ViewModel

ViewModel is a SwiftUI framework that provides a starting point for your SwiftUI ViewModels. It makes it easier to structure your code and manage the state and behavior of your views.

Usage

To use SwiftUI ViewModel, create a subclass of ViewModel with Capabilities, Input, and Content types, and implement the content property with the content for the view. You can also provide additional properties and methods to manage the state and behavior of the view.

Here's an example of a simple view model:

class MyViewModel: ViewModel<Void, Void, MyContent> {
    @Published private var title: String = "Hello, World!"

    override var content: MyContent {
        MyContent(title: title)
    }
    
    init() {
        super.init(capabilities: (), input: ())
    }
}

In this example, MyViewModel has no capabilities or input, and its content is a MyContent object with a title property set to "Hello, World!".

To use this view model in a view, you can create an instance of MyViewModel and use its view method to return a view with the specified content and bindings:

struct MyView: View {
    @ObservedObject var viewModel = MyViewModel()

    var body: some View {
        viewModel.view { content in
            Text(content)
        }
    }
}

Bindings

If you need to have a Binding for a value, you can define it in the Input struct of your ViewModel. Here's an example of a ViewModel with Input:

class InputViewModel: ViewModel<Void, InputViewModel.Input, String> {
    struct Input {
        var textInput: String = ""
    }

    override var content: String {
        input.textInput
    }

    init() {
        super.init(capabilities: (), input: Input())
    }
}

To use this ViewModel in a view, you can use the binding method to get a Binding for the textInput property:

struct InputView: View {
    @ObservedObject var viewModel = InputViewModel()

    var body: some View {
        viewModel.view { content in
            TextField("Enter some text", text: viewModel.binding(\.textInput))
        }
    }
}