How To Use MVVM in Flutter

A step-by-step guide for Flutter developers

Photo by Ray Hennessy on Unsplash

In this guide, we’ll briefly cover the following:

What is MVVM
Using MVVM in Flutter
Extending MVVM with Repository and Services

Note: The article assumes the reader knows about the Provider.

What is MVVM

Model-View-ViewModel (MVVM) is a software architectural pattern that supports the separation of the UI (which is View) from the development of the business logic or the backend logic (Model). The view model inside MVVM is the bridge responsible for data conversion in a way that behaves by the changes happening on the UI.

In addition, to know about the responsibilities of the three components, it’s also important to understand how they interact. At the highest level, the view “knows about” the view model, and the view model “knows about” the model, but the model is unaware of the view model, and the view model is unaware of the view.

There are several advantages of using MVVM:

• Separation of Concerns: It is a design principle for separating a computer program into distinct sections such that each section addresses a separate concern.
  A concern is anything that matters in providing a solution to a problem.
• Improved testability
• Defined project structure
• Parallel development of UI
• Abstract the View, thus reducing the quantity of business logic required in the code behind it

Some disadvantages of using MVVM:

• It has a slightly steep learning curve. How all the layers work together may take some time to understand.
• It adds a lot of extra classes, so it’s not ideal for low-complexity projects.

Since architectural or design patterns are platform-agnostic, they can be used with any framework, in our case, Flutter.