebase. MVVM has proven its effectiveness and remains a top choice for modern software development projects.

If you’re on a quest to build a powerful application, adopting the MVVM architecture can elevate your development process and lead to a delightful user experience. 🚀

Until Next Time….. 👋👋

Learn about MVC Architecture

Application Architecture — Understanding MVC (Model-View-Controller)