forme 2.0.4

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
onValueChanged	false	FormeValueChanged	listen form field's value change
initialValue	false	Map<String,dynamic>	initialValue , will override FormField's initialValue
onErrorChanged	false	FormeErrorChanged	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
onFocusChanged	false	FormeFocusChanged	listen form field's focus change

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
	- CommonField

attributes supported by all stateful fields

Attribute	Required	Type	Description
name	true	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
onFocusChanged	false	FormeFocusChanged	listen field's focus change
model	true	FormeModel	FormeModel used to provider widget render data
onInitialed	false	FormeFieldInitialed	triggered when FormeFieldController initialed , when you specific a initialValue on ValueField or Forme , valueListenable will not listen this value , you can handle this value in onInitialed

attributes supported by all value fields

Attribute	Required	Type	Description
onValueChanged	false	FormeValueChanged	listen field's value change
onErrorChanged	false	FormeErrorChanged	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
decoratorBuilder	false	FormeDecoratorBuilder	used to decorate a field

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
FormeCupertinoSegmentedControl	T	true
FormeCupertinoSlidingSegmentedControl	T	true
FormeAsnycAutocompleteChip	List<T>	false
FormeAsnycAutocompleteText	T	true
FormeAutocompleteText	T	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 onErrorChanged or FormeValueFieldController's errorTextListenable

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

via onErrorChanged

onErrorChanged 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,
	onErrorChanged: (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 onErrorChanged sometimes.

eg: when your want to display an valid or invalid suffix icon according to error state of field, in onErrorChanged , 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<FormeValidateError?>(
			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<FormeValidateError?>(
				valueListenable: formeKey.fieldListenable(name).errorTextListenable,
				build: (context,errorText,child){
					return errorText == null || errorText.isNotPresent ? SizedBox() : Text(errorText.value!);
				},
			);
		})
])

listenable

there are five listenables in field

1. focusListenable
2. readOnlyListenable
3. errorTextListenable
4. valueListenable
5. modelListenable

get listenable from FormeFieldController

you can get focusListenable and readOnlyListenable from FormeFieldController, get valueListenable and errorTextListenable from FormeValueFieldController

these listenables lifecycle is same as field , so you can't use them out of field (you will get a changenotifier was used after being disposed error)

right way use these listenables

FormeTextField(
	decoratorBuilder:FormeDecoratorBuilder(),//decorator is a part of field 
	mode:FormeTextFieldModel(
		decoration:InputDecoration(
			suffixIcon: Builder(builder: (context) {
				FormeFieldController controller = FormeFieldController.of(context);
				return ValueListenable<bool>(valueListenable:controller.		valueListenable,builder:(context,focus,child){
					if(focus) return Icon(Icons.clear);
					return SizedBox();
				})
			}),
		),
	),
)

get listenable from FormeController

you can get FormeFieldListenable via FormeController.fieldListenable(String fieldName) , this listenable's lifecycle is same as Forme ,it's safe to use it out of field but in Forme.

FormeFieldListenable's valueListenable doesn't support generic type due to field's type may be changed at runtime though this shouldn't happend

when field disposed and recreated but name not changed, these listenables will continue listen this field

get listenable from FormeKey

you can get a LazyFormeFieldListenable via FormeKey.lazyFieldListenable(name).

LazyFormeFieldListenable's behavior is same as FormeFieldListenable,the difference is LazyFormeFieldListenable no need to wrap in a Builder or other widgets and not support modelListenable.

eg:

Forme(
	key:formeKey,
	child:Column(
		children:[
			ValueListenableBuilder(valueListenable:formeKey.fieldListenable(name)),//will cause an error
			Builder(builder:(context){
				return ValueListenableBuilder(valueListenable:formeKey.fieldListenable(name));
			}),//will works
			ValueListenableBuilder(valueListenable:formeKey.lazyFieldListenable(name)),//will works
		]
	)
)

validate

validate is supported by FormeValidateUtils

Validator Name	Support Type	When Valid	When Invalid
notNull	dynamic	value is not null	value is null
size	Iterable Map String	1. value is null 2. max & min is null 3. String's length or Collection's size is in [min,max]	String's length or Collection's size is not in [min,max]
min	num	1. value is null 2. value is bigger than min	value is smaller than min
max	num	1. value is null 2. value is smaller than max	value is bigger than max
notEmpty	Iterable Map String	1. value is not null 2. String's length or Collection's size is bigger than zero	1. value is null 2. String's length or Collection's size is zero
notBlank	String	1. value is null 2. value.trim()'s length is not null	value'length is zero after trimed
positive	num	1. value is null 2. value is bigger than zero	value is smaller than or equals zero
positiveOrZero	num	1. value is null 2. value is bigger than or equals zero	value is smaller than zero
negative	num	1. value null 2. value is smaller than zero	value is bigger than or equals zero
negativeOrZero	num	1. value null 2. value is smaller than or equals zero	value is bigger than zero
pattern	String	1. value null 2. value matches pattern	value does not matches pattern
email	String	1. value null 2. value is a valid email	value is not a valid email
url	String	1. value is null 2. value is empty or value is a valid url	value is not a valid url
any	T	any validators is valid	every validators is invalid
all	T	all validators is valid	any validators is invalid

when you use validators from FormeValidateUtils , you must specific at least one errorText , otherwise errorText is an empty string

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

Map<FormeValueFieldController,String> errors = formKey.validate({bool quietly = false});

set form data

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

reset form

formeKey.reset();

save form

formeKey.save();

whether validate is quietly

bool quietlyValidate = formKey.quietlyValidate;

set quietlyValidate

formeKey.quieltyValidate = bool quietlyValidate;

get a lazy FormeFieldListenable

FormeFieldListenable listenable = formeKey.lazyFieldListenable(String name);

Forme Field Methods

get forme controller

FormeController formeController = field.formeController;

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 focused

bool hasFocus = field.hasFocus;

focus|unfocus current Field

field.requestFocus();
field.unfocus();

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

ValueListenable<bool> focusListenable = field.focusListenable;

get readOnlyListenable

ValueListenable<bool> readOnlyListenable = field.readOnlyListenable;

Forme Value Field Methods

FormeValueFieldController is extended FormeFieldController

get field value

dynamic value = valueField.value;

set field value

valueField.value = dynamic data;

reset field

valueField.reset();

validate field

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

get error

FormeValidateError? error = valueField.error;

get decorator controller

FormeDecoratorController decoratorController = valueField.decoratorController;

get errorTextListenable

ValueListenable<FormeValidateError?>  errorTextListenable = valueField.errorTextListenable;

get valueListenable

ValueListenable<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> , 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<T,E>

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