Validate

A property wrapper that can validate the property it wraps.

When the wrapped value changes @Validate will run the provided validations against the value.

Once validated, the isValid and errors properties can provide validation results.

The Validate framwork contains a number of built in validations such as presence, count and format. All which a various array of types.

Requirements

• iOS 15.0+
• macOS 12.0+

Installation

Swift Package Manager

dependencies: [
    .package(url: "https://github.com/reddavis/Validate", from: "2.0.0")
]

Documentation

API Reference

Usage

import SwiftUI
import Validate


struct ContentView: View {
    @Validate(.presence()) var name: String = ""
    
    var body: some View {
        VStack(spacing: 60) {
            VStack {
                TextField("Name", text: self.$name.binding)
                    .textFieldStyle(.roundedBorder)
                    .padding()
                
                VStack {
                    ForEach(self.$name.errors.localizedDescriptions, id: \.self) { message in
                        Text(message)
                            .foregroundColor(.red)
                            .font(.footnote)
                    }
                }
            }
            
            Button("Save") {
                print(self.name)
            }
            .buttonStyle(.bordered)
        }
    }
}

Built in validations

Validate includes several validations:

• Count
• Presence
• Format

Building validations

You're not just limited to using the built in validations but can build your own by using the Validation builder.

This is how the built in presence validation is built:

public extension Validation {
    /// Validate an optional value is present.
    ///
    /// If the value is nil, it is considered invalid.
    /// - Parameters:
    ///   - message: A custom error message.
    /// - Returns: A Validation instance.
    static func presence<T>(
        message: String? = nil
    ) -> Validation<Optional<T>> {
        .init { value in
            if value == nil {
                throw ValidationError.build(message: message)
            }
        }
    }
}

Other libraries

Check out some of my other libraries:

• Papyrus - Papyrus aims to hit the sweet spot between saving raw API responses to the file system and a fully fledged database like Realm.
• RedUx - A super simple Swift implementation of the redux pattern making use of Swift 5.5's new async await API's.
• Kyu - A persistent queue system in Swift.
• FloatingLabelTextFieldStyle - A floating label style for SwiftUI's TextField.
• Panel - A panel component similar to the iOS Airpod battery panel.