FormBuilderField<T> class Null safety

A single form field.

This widget maintains the current state of the form field, so that updates and validation errors are visually reflected in the UI.



FormBuilderField({Key? key, FormFieldSetter<T>? onSaved, T? initialValue, AutovalidateMode autovalidateMode = AutovalidateMode.onUserInteraction, bool enabled = true, FormFieldValidator<T>? validator, required FormFieldBuilder<T> builder, required String name, ValueTransformer<T?>? valueTransformer, ValueChanged<T?>? onChanged, InputDecoration decoration = const InputDecoration(), VoidCallback? onReset, FocusNode? focusNode})
Creates a single form field.


autovalidateMode AutovalidateMode
Used to enable/disable this form field auto validation and update its error text. [...]
final, inherited
builder FormFieldBuilder<T>
Function that returns the widget representing this form field. It is passed the form field state as input, containing the current value and validation state of this field.
final, inherited
decoration InputDecoration
The border, labels, icons, and styles used to decorate the field.
enabled bool
Whether the form is able to receive user input. [...]
final, inherited
focusNode FocusNode?
An optional focus node to use as the focus node for this widget. [...]
hashCode int
The hash code for this object. [...]
@nonVirtual, read-only, inherited
initialValue → T?
An optional value to initialize the form field to, or null otherwise.
final, inherited
key Key?
Controls how one widget replaces another widget in the tree. [...]
final, inherited
name String
Used to reference the field within the form, or to reference form data after the form is submitted.
onChanged ValueChanged<T?>?
Called when the field value is changed.
onReset VoidCallback?
Called when the field value is reset.
onSaved FormFieldSetter<T>?
An optional method to call with the final value when the form is saved via
final, inherited
restorationId String?
Restoration ID to save and restore the state of the form field. [...]
final, inherited
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited
validator FormFieldValidator<T>?
An optional method that validates an input. Returns an error string to display if the input is invalid, or null otherwise. [...]
final, inherited
valueTransformer ValueTransformer<T?>?
Called just before field value is saved. Used to massage data just before committing the value. [...]


createElement() StatefulElement
Creates a StatefulElement to manage this widget's location in the tree. [...]
createState() FormBuilderFieldState<FormBuilderField<T>, T>
Creates the mutable state for this widget at a given location in the tree. [...]
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children. [...]
@protected, inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node. [...]
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep. [...]
toString({DiagnosticLevel minLevel =}) String
A string representation of this object. [...]
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a string representation of this node and its descendants. [...]
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) String
Returns a one-line detailed description of the object. [...]
toStringShort() String
A short, textual description of this widget.


operator ==(Object other) bool
The equality operator. [...]
@nonVirtual, inherited