SwiftUI MVVM Concept

It is not about how to create Lists and Charts and View design. It's about possibility how to organize View and Data layers within SwiftUI App. It's not about specifics how to implement Data layer. Apply your own stack to the concept.

Organizing View and Data layers within SwiftUI App

Concept based on protocols. It is not "typical" MVVM for SwiftUI as you might find on the web.

Aspirations

• Decouple View and Data layers and loosen dependencies between them
• Easily change a data source from Web to File etc.
• Easily change a data source format from JSON to XML, XML to CSV etc.
• Share the same data source between different View presentations(Grid, Chart other components)
• Maximize reusing code between different projects
• Easily split the development of View and Data layers between independent developers
• Testability

The principle of the concept is 1-2-3

1. Model

• Define Model

struct User: Model {    
    let id: Int    
    let name: String
    let age: Int
}

2. Store

• Define Store

It's store parameter for UniversalList View in the example

• Proxy is defining a communication layer. Proxies are used by Store to handle the loading and saving of Model data
• Reader is used to interpret data to be loaded into a Model instance

RemoteStore(
    proxy: File(
        reader: Json(),
        fileName: fileName
    )
)

3. View

• Define View

UniversalList(
    store: store,
    content: content,
    toolBar: toolBar
)

content parameter is a template for creating View depicting an entity toolBar set of predefined controls to manage View plus you can add your cystom set

SwiftUI template Development Architecture Designing with Protocols

App stores are assembled in AppViewModel In the code example. Two views (UniversalList, BarChart) implementing different presentation (Chart and List) share the same Store.

Writer is not implemented in the code example. It is placed on the diagram to show the comprehensiveness of the solution for any type of communication with remote sources

Class-Struct Diagramm

UI behavior

Click or tap the picture to watch the expected UI behavior of the example

• Shared source of data with different presentations
• Views control
• Dynamically added Views
• Master detail view
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Requirements

• Xcode Version 12.5+ Swift 5.3