forme 2.0.0-beta4+1

a powerful flutter form widget , for me,for you , renamed from form_builder

Screenshot

Simple Usage

add dependency

flutter pub add forme

create forme

FormeKey key = FormeKey();// formekey is a global key , also can be used to control form
Widget child = formContent;
Widget forme = Forme(
	key:key,
	child:child,
)

Forme Attributes

Attribute	Required	Type	Description
key	false	FormeKey	a global key, also used to control form
child	true	Widget	form content widget
readOnly	false	bool	whether form should be readOnly,default is false
onChanged	false	FormeValueChanged	listen form field's value change
initialValue	false	Map<String,dynamic>	initialValue , will override FormField's initialValue
validateErrorListener	false	ValidateErrorListener	listen form field's errorText change
onWillPop	false	WillPopCallback	Signature for a callback that verifies that it's OK to call Navigator.pop
quietlyValidate	false	bool	if this attribute is true , will not display default error text

Differences Between Form and Forme

Forme is a form widget, but forme is not wrapped in a Form , because I don't want to refresh whole form after field's value changed or a validate performed , so it is a bit more complexable than Form.

Difference	Form	Forme
AutovalidateMode	support both Form and field	only support field
onChanged	won't fired if value changed via state.didChange or state.setValue	fired whenever field's value changed
rebuild strategy	when field value changed or perform a validation on field , all form fields will be rebuilded	only rebuild field that value changed or validated

Forme Fields

field type

-StatefulField
	- ValueField
		- NonnullValueField
	- CommonField

attributes supported by all statefule fields

Attribute	Required	Type	Description
name	false	String	field's id,should be unique in form
builder	true	FieldContentBuilder	build field content
readOnly	false	bool	whether field should be readOnly,default is false
focusListener	false	FocusListener	listen field's focus change
model	true	FormeModel	FormeModel used to provider widget render data

attributes supported by all value fields

Attribute	Required	Type	Description
onChanged	false	FormeFieldValueChanged	listen field's value change
validateErrorListener	false	ValidateErrorListener	listen field's errorText change
validator	false	FormFieldValidator	validate field's value
autovalidateMode	false	AutovalidateMode	auto validate mode , default is AutovalidateMode.disabled
initialValue	false	dynamic	initialValue,can be overwritten by forme's initialValue
onSaved	false	FormFieldSetter	triggered when call forme or field's save method

attributes supported by all nonnull value fields

Attribute	Required	Type	Description
onChanged	false	NonnullFormeFieldValueChanged	listen field's value change
validateErrorListener	false	ValidateErrorListener	listen field's errorText change
validator	false	NonnullFieldValidator	validate field's value
autovalidateMode	false	AutovalidateMode	auto validate mode , default is AutovalidateMode.disabled
initialValue	true	dynamic	initialValue,can be overwritten by forme's initialValue
onSaved	false	NonnullFormFieldSetter	triggered when call forme or field's save method

currently supported fields

Name	Return Value	Nullable
FormeTextField	string	false
FormeDateTimeTextField	DateTime	true
FormeNumberTextField	num	true
FormeTimeTextField	TimeOfDay	true
FormeDateRangeTextField	DateTimeRange	true
FormeSlider	double	false
FormeRangeSlider	RangeValues	false
FormeFilterChip	List< T>	false
FormeChoiceChip	T	true
FormeSingleCheckbox	bool	false
FormeSingleSwitch	bool	false
FormeDropdownButton	T	true
FormeListTile	List< T>	false
FormeRadioGroup	T	true
FormeCupertinoPicker	int	false
FormeCupertinoTimerField	Duration	true
FormeCupertinoDateField	DateTime	true

Forme Model

you can update a widget easily with FormeModel

eg: if you want to update labelText of a FormeTextField, you can do this :

