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.
When used inside a Form, you can use methods on FormState to query or manipulate the form data as a whole. For example, calling FormState.save will invoke each FormField's onSaved callback in turn.
Use a GlobalKey with FormField if you want to retrieve its current state, for example if you want one form field to depend on another.
A Form ancestor is not required. The Form simply makes it easier to save, reset, or validate multiple fields at once. To use without a Form, pass a GlobalKey to the constructor and use GlobalKey.currentState to save or reset the form field.
See also: Form, InputFormField
- Inheritance
- Object
- Widget
- StatefulWidget
- FormField
Constructors
- FormField({Key key, @required FormFieldBuilder<T> builder, FormFieldSetter<T> onSaved, FormFieldValidator<T> validator, T initialValue, bool autovalidate: false })
Properties
- autovalidate → bool
-
If true, this form fields will validate and update its error text immediately after every change. Otherwise, you must call FormFieldState.validate to validate. If part of a Form that autovalidates, this value will be ignored.
read-only - 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.
read-only - initialValue → T
-
An optional value to initialize the form field to, or null otherwise.
read-only - onSaved → FormFieldSetter<T>
-
An optional method to call with the final value when the form is saved via Form.save().
read-only - validator → FormFieldValidator<T>
-
An optional method that validates an input. Returns an error string to display if the input is invalid, or null otherwise.
read-only - hashCode → int
-
Get a hash code for this object.
read-only, inherited - key → Key
-
Controls how one widget replaces another widget in the tree.
read-only, inherited - runtimeType → Type
-
A representation of the runtime type of the object.
read-only, inherited
Operators
-
operator ==(
other) → bool -
The equality operator.
inherited
Methods
-
createState(
) → FormFieldState<T> -
Creates the mutable state for this widget at a given location in the tree.
-
createElement(
) → StatefulElement -
Creates a StatefulElement to manage this widget's location in the tree.
inherited -
debugFillDescription(
List<String> description) → void -
Add additional information to the given description for use by toString.
inherited -
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent method or property is accessed.
inherited -
toString(
) → String -
Returns a string representation of this object.
inherited -
toStringShort(
) → String -
A short, textual description of this widget.
inherited