How can I create a View type that can accept a String or a View producing closure for it's init, similar to Button?

In SwiftUI, the Button struct declaration is this:

struct Button<Label> where Label : View

Two of Button’s init’s read as follows:

init<S>(_ title: S, action: @escaping () -> Void) where S : StringProtocol

and

init(action: @escaping () -> Void, label: () -> Label)

I’m trying to create a similar struct that can take either creates a Label : View from a String passed in the init, or passes a closure that produces a Label in the init.

Here’s what I’ve tried:

import SwiftUI

struct ContentView: View {
    var body: some View {
        HelpView("Learn more about locked and unlocked tracks",
                 url: "https://example.com/help")
    }
}

struct HelpView<Label>: View where Label : View {
    let url: String
    var label: () -> Label
    
    init<S>(_ text: S, url: String) where S : StringProtocol {
        self.url = url
        self.label = { Text(text) }
    }
    
    init(url: String, label: @escaping () -> Label) {
        self.url = url
        self.label = label
    }
    @State private var showWebView = false
    var body: some View {
        Button {
            showWebView = true
        } label: {
            label()
        }
        .sheet(isPresented: $showWebView) {
            //WebView(url: URL(string: url)!)
        }
    }
}

This doesn’t compile as I get

Generic parameter ‘Label’ could not be inferred

at the call site and

Cannot assign value of type ‘Text’ to type ‘Label’

in the StringProtocol init.

How can I make this work?

>Solution :

Just put init with string into separated extension with specifier (same as Apple does for Button)

Here is fixed code. Tested with Xcode 13.2 / iOS 15.2

struct HelpView<Label>: View where Label : View {
    let url: String
    var label: () -> Label

    init(url: String, label: @escaping () -> Label) {
        self.url = url
        self.label = label
    }

    @State private var showWebView = false
    var body: some View {
        Button {
            showWebView = true
        } label: {
            label()
        }
        .sheet(isPresented: $showWebView) {
            //WebView(url: URL(string: url)!)
        }
    }
}

extension HelpView where Label == Text {
    init<S>(_ text: S, url: String) where S : StringProtocol {
        self.url = url
        self.label = { Text(text) }
    }
}