MVVM: A Tutorial and Practical Example in Swift

MVVM rather than MVC? What are the differences, and why should we care? Here is an explanation, with a few diagrams (and an example) to help!

A representation of the MVVM model

MVVM was proposed by John Gossman in 2005. Interestingly the view should consist only of visual elements — and not make network calls or similar.

All architectures have advantages and disadvantages, but MVVM has become increasingly popular in implementations.

Some want a video, and here is one (it covers a slightly different example than the one in this article so they go well together!).

Prerequisites:

• Some understanding of OO terminology and practices
• Swift’s Result type is used later in the post

Terminology

Binding: The mapping of one thing to another.

View Controller: Sits between the view and the model, tying them together (usually using the…