FormeFieldController controller = formKey.field(fieldName);
controller.update(FormeTextFieldModel(decoration:InputDecoration(labelText:'New Label')));

if you want to update items of FormeDropdownButton:

controller.updateModel(FormeDropdownButtonModel<String>(
	icon: SizedBox(
	width: 14,
	height: 14,
	child: CircularProgressIndicator(),
)));
Future<List<DropdownMenuItem<String>>> future =
	Future.delayed(Duration(seconds: 2), () {
	return FormeUtils.toDropdownMenuItems(
		['java', 'dart', 'c#', 'python', 'flutter']);
	});
future.then((value) {
controller.updateModel(FormeDropdownButtonModel<String>(
	icon: Icon(Icons.arrow_drop_down), items: value));
});

update model will auto copywith old model's attribute

Custom way display error text

if default error text display can not fit your needs , you can implementing a custom error display via ValueField's validateErrorListener or FormeValueFieldController's errorTextListenable

don't forget to set Forme's quieltyValidate attribute to true

via validateErrorListener

validateErrorListener will triggered whenever errorText of field changes , it is suitable when you want to update a stateful field according to error state of field

eg: change border color when error state changes

FormeTextField(
	validator: validator,
	validateErrorListener: (m, a) {
		InputBorder border = OutlineInputBorder(
				borderRadius: BorderRadius.circular(30.0),
				borderSide: BorderSide(color: a == null ? Colors.green : Colors.red, width: 1));
		m.updateModel(FormeTextFieldModel(
			decoration: InputDecoration(
				focusedBorder: border, enabledBorder: border)));
	},
),

via errorTextListenable

errorTextListenable is more convenient than validateErrorListener sometimes.

eg: when your want to display an valid or invalid suffix icon according to error state of field, in validateErrorListener , update model will rebuild whole field, but with errorTextListenable, you can only rebuild the suffix icon, below is an example to do this:

suffixicon: Builder(
	builder: (context) {
		FormeValueFieldController<String, FormeModel>
			controller = FormeFieldController.of(context);
		return ValueListenableBuilder<Optional<String>?>(
			valueListenable: controller.errorTextListenable,
			child: const IconButton(
				onPressed: null,
				icon: const Icon(
				Icons.check,
				color: Colors.green,
				)),
			builder: (context, errorText, child) {
			if (errorText == null)
				return SizedBox();
			else
				return errorText.isPresent
					? const IconButton(
						onPressed: null,
						icon: const Icon(
						Icons.error,
						color: Colors.red,
						))
					: child!;
			});
	},
),

you shouldn't use FormeValueFieldController's errorTextListenable out of field ,use FormfieldListenable.errorTextListenable instead

lifecycle of FormeValueFieldController's errorTextListenable is same as field,when used it on another widget , errorTextListenable will disposed before removeListener , which will cause an error in debug mode

FormfieldListenable is from formKey.fieldListenable(fieldName),it's lifecycle is same as Forme, typically used to build a widget which is not a stateful field but relies on state of field , eg: you want to display error of a field on a Text Widget

Column(
	children:[
		FormeTextField(validator:validator,name:name),
		Builder(builder:(context){
			return ValueListenableBuilder<Optional<String>?>(
				valueListenable: formeKey.fieldListenable(name).errorTextListenable,
				build: (context,errorText,child){
					return errorText == null || errorText.isNotPresent ? SizedBox() : Text(errorText.value!);
				},
			);
		})
])

Forme Field Decorator

unlike FormeTextField , some widgets , such as FormeSlider, don't have a InputDecorator , you must specific a FormeDecorator for them.

FormeDecorator's name attribute must same as field's name attribute

eg:

FormeInputDecorator(
  name: name,
  decoration: InputDecoration(labelText: 'Slider'),
  child: FormeSlider(
	min: 1,
	max: 100,
	autovalidateMode: AutovalidateMode.onUserInteraction,
	name: name,
	model: FormeSliderModel(),
	validator: (value) => value < 50
		? 'value must bigger than 50 ,current is $value'
		: null,
  ),
),

default FormeDecorator is FormeInputDecorator.

