A lightweight SwiftUI validation library that provides real-time input validation with customizable rules and behaviors.
| Quick Start | Advanced Usage |
|---|---|
 |
 |
- Installation
- Quick Start
- Advanced Usage
- Debug Warnings (Misconfiguration)
- API Reference
- Requirements
- License
- Author
- Contributing
- File → Add Package Dependencies...
- Enter:
https://github.com/Ryosuke1025/ValidationLibrary - Select a version rule
- Add to your target
dependencies: [
.package(url: "https://github.com/Ryosuke1025/ValidationLibrary.git", from: "1.0.0")
]Minimal working example:
import SwiftUI
import ValidationLibrary
struct QuickStartView: View {
@State private var phoneNumber = ""
@State private var validationState = ValidationState()
var body: some View {
VStack {
TextField("Phone Number", text: $phoneNumber)
.keyboardType(.phonePad)
.validation(
text: $phoneNumber,
state: validationState,
rule: .numeric(minLength: 10, maxLength: 11)
)
if validationState.hasBeenValidated {
Text(validationState.isValid ? "Valid" : "Invalid")
.foregroundStyle(validationState.isValid ? .green : .red)
}
}
}
}Full example (matches the demo capture)
import SwiftUI
import ValidationLibrary
struct PhoneNumberView: View {
@FocusState private var isFocused: Bool
@State private var phoneNumber = ""
@State private var validationState = ValidationState()
var body: some View {
NavigationStack {
VStack(alignment: .leading, spacing: 8) {
TextField("Phone Number", text: $phoneNumber)
.keyboardType(.phonePad)
.focused($isFocused)
.validation(
text: $phoneNumber,
state: validationState,
rule: .numeric(minLength: 10, maxLength: 11)
)
.padding(16)
.background(in: .rect(cornerRadius: 16))
Text("10-11 digits, numbers only")
.foregroundStyle(.secondary)
.font(.caption)
if validationState.hasBeenValidated {
if validationState.isValid {
Text("Valid phone number")
.foregroundStyle(.green)
.font(.caption)
} else {
Text("Invalid phone number")
.foregroundStyle(.red)
.font(.caption)
}
}
}
.padding(16)
.frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .top)
.background(Color(.systemGroupedBackground))
.onTapGesture { isFocused = false }
.navigationTitle("Phone Number")
}
}
}Use ValidationContainer to validate multiple fields together.
Full example (matches the demo capture)
import SwiftUI
import ValidationLibrary
struct SignUpForm: View {
enum FocusField {
case email
case password
case confirmPassword
}
@FocusState private var focusedField: FocusField?
@State private var email = ""
@State private var password = ""
@State private var confirmPassword = ""
@State private var container = ValidationContainer()
var body: some View {
NavigationStack {
ScrollView {
VStack(spacing: 32) {
emailSection
passwordSection
confirmPasswordSection
statusSection
registerButton
}
.padding(16)
}
.frame(maxWidth: .infinity, maxHeight: .infinity)
.background(Color(.systemGroupedBackground))
.onTapGesture { focusedField = nil }
.navigationTitle("Sign Up")
}
}
private var emailSection: some View {
VStack(alignment: .leading, spacing: 8) {
TextField("Email", text: $email)
.textInputAutocapitalization(.never)
.keyboardType(.emailAddress)
.focused($focusedField, equals: .email)
.validation(
text: $email,
container: container,
id: "email",
rule: .email
)
.padding(16)
.background(in: .rect(cornerRadius: 16))
.overlay(alignment: .trailing) {
if let state = container.existingState(for: "email"),
state.hasBeenValidated {
if state.isValid {
Image(systemName: "checkmark.circle.fill")
.foregroundStyle(.green)
.padding(.trailing, 16)
} else {
Image(systemName: "xmark.circle.fill")
.foregroundStyle(.red)
.padding(.trailing, 16)
}
}
}
Text("Enter your email address")
.font(.caption)
.foregroundStyle(.secondary)
}
}
// Note: Using TextField instead of SecureField for demo recording purposes
private var passwordSection: some View {
VStack(alignment: .leading, spacing: 8) {
TextField("Password", text: $password)
.textInputAutocapitalization(.never)
.focused($focusedField, equals: .password)
.validation(
text: $password,
container: container,
id: "password",
rules: [.required, .password(minLength: 8)]
)
.padding(16)
.background(in: .rect(cornerRadius: 16))
.overlay(alignment: .trailing) {
if let state = container.existingState(for: "password"), state.hasBeenValidated {
if state.isValid {
Image(systemName: "checkmark.circle.fill")
.foregroundStyle(.green)
.padding(.trailing, 16)
} else {
Image(systemName: "xmark.circle.fill")
.foregroundStyle(.red)
.padding(.trailing, 16)
}
}
}
Text("8+ characters, letters and numbers")
.font(.caption)
.foregroundStyle(.secondary)
}
}
// Note: Using TextField instead of SecureField for demo recording purposes
