# flutter_form_builder **Repository Path**: hou23/flutter_form_builder ## Basic Information - **Project Name**: flutter_form_builder - **Description**: No description available - **Primary Language**: Unknown - **License**: BSD-2-Clause - **Default Branch**: master - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 0 - **Forks**: 0 - **Created**: 2020-12-05 - **Last Updated**: 2020-12-16 ## Categories & Tags **Categories**: Uncategorized **Tags**: None ## README [![Buy me a coffee](https://www.buymeacoffee.com/assets/img/custom_images/purple_img.png)](https://buymeacoff.ee/wb5M9y2Sz) # Flutter FormBuilder - flutter_form_builder This package helps in creation of data collection forms in Flutter by removing the boilerplate needed to build a form, validate fields, react to changes, and collect final user input. [![Pub Version](https://img.shields.io/pub/v/flutter_form_builder?logo=flutter&style=for-the-badge)](https://pub.dev/packages/flutter_form_builder) [![GitHub Workflow Status](https://img.shields.io/github/workflow/status/danvick/flutter_form_builder/CI?logo=github&style=for-the-badge)](https://github.com/danvick/flutter_form_builder/actions?query=workflow%3ACI) [![Codecov](https://img.shields.io/codecov/c/github/danvick/flutter_form_builder?logo=codecov&style=for-the-badge)](https://codecov.io/gh/danvick/flutter_form_builder/) [![CodeFactor Grade](https://img.shields.io/codefactor/grade/github/danvick/flutter_form_builder?logo=codefactor&style=for-the-badge)](https://www.codefactor.io/repository/github/danvick/flutter_form_builder) [![GitHub](https://img.shields.io/github/license/danvick/flutter_form_builder?logo=open+source+initiative&style=for-the-badge)](https://github.com/danvick/flutter_form_builder/blob/master/LICENSE) [![OSS Lifecycle](https://img.shields.io/osslifecycle/danvick/flutter_form_builder?style=for-the-badge)](#support) [![Gitter](https://img.shields.io/gitter/room/danvick/flutter_form_builder?logo=gitter&style=for-the-badge)](https://gitter.im/flutter_form_builder/community?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge) ## Simple Usage To use this plugin, add `flutter_form_builder` as a [dependency in your pubspec.yaml file](https://flutter.io/platform-plugins/). ### Migrating from v3 to v4 Improvements: * Internationalized default error texts for inbuilt validators - Help wanted to do even more in translating to more languages. * Ability to programmatically induce an error to a field - could be especially useful for server-side validation. * New field types including: SearchableDropdown and FilePickerField * Better composition of validators. Breaking changes: * Rename `attribute` option in all fields to `name`. * `validators` attribute has been renamed to `validator` which takes Flutter's [FormFieldValidator]() object. To compose multiple `FormFieldValidator`s together, use `FormBuilderValidators.compose()` which takes a list of `FormFieldValidator` objects. * `FormBuilderValidators.requiredTrue` functionality has been replaced with `FormBuilderValidators.equal` which can be used to check equality of any `Object` or value * Due to its limited use, `FormBuilderCountryPicker` was removed from the package. Its functionality could be achieved with use of `FormBuilderSearchableDropdown` which is more extensible. * `FormBuilderCustomField` functionality is now achieved using `FormBuilderField` class which is the base class from which all fields are built in v4. Follow [these instructions](#building-your-own-custom-field) to construct your own custom form field using `FormBuilderField`. ### Example ```dart final _formKey = GlobalKey(); @override Widget build(BuildContext context) { return Column( children: [ FormBuilder( key: _formKey, autovalidate: true, child: Column( children: [ FormBuilderFilterChip( name: 'filter_chip', decoration: InputDecoration( labelText: 'Select many options', ), options: [ FormBuilderFieldOption( value: 'Test', child: Text('Test')), FormBuilderFieldOption( value: 'Test 1', child: Text('Test 1')), FormBuilderFieldOption( value: 'Test 2', child: Text('Test 2')), FormBuilderFieldOption( value: 'Test 3', child: Text('Test 3')), FormBuilderFieldOption( value: 'Test 4', child: Text('Test 4')), ], ), FormBuilderChoiceChip( name: 'choice_chip', decoration: InputDecoration( labelText: 'Select an option', ), options: [ FormBuilderFieldOption( value: 'Test', child: Text('Test')), FormBuilderFieldOption( value: 'Test 1', child: Text('Test 1')), FormBuilderFieldOption( value: 'Test 2', child: Text('Test 2')), FormBuilderFieldOption( value: 'Test 3', child: Text('Test 3')), FormBuilderFieldOption( value: 'Test 4', child: Text('Test 4')), ], ), FormBuilderColorPickerField( name: 'color_picker', // initialValue: Colors.yellow, colorPickerType: ColorPickerType.MaterialPicker, decoration: InputDecoration(labelText: 'Pick Color'), ), FormBuilderChipsInput( decoration: InputDecoration(labelText: 'Chips'), name: 'chips_test', onChanged: _onChanged, initialValue: [ Contact('Andrew', 'stock@man.com', 'https://d2gg9evh47fn9z.cloudfront.net/800px_COLOURBOX4057996.jpg'), ], maxChips: 5, findSuggestions: (String query) { if (query.isNotEmpty) { var lowercaseQuery = query.toLowerCase(); return contacts.where((profile) { return profile.name .toLowerCase() .contains(query.toLowerCase()) || profile.email .toLowerCase() .contains(query.toLowerCase()); }).toList(growable: false) ..sort((a, b) => a.name .toLowerCase() .indexOf(lowercaseQuery) .compareTo(b.name .toLowerCase() .indexOf(lowercaseQuery))); } else { return const []; } }, chipBuilder: (context, state, profile) { return InputChip( key: ObjectKey(profile), label: Text(profile.name), avatar: CircleAvatar( backgroundImage: NetworkImage(profile.imageUrl), ), onDeleted: () => state.deleteChip(profile), materialTapTargetSize: MaterialTapTargetSize.shrinkWrap, ); }, suggestionBuilder: (context, state, profile) { return ListTile( key: ObjectKey(profile), leading: CircleAvatar( backgroundImage: NetworkImage(profile.imageUrl), ), title: Text(profile.name), subtitle: Text(profile.email), onTap: () => state.selectSuggestion(profile), ); }, ), FormBuilderDateTimePicker( name: 'date', // onChanged: _onChanged, inputType: InputType.time, decoration: InputDecoration( labelText: 'Appointment Time', ), initialTime: TimeOfDay(hour: 8, minute: 0), // initialValue: DateTime.now(), // enabled: true, ), FormBuilderDateRangePicker( name: 'date_range', firstDate: DateTime(1970), lastDate: DateTime(2030), format: DateFormat('yyyy-MM-dd'), onChanged: _onChanged, decoration: InputDecoration( labelText: 'Date Range', helperText: 'Helper text', hintText: 'Hint text', ), ), FormBuilderSlider( name: 'slider', validator: FormBuilderValidators.compose([ FormBuilderValidators.min(context, 6), ]), onChanged: _onChanged, min: 0.0, max: 10.0, initialValue: 7.0, divisions: 20, activeColor: Colors.red, inactiveColor: Colors.pink[100], decoration: InputDecoration( labelText: 'Number of things', ), ), FormBuilderCheckbox( name: 'accept_terms', initialValue: false, onChanged: _onChanged, title: RichText( text: TextSpan( children: [ TextSpan( text: 'I have read and agree to the ', style: TextStyle(color: Colors.black), ), TextSpan( text: 'Terms and Conditions', style: TextStyle(color: Colors.blue), recognizer: TapGestureRecognizer() ..onTap = () { print('launch url'); }, ), ], ), ), validator: FormBuilderValidators.compose([ FormBuilderValidators.requireTrue( context, errorText: 'You must accept terms and conditions to continue', ), ]), ), FormBuilderTextField( name: 'age', decoration: InputDecoration( labelText: 'This value is passed along to the [Text.maxLines] attribute of the [Text] widget used to display the hint text.', ), onChanged: _onChanged, // valueTransformer: (text) => num.tryParse(text), validator: FormBuilderValidators.compose([ FormBuilderValidators.required(context), FormBuilderValidators.numeric(context), FormBuilderValidators.max(context, 70), ]), keyboardType: TextInputType.number, ), FormBuilderDropdown( name: 'gender', decoration: InputDecoration( labelText: 'Gender', ), // initialValue: 'Male', allowClear: true, hint: Text('Select Gender'), validator: FormBuilderValidators.compose( [FormBuilderValidators.required(context)]), items: genderOptions .map((gender) => DropdownMenuItem( value: gender, child: Text('$gender'), )) .toList(), ), FormBuilderTypeAhead( decoration: InputDecoration( labelText: 'Country', ), name: 'country', onChanged: _onChanged, itemBuilder: (context, country) { return ListTile( title: Text(country), ); }, controller: TextEditingController(text: ''), initialValue: 'Uganda', suggestionsCallback: (query) { if (query.isNotEmpty) { var lowercaseQuery = query.toLowerCase(); return allCountries.where((country) { return country.toLowerCase().contains(lowercaseQuery); }).toList(growable: false) ..sort((a, b) => a .toLowerCase() .indexOf(lowercaseQuery) .compareTo( b.toLowerCase().indexOf(lowercaseQuery))); } else { return allCountries; } }, ), FormBuilderRadioList( decoration: InputDecoration(labelText: 'My chosen language'), name: 'best_language', onChanged: _onChanged, validator: FormBuilderValidators.compose( [FormBuilderValidators.required(context)]), options: ['Dart', 'Kotlin', 'Java', 'Swift', 'Objective-C'] .map((lang) => FormBuilderFieldOption( value: lang, child: Text('$lang'), )) .toList(growable: false), ), FormBuilderTouchSpin( decoration: InputDecoration(labelText: 'Stepper'), name: 'stepper', initialValue: 10, step: 1, iconSize: 48.0, addIcon: Icon(Icons.arrow_right), subtractIcon: Icon(Icons.arrow_left), ), FormBuilderRating( decoration: InputDecoration(labelText: 'Rate this form'), name: 'rate', iconSize: 32.0, initialValue: 1.0, max: 5.0, onChanged: _onChanged, ), ], ), ), Row( children: [ Expanded( child: MaterialButton( color: Theme.of(context).accentColor, child: Text( "Submit", style: TextStyle(color: Colors.white), ), onPressed: () { _formKey.currentState.save(); if (_formKey.currentState.validate()) { print(_formKey.currentState.value); } else { print("validation failed"); } }, ), ), SizedBox(width: 20), Expanded( child: MaterialButton( color: Theme.of(context).accentColor, child: Text( "Reset", style: TextStyle(color: Colors.white), ), onPressed: () { _formKey.currentState.reset(); }, ), ), ], ) ], ); } ``` ## l10n Just add the `FormBuilderLocalizations.delegate` in the list of your app's ` localizationsDelegates` ```dart return MaterialApp( supportedLocales: [ Locale('en'), Locale('it'), Locale('fr'), Locale('es'), ], localizationsDelegates: [ FormBuilderLocalizations.delegate, GlobalMaterialLocalizations.delegate, GlobalWidgetsLocalizations.delegate, ], ``` ## Input widgets The currently supported fields include: * `FormBuilderCheckbox` - Single Checkbox field * `FormBuilderCheckboxList` - List of Checkboxes for multiple selection * `FormBuilderChipsInput` - Takes a list of `Chip`s as input and suggests more options on typing * `FormBuilderChoiceChip` - Creates a chip that acts like a radio button. * `FormBuilderColorPicker` - For `Color` input selection * `FormBuilderDateRangePicker` - For selection of a range of dates * `FormBuilderDateTimePicker` - For `Date`, `Time` and `DateTime` input * `FormBuilderDropdown` - Used to select one value from a list as a Dropdown * `FormBuilderFilePicker` - Picks image(s) from user device storage. * `FormBuilderFilterChip` - Creates a chip that acts like a checkbox. * `FormBuilderImagePicker` - Picks image(s) from Gallery or Camera. * `FormBuilderPhoneField` - International phone number input. * `FormBuilderRadioGroup` - Used to select one value from a list of Radio Widgets * `FormBuilderRangeSlider` - Used to select a range from a range of values * `FormBuilderRating` - For selection of a numerical value as a rating * `FormBuilderSearchableDropdown` - Field for selecting value(s) from a searchable list * `FormBuilderSegmentedControl` - For selection of a value from the `CupertinoSegmentedControl` as an input * `FormBuilderSignaturePad` - Field with drawing pad on which user can doodle * `FormBuilderSlider` - For selection of a numerical value on a slider * `FormBuilderSwitch` - On/Off switch field * `FormBuilderTextField` - A Material Design text field input. * `FormBuilderTouchSpin` - Selection of a number by tapping on a plus or minus icon * `FormBuilderTypeAhead` - 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 | |-----------|-------|---------|-------------|----------| | `name` | `String` | | `Yes` | This will form the key in the form