SwiftUI-Macros

A library of useful macros for SwiftUI.

Swift 5.9 or later is required to use this package.

Installation

Swift Package Manager

Add the dependency:

dependencies: [
    .package(url: "https://github.com/Wouter01/SwiftUI-Macros.git", from: "1.0.0")
]

Add the dependency to your target:

.target(
   name: "MyTarget",
   dependencies: [.product(name: "SwiftUIMacros", package: "SwiftUI-Macros")]
)

Environment

To allow easier creation of new environment keys, two macros are available:

EnvironmentKey

Apply this macro to a variable inside an EnvironmentValues extension to add it to the environment. The assigned value is the default value and is required, unless the type is Optional. The type can be inferred by its value, just like in normal Swift code.

import SwiftUIMacros

extension EnvironmentValues {
    @EnvironmentKey
    var alignment: Alignment = .center
}

// Expands to
extension EnvironmentValues {
    var alignment: Alignment {
      get {
        self[EnvironmentKey_alignment.self]
      }
      set {
        self[EnvironmentKey_alignment.self] = newValue
      }
    }
    
    private struct EnvironmentKey_alignment: EnvironmentKey {
       static let defaultValue: Alignment = .center
    }
}

EnvironmentValues

Apply this to an EnvironmentValues extension to add the EnviromentKey macro to each variable inside the extension.

import SwiftUIMacros

@EnvironmentValues
extension EnvironmentValues {
    var alignment: Alignment = .center
    
    var secondaryFont: Font?
    
    var gridLines = 0
}

// Expands to
extension EnvironmentValues {
    @EnvironmentKey
    var alignment: Alignment = .center
    
    @EnvironmentKey
    var secondaryFont: Font?
    
    @EnvironmentKey
    var gridLines = 0
}

Focus

To allow easier creation of new focusedValue keys, two macros are available:

FocusedValueKey

Apply this macro to a variable inside a FocusedValues extension to add it to the focused values.

import SwiftUIMacros

extension FocusedValues {
    @FocusedValueKey
    var enabled: Bool?
}

// Expands to
extension FocusedValues {
    @FocusedValueKey
    var enabled: Bool? {
        get {
            self [FocusedValueKey_enabled.self]
        }
        set {
            self [FocusedValueKey_enabled.self] = newValue
        }
    }
    
    private struct FocusedValueKey_enabled: FocusedValueKey {
        typealias Value = Bool
    }
}

FocusedValues

Apply this to an FocusedValues extension to add the FocusedValueKey macro to each variable inside the extension.

import SwiftUIMacros

@FocusedValues
extension FocusedValues {
    var showCompletions: Binding<Bool>?

    var value: Int?
}

// Expands to
extension FocusedValues {
    @FocusedValueKey
    var showCompletions: Binding<Bool>?

    @FocusedValueKey
    var value: Int?
}