Simplifies text field validation by providing reusable validators for form inputs, supporting severity levels for validation messages and customizable user interaction behavior.
TextField validation is a pain, hopefully this is a bit easier
Full documentation & pattern guides → — basic screens, ViewModel, MVI/UDF, and Circuit wiring, with every example compiled in CI against the current API.
@Composable
fun BasicSignUpScreen(onSubmit: (email: String, password: String) -> Unit) {
// No state holder: the validators live in the composable, remembered across
// recompositions. Each one owns its TextFieldValue draft + validation state.
val email = rememberTextFieldValueValidator(rules = listOf(Required, Email))
val password = rememberTextFieldValueValidator(rules = listOf(Required, MinLength(8)))
Column {
with(email) {
OutlinedTextField(
value = value,
onValueChange = ::onValueChange,
label = { Text("Email") },
isError = isError(),
supportingText = supportingText(),
singleLine = true,
modifier = Modifier
.fillMaxWidth()
// Show errors when focus leaves the field; shake on invalid submit.
.validationConfig(validateOnFocusLost = true, shakeOnInvalid = true),
)
}
with(password) {
OutlinedTextField(
value = value,
onValueChange = ::onValueChange,
label = { Text("Password") },
isError = isError(),
supportingText = supportingText(),
singleLine = true,
modifier = Modifier
.fillMaxWidth()
.validationConfig(validateOnFocusLost = true, shakeOnInvalid = true),
)
}
Button(
onClick = {
// Form-level validate(): surfaces errors on every field, true when all pass.
if (listOf(email, password).validate()) {
onSubmit(email.value.text, password.value.text)
}
},
modifier = Modifier.fillMaxWidth(),
) { Text("Create account") }
}
}Prefer the state holder to own the form? Yakcov also works headlessly — a
ViewModel/presenter owns a FieldValidator, or a pure MVI reducer folds rules with
toFieldState. See the
ViewModel and
MVI/UDF guides.
Published to Maven Central for all targets (Android, JVM, JS, Wasm, iOS) — depend on the common artifact and each of your targets resolves its own:
commonMain {
dependencies {
implementation("com.chrisjenx.yakcov:library:${version}")
}
}For a single target, depend on it directly — Android, for example:
dependencies {
implementation("com.chrisjenx.yakcov:library-android:${version}")
}The PhoneFormat rule validates phone-number format with no extra dependencies. The
region-aware Phone rule needs the (compileOnly) libphonenumber dependency added to your app —
see phone validation.
JDK 17+ required; check your system with KDoctor. Run tests with
./gradlew :library:allTests — the JS/WasmJS tests need Chrome installed.
TextField validation is a pain, hopefully this is a bit easier
Full documentation & pattern guides → — basic screens, ViewModel, MVI/UDF, and Circuit wiring, with every example compiled in CI against the current API.
@Composable
fun BasicSignUpScreen(onSubmit: (email: String, password: String) -> Unit) {
// No state holder: the validators live in the composable, remembered across
// recompositions. Each one owns its TextFieldValue draft + validation state.
val email = rememberTextFieldValueValidator(rules = listOf(Required, Email))
val password = rememberTextFieldValueValidator(rules = listOf(Required, MinLength(8)))
Column {
with(email) {
OutlinedTextField(
value = value,
onValueChange = ::onValueChange,
label = { Text("Email") },
isError = isError(),
supportingText = supportingText(),
singleLine = true,
modifier = Modifier
.fillMaxWidth()
// Show errors when focus leaves the field; shake on invalid submit.
.validationConfig(validateOnFocusLost = true, shakeOnInvalid = true),
)
}
with(password) {
OutlinedTextField(
value = value,
onValueChange = ::onValueChange,
label = { Text("Password") },
isError = isError(),
supportingText = supportingText(),
singleLine = true,
modifier = Modifier
.fillMaxWidth()
.validationConfig(validateOnFocusLost = true, shakeOnInvalid = true),
)
}
Button(
onClick = {
// Form-level validate(): surfaces errors on every field, true when all pass.
if (listOf(email, password).validate()) {
onSubmit(email.value.text, password.value.text)
}
},
modifier = Modifier.fillMaxWidth(),
) { Text("Create account") }
}
}Prefer the state holder to own the form? Yakcov also works headlessly — a
ViewModel/presenter owns a FieldValidator, or a pure MVI reducer folds rules with
toFieldState. See the
ViewModel and
MVI/UDF guides.
Published to Maven Central for all targets (Android, JVM, JS, Wasm, iOS) — depend on the common artifact and each of your targets resolves its own:
commonMain {
dependencies {
implementation("com.chrisjenx.yakcov:library:${version}")
}
}For a single target, depend on it directly — Android, for example:
dependencies {
implementation("com.chrisjenx.yakcov:library-android:${version}")
}The PhoneFormat rule validates phone-number format with no extra dependencies. The
region-aware Phone rule needs the (compileOnly) libphonenumber dependency added to your app —
see phone validation.
JDK 17+ required; check your system with KDoctor. Run tests with
./gradlew :library:allTests — the JS/WasmJS tests need Chrome installed.