SwiftUIFormValidator

The world's easiest, most clean SwiftUI form validation.

SwiftUIFormValidator

A declarative SwiftUI form validation. Clean, simple, and customizable.

Discuss it on Product Hunt 🦄

Form Screenshot

Table of contents

• Usage
  • Basic Setup
  • Validation Types
  • Inline Validation
  • Manual Validation
  • React to Validation Change
• Installation
  • CocoaPods
  • Swift Package Manager
  • Accio
  • Carthage
• Validators
• Custom Validators
• Validation Messages
• Contribution
• Changelog
• License

⚡ Usage

Basic Setup

  // 1 
import FormValidator

// 2
class FormInfo: ObservableObject {
    @Published var firstName: String = ""
    // 3
    lazy var form = {
        FormValidation(validationType: .immediate)
    }()
    // 4
    lazy var firstNameValidation: ValidationContainer = {
        $firstName.nonEmptyValidator(form: form, errorMessage: "First name is not valid")
    }()
}

struct ContentView: View {
    // 5
    @ObservedObject var formInfo = FormInfo()

    var body: some View {
        TextField("First Name", text: $formInfo.firstName)
                .validation(formInfo.firstNameValidation) // 6
    }
}

1. Import FormValidator.
2. Declare an ObservableObject for the form with any name, for example, FormInfo, LoginInfo, or any name.
3. Declare FormValidation object and choose a validation type.
4. Declare a ValidationContainer for the field you need to validate.
5. In your view, declare the FormValidation object.
6. Declare validation(formInfo.firstNameValidation) with the validation of the field.

Congratulation!! your field is now validated for you!

Inline Validation

For fast validation, you can use InlineValidator and provide your validation logic in line:

 lazy var lastNamesValidation: ValidationContainer = {
    $lastNames.inlineValidator(form: form) { value in
        // Put validation logic here
        !value.isEmpty
    }
}()

Validation Types

You can choose between 2 different validation types: FormValidation(validationType: .immediate) and FormValidation(validationType: .deffered)

1. immediate: the validation is triggered every time the field is changed. An error message will be shown in case the value is invalid.
2. deferred: in this case, the validation will be triggered manually only using FormValidation.triggerValidation() The error messages will be displayed only after triggering the validation manually.

Manual Validation

You can trigger the form validation any time by calling FormValidation.triggerValidation(). After the validation, each field in the form will display error message if it's invalid.

React to Validation Change

You can react to validation change using FormValidation.$allValid and FormValidation.$validationMessages

VStack {
} // parent view of the form
        .onReceive(formInfo.form.$allValid) { isValid in
            self.isSaveDisabled = !isValid
        }
        .onReceive(formInfo.form.$validationMessages) { messages in
            print(messages)
        }

🎉 Installation

CocoaPods

Use the following entry in your Podfile:

pod 'SwiftUIFormValidator'

Then run pod install.

Swift Package Manager

Add the following as a dependency to your Package.swift:

.package(url: "https://github.com/ShabanKamell/SwiftUIFormValidator.git")

and then specify "SwiftUIFormValidator" as a dependency of the Target in which you wish to use SwiftUIFormValidator. Here's an example PackageDescription:

// swift-tools-version:5.1

import PackageDescription

let package = Package(
        name: "MyPackage",
        products: [
            .library(
                    name: "MyPackage",
                    targets: ["MyPackage"]),
        ],
        dependencies: [
            .package(url: "https://github.com/ShabanKamell/SwiftUIFormValidator")
        ],
        targets: [
            .target(
                    name: "MyPackage",
                    dependencies: ["SwiftUIFormValidator"])
        ]
)

Accio

Accio is a dependency manager based on SwiftPM which can build frameworks for iOS/macOS/tvOS/watchOS. Therefore the integration steps of SwiftUIFormValidator are exactly the same as described above. Once your Package.swift file is configured, run accio update instead of swift package update.

Don't forget to add import FormValidator to use the framework.

Carthage

Carthage users can point to this repository and use generated SwiftUIFormValidator framework.

Make the following entry in your Cartfile:

github "ShabanKamell/SwiftUIFormValidator"

Then run carthage update.

If this is your first time using Carthage in the project, you'll need to go through some additional steps as explained over at Carthage.

Validators

Custom Validators

In easy steps, you can add a custom validator:

// 1
public class NonEmptyValidator: StringValidator {
    public var publisher: ValidationPublisher!
    public var subject: ValidationSubject = .init()
    public var onChanged: ((Validation) -> Void)? = nil

    public var errorMessage: StringProducerClosure = {
        ""
    }
    public var value: String = ""

    public func validate() -> Validation {
        if value.trimmingCharacters(in: .whitespaces).isEmpty {
            return .failure(message: errorMessage())
        }
        return .success
    }
}

// 2
extension Published.Publisher where Value == String {
    func nonEmptyValidator(
            form: FormValidation,
            errorMessage: @autoclosure @escaping StringProducerClosure = ""
    ) -> ValidationContainer {
        let validator = NonEmptyValidator()
        let message = errorMessage()
        return ValidationPublishers.create(
                form: form,
                validator: validator,
                for: self.eraseToAnyPublisher(),
                errorMessage: !message.isEmpty ? message : form.messages.required)
    }
}

1. Implement FormValidator protocol.
2. Add the validator logic in an extension to Published.Publisher.

Note

NonEmptyValidator is a built-in validator in the library.

Validation Messages

You can provide a validation message for every field by providing errorMessage

$firstName.nonEmptyValidator(form: form, errorMessage: "First name is not valid")

If you don't provide a message, a default one will be used for built-in providers. All default messages are located in DefaultValidationMessages class.

$firstName.nonEmptyValidator(form: form) // will use the default message

In this example, DefaultValidationMessages.required will be used.

Overriding Default Validation Messages

You can override the default validation messages by inheriting from DefaultValidationMessages

class ValidationMessages: DefaultValidationMessages {
    public override var required: String {
        "Required field"
    }
    // Override any message ...
}

Or if you need to override all the messages, you can implement ValidationMessagesProtocol.

And provide the messages to FormValidation

FormValidation(validationType: .immediate, messages: ValidationMessages())

Credit

Validation with SwiftUI & Combine

👏 Contribution

All Pull Requests (PRs) are welcome. Help us make this library better.

Changelog

Look at Changelog for release notes.

License

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.