MVVM.Demo.SwiftUI

MVVM - Model View ViewModel

MVVM Wiki: https://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93viewmodel

Overview

View

• UI elements
• Reacts to and interprets ViewModel through bindings

• Contains no business logic
• Stateless¹
• Holds a reference to the ViewModel

ViewModel

• Model interpretation

• Business logic

• Bindable properties
• Domain model dependencies injected as Protocols

• May contain child ViewModels

• Does not know about View

Model

• Anything that provides data or state to the ViewModel
• Does not know about the View or ViewModel

¹ No meaningful state is stored within the view. Anything needed by the model layer is immediately sent to the ViewModel from the View.

Coordinators

• Coordinators are aware of the user’s navigation context within the app
• Primarily responsible for Navigation and ViewModel injection
• Can contain child coordinators which are responsible for a narrowed context
• Only object to have a reference to the Dependency Injection container/resolver

Dependency Injection Container

• Manages references and lifetimes of registered objects

• Reduces the burden of dependency injection by defining all injections in one place

• Greatly improves the ability to unit test your code by registering contained objects as Protocols which can be substituted with mocks
• Makes sharing observable data throughout the app trivial while keeping each class/service focused and independent

Looking for older iOS Examples?

iOS 16

https://github.com/jasonjrr/MVVM.Demo.SwiftUI/releases/tag/3.0.0

iOS 14 & 15

https://github.com/jasonjrr/MVVM.Demo.SwiftUI/releases/tag/2.1.0

Version 2.1.0 was built on iOS 14 and solves the navigation problems most developers experiences with NavigationView.