{"id":399147,"date":"2024-06-29T14:30:03","date_gmt":"2024-06-29T14:30:03","guid":{"rendered":"http:\/\/savepearlharbor.com\/?p=399147"},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-29T21:00:00","slug":"","status":"publish","type":"post","link":"https:\/\/savepearlharbor.com\/?p=399147","title":{"rendered":"SwiftUI and MVI<\/span>"},"content":{"rendered":"
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UIKit first appeared in iOS 2, and it is still here. Eventually we got to know it well and learned how to work with it. We have found many architectural approaches. MVVM, the most popular architecture in my opinion, has strengthened its position with the release of SwiftUI, while other architectures seemed to have some kind of problematic relationships with SwiftUI.<\/p>\n

But what if I told you that Clean Swift,\u00a0VIPER and other approaches can be adapted to SwiftUI. What if I told you that there are some modern architectures which might be as good as MVVM or even better.<\/p>\n

We will talk about MVI.<\/p>\n

I will break down what it is and use it as an example to show how you can adapt architectures to make them friendly with SwiftUI.<\/p>\n\n

The updated version of the MVI is here<\/a><\/p>\n\n

Bidirectional and Unidirectional architectures<\/h2>\n

All known architectures can be divided into two types:<\/p>\n

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  1. \n

    Bidirectional<\/p>\n<\/li>\n

  2. \n

    Unidirectional<\/p>\n<\/li>\n<\/ol>\n

    Bidirectional<\/strong>\u00a0architectures are divided into layers that transmit with each other. One layer can transmit and receive data from another layer.<\/p>\n

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    The main drawback of such architectures is the management of data flow. In large and complex screens it is difficult to navigate and almost impossible to keep in mind where the data came from, where it changes, and what the screen finally receives. These architectures are good for small to medium sized applications. They are generally simpler than Unidirectional architectures.<\/p>\n

    Unidirectional<\/strong>\u00a0architectures are divided into layers that transmit data to one type of layers and receive data from another type.<\/p>\n

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    Working with Unidirectional architecture may often cause the complaint, that some layers are excessive on simple screens, but you have to keep them. Another complaint is that with small changes you have to proxy data through all layers. All these disadvantages are compensated on large screens with complex logic. In such architectures duties are distributed better than in Bidirectional architectures. Working with code is simplified because it is easy to track where the data comes from, where it changes and where it goes away.<\/p>\n

    I was a bit unfair when I said at the beginning that there are architectures as good as MVVM or even better. They do exist, but work best for large projects. I\u2019m talking about MVI, Clean Swift and other Unidirectional approaches.<\/p>\n

    Let\u2019s take a closer look at one of these architectures.<\/p>\n

    MVI \u2014 brief history and principle of operation<\/h2>\n

    This pattern was first described by JavaScript developer Andre Staltz. The general principles can be found\u00a0here<\/u><\/a><\/p>\n

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