forms/com.nwagu.forms/FormField

FormField

class FormField<T>(val required: Boolean = true, initialValue: T? = null) : MutableStateFlow<T?>

A FormField is a MutableStateFlow, so it can be collected and its value updated like any other MutableStateFlow.

But it also has parameters that make it suitable for use in a form, such as validators, error stateflow, feedback stateflow, and focus request.

Form field validators are run in the order they are added to the form field. If a validator fails, the remaining validators are not run. If you make use of the feedback property, it might be best practice to add only one validator.

Parameters

required

Whether this form field is optional or not. If true, the form field value is required to be non-null or non-empty to be validated. If false, the field value is optional and will be valid if it is empty or null.

Note that if required is false and the value of this form field is neither null nor empty, the field will be validated as if it were required.

initialValue

The initial value of this form field. Would typically be null or an empty string unless the form field is pre-filled (no pun intended).

Constructors

FormField

constructor(required: Boolean = true, initialValue: T? = null)

Properties

error

val error: StateFlow<String?>

errorReportingEnabled

var errorReportingEnabled: Boolean

If this is false, the form field's error state flow value will always be null.

feedback

val feedback: StateFlow<Any?>

focusRequest

val focusRequest: SharedFlow<Unit>

This emits a Unit value when the field is to be brought to the user's attention.

isValid

val isValid: Boolean

Whether the form field is valid or not.

replayCache

open override val replayCache: List<T?>

required

val required: Boolean = true

subscriptionCount

open override val subscriptionCount: StateFlow<Int>

value

open override var value: T?

Functions

addTo

fun addTo(form: Form)

Convenient method to add this form field to a form.

addValidator

fun addValidator(validator: Validator<T?>)

Add multiple validators to this form field.

addValidators

fun addValidators(vararg validators: Validator<T?>)

Add multiple validators to this form field.

collect

open suspend override fun collect(collector: FlowCollector<T?>): Nothing

compareAndSet

open override fun compareAndSet(expect: T?, update: T?): Boolean

emit

open suspend override fun emit(value: T?)

observe

fun <T> FormField<T>.observe(scope: CoroutineScope, onValueChanged: (T?) -> Unit = {}, onFeedback: (Any?) -> Unit = {}, onError: (String?) -> Unit = {}, onFocusRequest: () -> Unit = {})

resetReplayCache

open override fun resetReplayCache()

tryEmit

open override fun tryEmit(value: T?): Boolean