CronFormField class

A CronFormField that contains a TextField.

This is a convenience widget that wraps a TextField widget in a CronFormField.

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.

When a controller is specified, its TextEditingController.text defines the initialValue. If this FormField is part of a scrolling container that lazily constructs its children, like a ListView or a CustomScrollView, then a controller should be specified. The controller's lifetime should be managed by a stateful widget ancestor of the scrolling container.

If a controller is not specified, initialValue can be used to give the automatically generated controller an initial value.

Remember to dispose of the TextEditingController when it is no longer needed. This will ensure we discard any resources used by the object.

For a documentation about the various parameters, see TextField.

{@tool snippet}

Creates a CronFormField with an InputDecoration and validator function.

If the user enters valid text, the TextField appears normally without any warnings to the user

If the user enters invalid text, the error message returned from the validator function is displayed in dark red underneath the input

CronFormField(
  decoration: const InputDecoration(
    icon: Icon(Icons.person),
    hintText: 'What do people call you?',
    labelText: 'Name *',
  ),
  onSaved: (String value) {
    // This optional block of code can be used to run
    // code when the user saves the form.
  },
  validator: (String value) {
    return value.contains('@') ? 'Do not use the @ char.' : null;
  },
)

{@end-tool}

{@tool dartpad --template=stateful_widget_material} This example shows how to move the focus to the next field when the user presses the ENTER key.

import 'package:flutter/services.dart';

Widget build(BuildContext context) {
  return Material(
    child: Center(
      child: Shortcuts(
        shortcuts: <LogicalKeySet, Intent>{
          // Pressing enter on the field will now move to the next field.
          LogicalKeySet(LogicalKeyboardKey.enter):
              Intent(NextFocusAction.key),
        },
        child: FocusTraversalGroup(
          child: Form(
            autovalidate: true,
            onChanged: () {
              Form.of(primaryFocus.context).save();
            },
            child: Wrap(
              children: List<Widget>.generate(5, (int index) {
                return Padding(
                  padding: const EdgeInsets.all(8.0),
                  child: ConstrainedBox(
                    constraints: BoxConstraints.tight(Size(200, 50)),
                    child: CronFormField(
                      onSaved: (String value) {
                        print('Value for field $index saved as "$value"');
                      },
                    ),
                  ),
                );
              }),
            ),
          ),
        ),
      ),
    ),
  );
}

{@end-tool}

See also:

Inheritance

Constructors

CronFormField({Key? key, TextEditingController? controller, Widget? icon, String? labelText, String? hintText, String? dialogTitle, String dialogCancelText = 'Cancel', String dialogDoneText = 'Done', ValueChanged<String>? onChanged, CronExpressionOutputFormat? outputFormat = CronExpressionOutputFormat.AUTO, String? initialValue, FocusNode? focusNode, InputDecoration? decoration, TextInputType? keyboardType, TextCapitalization textCapitalization = TextCapitalization.none, TextInputAction? textInputAction, TextStyle? style, StrutStyle? strutStyle, TextDirection? textDirection, TextAlign textAlign = TextAlign.start, TextAlignVertical? textAlignVertical, bool autofocus = false, bool readOnly = false, Widget contextMenuBuilder(BuildContext, EditableTextState)?, bool? showCursor, bool obscureText = false, bool autocorrect = true, SmartDashesType? smartDashesType, SmartQuotesType? smartQuotesType, bool enableSuggestions = true, bool autovalidate = false, bool maxLengthEnforced = true, int maxLines = 1, int? minLines, bool expands = false, int? maxLength, VoidCallback? onEditingComplete, ValueChanged<String>? onFieldSubmitted, FormFieldSetter<String>? onSaved, FormFieldValidator<String>? validator, List<TextInputFormatter>? inputFormatters, bool enabled = true, double cursorWidth = 2.0, Radius? cursorRadius, Color? cursorColor, Brightness? keyboardAppearance, EdgeInsets scrollPadding = const EdgeInsets.all(20.0), bool enableInteractiveSelection = true, InputCounterWidgetBuilder? buildCounter, ScrollPhysics? scrollPhysics})
Creates a CronFormField that contains a TextField.

Properties

autovalidateMode → AutovalidateMode
Used to enable/disable this form field auto validation and update its error text.
finalinherited
builder → FormFieldBuilder<String>
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.
finalinherited
controller → TextEditingController?
Controls the text being edited.
final
dialogCancelText → String
The cancel button text on dialog
final
dialogDoneText → String
The done button text on dialog
final
dialogTitle → String?
The title of the dialog window.
final
enabled → bool
Whether the form is able to receive user input.
finalinherited
forceErrorText → String?
An optional property that forces the FormFieldState into an error state by directly setting the FormFieldState.errorText property without running the validator function.
finalinherited
hashCode → int
The hash code for this object.
no setterinherited
hintText → String?
Text that suggests what sort of input the field accepts.
final
icon → Widget?
An icon to show before the input field and outside of the decoration's container.
final
initialValue → String?
An optional value to initialize the form field to, or null otherwise.
finalinherited
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
labelText → String?
Text that describes the input field.
final
onChanged → ValueChanged<String>?
The value change event
final
onSaved → FormFieldSetter<String>?
An optional method to call with the final value when the form is saved via FormState.save.
finalinherited
outputFormat → CronExpressionOutputFormat?
final
restorationId → String?
Restoration ID to save and restore the state of the form field.
finalinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
validator → FormFieldValidator<String>?
An optional method that validates an input. Returns an error string to display if the input is invalid, or null otherwise.
finalinherited

Methods

createElement() → StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → CronFormFieldState
Creates the mutable state for this widget at a given location in the tree.
override
debugDescribeChildren() → List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String
A string representation of this object.
inherited
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug, int wrapWidth = 65}) → String
Returns a string representation of this node and its descendants.
inherited
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String
Returns a one-line detailed description of the object.
inherited
toStringShort() → String
A short, textual description of this widget.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited