This package helps in creation of Flutter Forms by providing the syntactic sugar for creating a Form Widget and reduce the boilerplate needed to build a form, validate fields, react to changes, and collect the value of the Form.
To use this plugin, add flutter_form_builder
as a dependency in your pubspec.yaml file.
final GlobalKey<FormBuilderState> _fbKey = GlobalKey<FormBuilderState>();
Note: Avoid defining the GlobalKey inside your build method because this will create a new GlobalKey on every build cycle bringing about some erratic behavior.
Column(
children: <Widget>[
FormBuilder(
key: _fbKey,
initialValue: {
'date': DateTime.now(),
'accept_terms': false,
},
autovalidate: true,
child: Column(
children: <Widget>[
FormBuilderDateTimePicker(
attribute: "date",
inputType: InputType.date,
format: DateFormat("yyyy-MM-dd"),
decoration:
InputDecoration(labelText: "Appointment Time"),
),
FormBuilderSlider(
attribute: "slider",
validators: [FormBuilderValidators.min(6)],
min: 0.0,
max: 10.0,
initialValue: 1.0,
divisions: 20,
decoration:
InputDecoration(labelText: "Number of things"),
),
FormBuilderCheckbox(
attribute: 'accept_terms',
label: Text(
"I have read and agree to the terms and conditions"),
validators: [
FormBuilderValidators.requiredTrue(
errorText:
"You must accept terms and conditions to continue",
),
],
),
FormBuilderDropdown(
attribute: "gender",
decoration: InputDecoration(labelText: "Gender"),
// initialValue: 'Male',
hint: Text('Select Gender'),
validators: [FormBuilderValidators.required()],
items: ['Male', 'Female', 'Other']
.map((gender) => DropdownMenuItem(
value: gender,
child: Text("$gender")
)).toList(),
),
FormBuilderTextField(
attribute: "age",
decoration: InputDecoration(labelText: "Age"),
validators: [
FormBuilderValidators.numeric(),
FormBuilderValidators.max(70),
],
),
FormBuilderSegmentedControl(
decoration:
InputDecoration(labelText: "Movie Rating (Archer)"),
attribute: "movie_rating",
options: List.generate(5, (i) => i + 1)
.map(
(number) => FormBuilderFieldOption(value: number))
.toList(),
),
FormBuilderSwitch(
label: Text('I Accept the tems and conditions'),
attribute: "accept_terms_switch",
initialValue: true,
),
FormBuilderStepper(
decoration: InputDecoration(labelText: "Stepper"),
attribute: "stepper",
initialValue: 10,
step: 1,
),
FormBuilderRate(
decoration: InputDecoration(labelText: "Rate this form"),
attribute: "rate",
iconSize: 32.0,
initialValue: 1,
max: 5,
),
FormBuilderCheckboxList(
decoration:
InputDecoration(labelText: "The language of my people"),
attribute: "languages",
initialValue: ["Dart"],
options: [
FormBuilderFieldOption(value: "Dart"),
FormBuilderFieldOption(value: "Kotlin"),
FormBuilderFieldOption(value: "Java"),
FormBuilderFieldOption(value: "Swift"),
FormBuilderFieldOption(value: "Objective-C"),
],
),
FormBuilderChoiceChip(
attribute: "favorite_ice_cream",
options: [
FormBuilderFieldOption(
child: Text("Vanilla"),
value: "vanilla"
),
FormBuilderFieldOption(
child: Text("Chocolate"),
value: "chocolate"
),
FormBuilderFieldOption(
child: Text("Strawberry"),
value: "strawberry"
),
FormBuilderFieldOption(
child: Text("Peach"),
value: "peach"
),
],
),
FormBuilderFilterChip(
attribute: "pets",
options: [
FormBuilderFieldOption(
child: Text("Cats"),
value: "cats"
),
FormBuilderFieldOption(
child: Text("Dogs"),
value: "dogs"
),
FormBuilderFieldOption(
child: Text("Rodents"),
value: "rodents"
),
FormBuilderFieldOption(
child: Text("Birds"),
value: "birds"
),
],
),
FormBuilderSignaturePad(
decoration: InputDecoration(labelText: "Signature"),
attribute: "signature",
height: 100,
),
],
),
),
Row(
children: <Widget>[
MaterialButton(
child: Text("Submit"),
onPressed: () {
if (_fbKey.currentState.saveAndValidate()) {
print(_fbKey.currentState.value);
}
},
),
MaterialButton(
child: Text("Reset"),
onPressed: () {
_fbKey.currentState.reset();
},
),
],
)
],
)
The currently supported fields include:
FormBuilderCheckbox
- Single Checkbox fieldFormBuilderCheckboxList
- List of Checkboxes for multiple selectionFormBuilderChoiceChip
- Creates a chip that acts like a radio button.FormBuilderFilterChip
- Creates a chip that acts like a checkbox.FormBuilderChipsInput
- Takes a list ofChip
s as input and suggests more options on typingFormBuilderColorPicker
- ForColor
input selectionFormBuilderDateRangePicker
- For selection of a range of datesFormBuilderDateTimePicker
- ForDate
,Time
andDateTime
inputFormBuilderDropdown
- Used to select one value from a list as a DropdownFormBuilderRadio
- Used to select one value from a list of Radio WidgetsFormBuilderRangeSlider
- Used to select a range from a range of valuesFormBuilderRate
- For selection of a numerical value as a ratingFormBuilderSegmentedControl
- For selection of a value from theCupertinoSegmentedControl
as an inputFormBuilderSignaturePad
- Presents a drawing pad on which user can doodleFormBuilderSlider
- For selection of a numerical value on a slider- Selection of a number by tapping on a plus or minus symbol. Deprecated; replace withFormBuilderStepper
FormBuilderTouchSpin
FormBuilderSwitch
- On/Off switchFormBuilderTextField
- For text input. Accepts input of single-line text, multi-line text, password, email, urls etc by using different configurations and validatorsFormBuilderTouchSpin
- Selection of a number by tapping on a plus or minus iconFormBuilderTypeAhead
- Auto-completes user input from a list of items
In order to create an input field in the form, along with the label, and any applicable validation, there are several attributes that are supported by all types of inputs namely:
Attribute | Type | Default | Required | Description |
---|---|---|---|---|
attribute |
String |
null |
true |
This will form the key in the form value Map |
initialValue |
dynamic |
null |
false |
The initial value of the input field |
readOnly |
bool |
false |
false |
Determines whether the field widget will accept user input. This value will be ignored if the readOnly attribute of FormBuilder widget is set to true |
decoration |
InputDecoration |
InputDecoration() |
false |
|
validators |
List<FormFieldValidator> |
[] |
false |
List of FormFieldValidator s that will check the validity of value candidate in the FormField |
onChanged |
ValueChanged<T> |
null |
false |
This event function will fire immediately the the field value changes |
valueTransformer |
ValueTransformer<T> |
null |
false |
Function that transforms field value before saving to form value. e.g. transform TextField value for numeric field from String to num |
The rest of the attributes will be determined by the type of Widget being used. |
To build your own field within a FormBuilder
, we use FormBuilderCustomField
which will require that you define your own FormField
.
The FormField
will not require a validator
if the validators
property is already defined in the FormBuilderCustomField
.
FormBuilderCustomField(
attribute: "name",
validators: [
FormBuilderValidators.required(),
],
formField: FormField(
enabled: true,
builder: (FormFieldState<dynamic> field) {
return InputDecorator(
decoration: InputDecoration(
labelText: "Select option",
errorText: field.errorText,
contentPadding:
EdgeInsets.only(top: 10.0, bottom: 0.0),
border: InputBorder.none,
),
child: DropdownButton(
isExpanded: true,
items: ["One", "Two"].map((option) {
return DropdownMenuItem(
child: Text("$option"),
value: option,
);
}).toList(),
value: field.value,
onChanged: (value) {
field.didChange(value);
},
),
);
},
),
),
The validators
attribute in fields take in any number of FormFieldValidator
allowing composability
of validation functions as well as allow reusability of already defined validator methods.
The package comes with several most common FormFieldValidator
s such as required, numeric, mail, URL, min,
max, minLength, maxLength, IP, credit card etc. with default errorText
in English but with
ability to include you own error message that will display whenever validation fails.
Available built-in validators include:
FormBuilderValidators.required()
- requires the field have a non-empty value.FormBuilderValidators.numeric()
- requires the field's value to be a valid number.FormBuilderValidators.min()
- requires the field's value to be greater than or equal to the provided number.FormBuilderValidators.max()
- requires the field's value to be less than or equal to the provided number.FormBuilderValidators.minLength()
- requires the length of the field's value to be greater than or equal to the provided minimum length.FormBuilderValidators.maxLength()
- requires the length of the field's value to be less than or equal to the provided maximum length.FormBuilderValidators.pattern()
- requires the field's value to match the provided regex pattern.FormBuilderValidators.email()
- requires the field's value to be a valid email address.FormBuilderValidators.url()
- requires the field's value to be a valid url.FormBuilderValidators.IP()
- requires the field's value to be a valid IP address.FormBuilderValidators.creditCard()
- requires the field's value to be a valid credit card number.FormBuilderValidators.date()
- requires the field's value to be a valid date string.FormBuilderValidators.requiredTrue()
- requires the field's value be true.
Validation example:
FormBuilderTextField(
attribute: "age",
decoration: InputDecoration(labelText: "Age"),
validators: [
FormBuilderValidators.numeric(errorText: "La edad debe ser numérica."),
FormBuilderValidators.max(70),
],
),
As well as the built-in validators any function of type FormFieldValidator
will be accepted into the list of validators
.
FormBuilderTextField(
attribute: "over_18",
decoration: InputDecoration(labelText: "Are you over 18?"),
validators: [
FormBuilderValidators.required(),
(val){
if(val.toLowerCase() != "yes")
return "The answer must be Yes";
},
],
),
You can also validate a field based on the value of another field
FormBuilderRadio(
decoration: InputDecoration(labelText: 'My best language'),
attribute: "best_language",
validators: [FormBuilderValidators.required()],
options: [
"Dart",
"Kotlin",
"Java",
"Swift",
"Objective-C",
"Other"
]
.map((lang) => FormBuilderFieldOption(value: lang))
.toList(growable: false),
),
FormBuilderTextField(
attribute: "specify",
decoration: InputDecoration(labelText: "If Other, please specify"),
validators: [
(val){
if(_fbKey.currentState.fields['best_language'].currentState.value == "Other" && (val == null || val.isEmpty))
return "Kindly specify your language";
},
],
),
Made with contributors-img.
This package is dependent on the following packages and plugins:
- flutter_typeahead by AbdulRahmanAlHamali
- sy_flutter_widgets by Li Shuhao
- datetime_picker_formfield by Jacob Phillips
- date_range_picker by anicdh
- validators by dart-league
- signature by 4Q s.r.o. with some minor improvements to fit our usage
- flutter_colorpicker by mchome
- flutter_chips_input & flutter_touch_spin by Yours trully :-)
- Allow addition of custom input types
- Improve documentation by showing complete list of input types and their usage and options
- Create a
transformer
function option that will convert field value when field is saved - can be used to convert string to number, change to uppercase etc. - Assert no duplicates in
FormBuilderInput
sattribute
names - Allow options for Checkboxes and Radios to appear left or right - Done via
leadingInput
courtesy of Sven Schöne - For RangeSlider use Flutter provided
- Use flutter_touch_spin for FormBuilderStepper. Possibly rename to FormBuilderTouchSpin in next major version
- RangeSlider
- SignaturePad - Based on https://pub.dev/packages/signature
- ColorPicker - https://pub.dev/packages/flutter_colorpicker
- DateRangePicker - https://pub.dev/packages/date_range_picker
- FilePicker (Images & Files) -> Found here. Work in progress
- MapInput - Help Wanted
Form's reset()
doesn't clear SignaturePad - You'll be forced to clear manually
If this package was helpful to you in delivering on your project or you just wanna to support this project, a cup of coffee would be highly appreciated ;-)