value Map | | `initialValue` | `T` | `null` | `No` | The initial value of the input field | | `enabled` | `bool` | `true` | `No` | Determines whether the field widget will accept user input. | | `decoration` | `InputDecoration` | `InputDecoration()` | `No` | Defines the border, labels, icons, and styles used to decorate the field. | | `validator` | `FormFieldValidator` | `null` | `No` | A `FormFieldValidator` that will check the validity of value in the `FormField` | | `onChanged` | `ValueChanged` | `null` | `No` | This event function will fire immediately the the field value changes | | `valueTransformer` | `ValueTransformer` | `null` | `No` | 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. ### Building your own custom field To build your own field within a `FormBuilder`, we use `FormBuilderField` which will require that you define your own field. ```dart var options = ["Option 1", "Option 2", "Option 3"]; ``` ```dart FormBuilderField( name: "name", validator: FormBuilderValidators.compose([ FormBuilderValidators.required(context), ]), builder: (FormFieldState field) { return InputDecorator( decoration: InputDecoration( labelText: "Select option", contentPadding: EdgeInsets.only(top: 10.0, bottom: 0.0), border: InputBorder.none, errorText: field.errorText, ), child: Container( height: 200, child: CupertinoPicker( itemExtent: 30, children: options.map((c) => Text(c)).toList(), onSelectedItemChanged: (index) { field.didChange(options[index]); }, ), ), ); }, ), ``` ### Programmatically changing field value You can either change the value of one field at a time like so: ```dart _formKey.currentState.fields['color_picker'].didChange(Colors.black); ``` Or multiple fields value like so: ```dart _formKey.currentState.patchValue({ 'age': '50', 'slider': 6.7, 'filter_chip': ['Test 1'], 'choice_chip': 'Test 2', 'rate': 4, 'chips_test': [ Contact('Andrew', 'stock@man.com', 'https://d2gg9evh47fn9z.cloudfront.net/800px_COLOURBOX4057996.jpg'), ], }); ``` ## Validation The `validator` attribute in fields take in a `FormFieldValidator` which checks the validity of the field. A `FormFieldValidator` returns `null` if validation is successful and a `String` for the `errorText` if validation fails. ### Built-in Validators This 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`. Available built-in validators include: * `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.email()` - requires the field's value to be a valid email address. * `FormBuilderValidators.equal()` - requires the field's value be equal to provided object. * `FormBuilderValidators.integer()` - requires the field's value to be an integer. * `FormBuilderValidators.ip()` - requires the field's value to be a valid IP address. * `FormBuilderValidators.match()` - requires the field's value to match the provided regex pattern. * `FormBuilderValidators.max()` - requires the field's value to be less than or equal to the provided number. * `FormBuilderValidators.maxLength()` - requires the length of the field's value to be less than or equal to the provided maximum length. * `FormBuilderValidators.min()` - requires the field's value to be greater 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.numeric()` - requires the field's value to be a valid number. * `FormBuilderValidators.required()` - requires the field have a non-empty value. * ``FormBuilderValidators.url()`` - requires the field's value to be a valid url. ### Using multiple validators `FormBuilderValidators` class comes with a very useful static function named `compose()` which takes any number of `FormFieldValidator` functions. On validation each validator is run and if any returns a non-null value (i.e. a String), validation fails and the `errorText` for the field is set as the returned string. Validation example: ```dart FormBuilderTextField( name: 'age', decoration: InputDecoration(labelText: 'Age'), validator: FormBuilderValidators.compose([ FormBuilderValidators.numeric(context, errorText: 'La edad debe ser numérica.'), FormBuilderValidators.max(context, 70), (val){ if(val < 0) return 'We cannot have a negative age'; return null; } ]), ), ``` ### Programmatically inducing an