SwiftUI Helpers

IfViews.swift

import Combine
import SwiftUI

struct IfNotNil<Value, Content>: View where Content: View {
    
    private let value: Value?
    private let content: (Value) -> Content

    init(_ value: Value?,
         @ViewBuilder show content: @escaping (Value) -> Content) {
        self.value = value
        self.content = content
    }

    var body: some View {
        value.map(content)
    }
}

struct IfNil<Value, Content: View>: View {
    
    private let bool: Bool?
    private let content: Content

    init(_ value: Value?,
         @ViewBuilder show content: @escaping () -> Content) {
        if value == nil {
            self.bool = false
        } else {
            self.bool = nil
        }
        self.content = content()
    }

    var body: some View {
        bool.map({ _ in content})
    }
}

struct If<Value, Content1, Content2>: View where Content1: View, Content2: View {
    
    private let value: Value?
    private let content1: (Value) -> Content1
    private let content2: Content2

    init(notNil value: Value?,
         @ViewBuilder show content1: @escaping (Value) -> Content1,
         @ViewBuilder elseShow content2: @escaping () -> Content2) {
        self.value = value
        self.content1 = content1
        self.content2 = content2()
    }

    var body: some View {
        ZStack {
            IfNil(value) {
                self.content2
            }
            IfNotNil(value) {
                self.content1($0)
            }
        }
    }
}