103 lines
3.2 KiB
Swift
103 lines
3.2 KiB
Swift
//
|
|
// ViewBuilder.swift
|
|
// Meta
|
|
//
|
|
// Created by david-swift on 26.05.24.
|
|
//
|
|
|
|
import Foundation
|
|
|
|
/// The ``ViewBuilder`` is a result builder for views.
|
|
@resultBuilder
|
|
public enum ViewBuilder {
|
|
|
|
/// A component used in the ``ArrayBuilder``.
|
|
public enum Component {
|
|
|
|
/// A view as a component.
|
|
case element(_: AnyView)
|
|
/// An array of components as a component.
|
|
case components(_: [Self])
|
|
|
|
}
|
|
|
|
/// Build combined results from statement blocks.
|
|
/// - Parameter components: The components.
|
|
/// - Returns: The components in a component.
|
|
public static func buildBlock(_ elements: Component...) -> Component {
|
|
.components(elements)
|
|
}
|
|
|
|
/// Translate an element into a ``ViewBuilder.Component``.
|
|
/// - Parameter element: The element to translate.
|
|
/// - Returns: A component created from the element.
|
|
public static func buildExpression(_ element: AnyView) -> Component {
|
|
.element(element)
|
|
}
|
|
|
|
/// Translate an array of elements into a ``ViewBuilder.Component``.
|
|
/// - Parameter elements: The elements to translate.
|
|
/// - Returns: A component created from the element.
|
|
public static func buildExpression(_ elements: [AnyView]) -> Component {
|
|
var components: [Component] = []
|
|
for element in elements {
|
|
components.append(.element(element))
|
|
}
|
|
return .components(components)
|
|
}
|
|
|
|
/// Fetch a component.
|
|
/// - Parameter component: A component.
|
|
/// - Returns: The component.
|
|
public static func buildExpression(_ component: Component) -> Component {
|
|
component
|
|
}
|
|
|
|
// TODO: Add support for optionals, building either
|
|
/*
|
|
/// Enables support for `if` statements without an `else`.
|
|
/// - Parameter component: An optional component.
|
|
/// - Returns: A nonoptional component.
|
|
public static func buildOptional(_ component: Component?) -> Component {
|
|
.element(
|
|
Bin()
|
|
.child {
|
|
if let component {
|
|
buildFinalResult(component)
|
|
} else {
|
|
[]
|
|
}
|
|
}
|
|
.visible(component != nil)
|
|
)
|
|
}
|
|
|
|
/// Enables support for `if`-`else` and `switch` statements.
|
|
/// - Parameter component: A component.
|
|
/// - Returns: The component.
|
|
public static func buildEither(first component: Component) -> Component {
|
|
.element(ViewStack(id: true) { _ in buildFinalResult(component) })
|
|
}
|
|
|
|
/// Enables support for `if`-`else` and `switch` statements.
|
|
/// - Parameter component: A component.
|
|
/// - Returns: The component.
|
|
public static func buildEither(second component: Component) -> Component {
|
|
.element(ViewStack(id: false) { _ in buildFinalResult(component) })
|
|
}
|
|
*/
|
|
|
|
/// Convert a component to an array of elements.
|
|
/// - Parameter component: The component to convert.
|
|
/// - Returns: The generated array of elements.
|
|
public static func buildFinalResult(_ component: Component) -> [AnyView] {
|
|
switch component {
|
|
case let .element(element):
|
|
return [element]
|
|
case let .components(components):
|
|
return components.flatMap { buildFinalResult($0) }
|
|
}
|
|
}
|
|
|
|
}
|