error Declare a variable to hold your error: ```dart String _emailError; ``` Use the variable as the `errorText` within `InputDecoration` ```dart FormBuilderTextField( name: 'email', decoration: InputDecoration( labelText: 'Email', errorText: _emailError, ), validator: FormBuilderValidators.compose([ FormBuilderValidators.required(context), FormBuilderValidators.email(context), ]), ), ``` Set the error text ```dart RaisedButton( child: Text('Submit'), onPressed: () async { setState(() => _emailError = null); if(checkIfEmailExists()){ setState(() => _emailError = 'Email already taken.'); } }, ), ``` ### Conditional validation You can also validate a field based on the value of another field ```dart FormBuilderRadioGroup( decoration: InputDecoration(labelText: 'My best language'), name: 'my_language', validator: FormBuilderValidators.required(context), options: [ 'Dart', 'Kotlin', 'Java', 'Swift', 'Objective-C', 'Other' ] .map((lang) => FormBuilderFieldOption(value: lang)) .toList(growable: false), ), FormBuilderTextField( name: 'specify', decoration: InputDecoration(labelText: 'If Other, please specify'), validator: (val) { if (_formKey.currentState.fields['my_language']?.value == 'Other' && (val == null || val.isEmpty)) { return 'Kindly specify your language'; } return null; }, ), ``` ## SUPPORT ### Issues and PRs Any kind of support in the form of reporting bugs, answering questions or PRs is always appreciated. We especially welcome efforts to internationalize/localize the package by translating the default validation `errorText` strings. ### Localizing messages 1. With the app’s root directory as the current directory, generate `l10n/intl_messages.arb` from `lib/localization/form_builder_localizations.dart`: ```flutter pub pub run intl_translation:extract_to_arb --output-dir=lib/l10n lib/localization/form_builder_localizations.dart``` 2. The `intl_messages.arb` file is a JSON format map with one entry for each `Intl.message()` function defined in `lib/localization/form_builder_localizations.dart`. This file serves as a template for the different translations (for example `intl_en.arb` and `intl_es.arb` are English and Spanish translations respectively). You are therefore you are required to copy the `intl_messages.arb` and put the content in a new file with the name of your locale with a name with format `intl_.arb` (e.g. `intl_fr.arb` for French Translations). 3. Translate the messages in the new file to the required language. 4. With the app’s root directory as the current directory, generate `intl_messages_.dart` for your `intl_.arb` file and update `intl_messages_all.dart`, which imports all of the messages files: ```flutter pub run intl_translation:generate_from_arb --output-dir=lib/l10n --no-use-deferred-loading lib/localization/form_builder_localizations.dart lib/l10n/intl_.arb lib/l10n/intl_messages.arb``` e.g. To generate for French run: ```flutter pub run intl_translation:generate_from_arb --output-dir=lib/l10n --no-use-deferred-loading lib/localization/form_builder_localizations.dart lib/l10n/intl_fr.arb lib/l10n/intl_messages.arb``` - Alternatively you could run the following command to generate Dart translation files for all the `intl_.arb` files in the `l10n/` directory: ```flutter pub pub run intl_translation:generate_from_arb --output-dir=lib/l10n --no-use-deferred-loading lib/localization/form_builder_localizations.dart lib/l10n/intl_*.arb``` 5. Include your new language to `FormBuilderLocalization`'s supported languages. Go to `lib/localization/form_builder_localizations.dart` and include the language like so: 

@override
  bool isSupported(Locale locale) {
    return ['en', 'es', 'fr'].contains(locale.languageCode);
  }
6. Submit your PR and be of help to millions of people all over the world! ### Coffee :-) If this package was helpful to you in delivering your project or you just wanna to support this package, a cup of coffee would be highly appreciated ;-) [![Buy me a coffee](https://www.buymeacoffee.com/assets/img/custom_images/purple_img.png)](https://buymeacoff.ee/wb5M9y2Sz) ## CREDITS ### Contributors Made with [contributors-img](https://contributors-img.firebaseapp.com).