private var confirmPasswordSection: some View {
VStack(alignment: .leading, spacing: 8) {
TextField("Confirm Password", text: $confirmPassword)
.textInputAutocapitalization(.never)
.focused($focusedField, equals: .confirmPassword)
.validation(
text: $confirmPassword,
container: container,
id: "confirmPassword",
rule: .custom { text in
text == password && !text.isEmpty
}
)
.onChange(of: password) {
if let state = container.existingState(for: "confirmPassword"),
state.hasBeenValidated {
container.validateAll()
}
}
.padding(16)
.background(in: .rect(cornerRadius: 16))
.overlay(alignment: .trailing) {
if let state = container.existingState(for: "confirmPassword"), state.hasBeenValidated {
if state.isValid {
Image(systemName: "checkmark.circle.fill")
.foregroundStyle(.green)
.padding(.trailing, 16)
} else {
Image(systemName: "xmark.circle.fill")
.foregroundStyle(.red)
.padding(.trailing, 16)
}
}
}
Text("Must match password")
.font(.caption)
.foregroundStyle(.secondary)
}
}
@ViewBuilder
private var statusSection: some View {
if container.hasBeenFullyValidated {
if container.isFullyValid {
Text("Valid Input")
.foregroundStyle(.green)
} else {
Text("Invalid Input")
.foregroundStyle(.red)
}
}
}
private var registerButton: some View {
Button("Register") {
focusedField = nil
container.validateAll()
}
.buttonStyle(.borderedProminent)
}
}In DEBUG builds, the library reports developer-facing issues to help you catch misconfigurations early:
| Type | Examples |
|---|---|
 Runtime warning |
|
 Assertion failure |
|
func validation(
text: Binding<String>,
state: ValidationState,
rules: [ValidationRule], // or rule: ValidationRule
timing: ValidationTiming = .realtime(),
behavior: ValidationInitialBehavior = .afterFirstEdit
) -> some Viewfunc validation(
text: Binding<String>,
container: ValidationContainer,
id: String,
rules: [ValidationRule], // or rule: ValidationRule
timing: ValidationTiming = .realtime(),
behavior: ValidationInitialBehavior = .afterFirstEdit
) -> some View| Member | Type | Notes |
|---|---|---|
isValid |
Bool |
Current validity. |
hasBeenValidated |
Bool |
Whether validation has run at least once. |
hasBeenEdited |
Bool |
Whether the user has edited the field. |
hasBeenBlurred |
Bool |
Whether the field has lost focus at least once. |
invalidReason |
InvalidReason? |
Failure reason (nil when valid / not validated). |
reset() |
() |
Reset state flags and validity. |
| Member | Type | Notes |
|---|---|---|
isFullyValid |
Bool |
False when empty; otherwise true only when all fields are valid. |
hasBeenFullyValidated |
Bool |
False when empty; otherwise true only when all states have been validated. |
state(for:) |
ValidationState |
Get or create a state for an id. |
existingState(for:) |
ValidationState? |
Get an existing state (nil if not created yet). |
resetAll() |
() |
Reset all states. |
validateAll() |
() |
Validate all registered states. |
| Case | Notes |
|---|---|
.required(minLength:maxLength:) |
Optional length constraints. |
.email(minLength:maxLength:) |
Optional length constraints. |
.password(minLength:maxLength:) |
Must contain at least one letter and one digit. Optional length constraints. |
.numeric(minLength:maxLength:) |
Optional length constraints. |
.regex(String) |
Pattern string is used for validation. |
.custom(messageKey:validator:) |
messageKey is optional and can help map UI messages when multiple customs exist. |
| Case | Meaning |
|---|---|
.empty |
The input is empty (or whitespace-only). |
.emailFormat |
The input is not a valid email format. |
.passwordFormat |
The input is not a valid password format. |
.numericFormat |
The input contains non-numeric characters. |
.regexFormat(id:regex:) |
The input does not match a regex. (id is currently nil from the library.) |
.tooShort(min:actual:) |
The input is shorter than the minimum length. |
.tooLong(max:actual:) |
The input is longer than the maximum length. |
.custom(id:) |
Custom validation failed (id can be used for UI mapping). |
| Case | Meaning |
|---|---|
.realtime(debounce:) |
Validate while typing (optional debounce). |
.onFocusLoss |
Validate when focus leaves the field. |
| Case | Meaning |
|---|---|
.afterFirstEdit |
Start validating after the first edit. |
.onStart |
Validate immediately on appearance. |
.afterFirstBlur |
Start validating after the first blur. |
- iOS 17.0+ / macOS 14.0+ / watchOS 10.0+ / tvOS 17.0+
- Swift 6.0+
- Xcode 16.0+
ValidationLibrary is available under the MIT license. See the LICENSE file for more info.
Ryosuke Suzaki (@Ryosuke1025)
Contributions are welcome! Please feel free to submit a Pull Request.