Custom Decorator

it's easily to implementing a custom decorator, below is an example:

FormeDecorator<EmptyStateModel>(
	model: EmptyStateModel(),
	name: name,
	builder: (context, a, b, c, model) {
	return Column(
		children: [
		ValueListenableBuilder<bool>(
			valueListenable: a,
			builder: (context, focus, child) {
				return Text(
				'Slider',
				style: TextStyle(
					fontSize: 30,
					color: focus
						? Colors.greenAccent
						: Colors.yellowAccent),
				);
			}),
		FormeSlider(
			min: 1,
			max: 100,
			autovalidateMode: AutovalidateMode.onUserInteraction,
			name: name,
			model: FormeSliderModel(),
			validator: (value) => value < 50
				? 'value must bigger than 50 ,current is $value'
				: null,
		),
		ValueListenableBuilder<Optional<String>?>(
			valueListenable: c,
			builder: (context, errorText, child) {
				return errorText == null || errorText.isNotPresent
					? const SizedBox()
					: Text(
						errorText.value!,
						style: TextStyle(color: Colors.red, fontSize: 30),
					);
			}),
		],
	);
	},
),

FormeKey Methods

whether form has a name field

bool hasField = formeKey.hasField(String name);

whether current form is readOnly

bool readOnly = formeKey.readOnly;

set readOnly

formeKey.readOnly = bool readOnly;

get field's controller

T controller = formeKey.field<T extends FormeFieldController>(String name);

get value field's controller

T controller = formeKey.valueField<T extends FormeValueFieldController>(String name);

get form data

Map<String, dynamic> data = formeKey.data;

validate

List<FormeFieldControllerWithError> errors = formKey.validate({bool quietly = false});

set form data

formeKey.data = Map<String,dynamic> data;// equals to formeKey.setData(data,trigger:true)
formKey.setData(Map<String,dynamic> data,{bool trigger}) // if trigger is true,will trigger fields' onChanged listener

reset form

formeKey.reset();

save form

formeKey.save();

whether validate is quietly

bool quietlyValidate = formKey.quietlyValidate;

set quietlyValidate

formeKey.quieltyValidate = bool quietlyValidate;

Forme Field Methods

get forme controller

FormeController formeController = field.controller;

get field's name

String? name = field.name

whether current field is readOnly

bool readOnly = field.readOnly;

set readOnly on field

field.readOnly = bool readOnly;

whether current field is focusable

bool focusable = field.focusable;

whether current field is focusd

bool hasFocus = field.hasFocus;

focus|unfocus current Field

field.focus = bool focus;

set field model

field.model = FormeModel model;

update field model

field.updateModel(FormeModel model);

get field model

FormeModel model = field.model;

ensure field is visible in viewport

Future<void> result = field.ensureVisibe({Duration? duration,
      Curve? curve,
      ScrollPositionAlignmentPolicy? alignmentPolicy,
      double? alignment});

get focusListenable

FormeValueListenable<bool> focusListenable = field.focusListenable;

Forme Value Field Methods

FormeValueFieldController is extended FormeFieldController

get field value

dynamic value = valueField.value;

set field value

valueField.value = dynamic data;// equals to formeKey.setData(data,trigger:true)
valueField.setValue(dynamic data,{bool trigger}) // if trigger is true,will trigger fields' onChanged listener

reset field

valueField.reset();

validate field

String? errorText = valueField.validate({bool quietly = false});

get errorText

String? errorText = valueField.errorText;

save field

valueField.save();

get decorator controller

FormeDecoratorController<T>? decoratorController = 
      valueField.getFormeDecoratorController<T extends FormeModel>();

get errorTextListenable

FormeValueListenable<Optional<String>?>  errorTextListenable = valueField.errorTextListenable;

get valueListenable

FormeValueListenable<dynamic> valueListenable = valueField.valueListenable;

build your field

1. create your FormeModel , if you don't need it , use FormeEmptyModel instead
2. create your ValueField<T,E>|NonnullValueField<T,E> , T is your field return value's type, E is your FormeModel's type
3. if you want to create your custom State,extends ValueFieldState|NonnullValueFieldState

links below is some examples to help you to build your field

common field

1. https://github.com/wwwqyhme/forme/blob/main/lib/src/field/forme_visible.dart
2. https://github.com/wwwqyhme/forme/blob/main/lib/src/field/forme_flex.dart

value field

1. https://github.com/wwwqyhme/forme/blob/main/lib/src/field/forme_filter_chip.dart
2. https://github.com/wwwqyhme/forme/blob/main/lib/src/field/forme_radio_group.dart

nonnull value field

1. https://github.com/wwwqyhme/forme/blob/main/lib/src/field/forme_list_tile.dart
2. https://github.com/wwwqyhme/forme/blob/main/lib/src/field/forme_slider.dart