Flutter DropdownSearch

Flutter simple and robust DropdownSearch with item search feature, making it possible to use an offline item list or filtering URL for easy customization.

Key Features • Examples • License

Key Features

• Online and offline items
• Searchable dropdown
• Three dropdown mode: Menu/ BottomSheet/ Dialog
• Material dropdown
• Easy customizable UI
• Handle Light and Dark theme
• Easy implementation into statelessWidget

packages.yaml

dropdown_search: <lastest version>

Import

import 'package:dropdown_search/dropdown_search.dart';

Simple implementation

DropdownSearch<String>(
    mode: Mode.MENU,
    showSelectedItem: true,
    items: ["Brazil", "Italia (Disabled)", "Tunisia", 'Canada'],
    label: "Menu mode",
    hint: "country in menu mode",
    popupItemDisabled: (String s) => s.startsWith('I'),
    onChanged: print,
    selectedItem: "Brazil"),

customize showed field (itemAsString)

DropdownSearch<UserModel>(
  label: "Name",
  onFind: (String filter) => getData(filter),
  itemAsString: (UserModel u) => u.userAsStringByName(),
  onChanged: (UserModel data) => print(data),
),

DropdownSearch<UserModel>(
  label: "Name",
  onFind: (String filter) => getData(filter),
  itemAsString: (UserModel u) => u.userAsStringById(),
  onChanged: (UserModel data) => print(data),
),

customize Filter Function

DropdownSearch<UserModel>(
  label: "Name",
  filterFn: (user, filter) => user.userFilterByCreationDate(filter),
  onFind: (String filter) => getData(filter),
  itemAsString: (UserModel u) => u.userAsStringByName(),
  onChanged: (UserModel data) => print(data),
),

customize Search Mode

DropdownSearch<UserModel>(
  mode: Mode.BOTTOM_SHEET,
  label: "Name",
  onFind: (String filter) => getData(filter),
  itemAsString: (UserModel u) => u.userAsString(),
  onChanged: (UserModel data) => print(data),
),

Validation

DropdownSearch(
  items: ["Brazil", "France", "Tunisia", "Canada"],
  label: "Country",
  onChanged: print,
  selectedItem: "Tunisia",
  validator: (String item) {
    if (item == null)
      return "Required field";
    else if (item == "Brazil")
      return "Invalid item";
    else
      return null;
  },
);

Endpoint implementation (using Dio package)

DropdownSearch<UserModel>(
  label: "Name",
  onFind: (String filter) async {
    var response = await Dio().get(
        "http://5d85ccfb1e61af001471bf60.mockapi.io/user",
        queryParameters: {"filter": filter},
    );
    var models = UserModel.fromJsonList(response.data);
    return models;
  },
  onChanged: (UserModel data) {
    print(data);
  },
);

Layout customization

You can customize the layout of the DropdownSearch and its items. EXAMPLE

Properties	Description
label	DropDownSearch label
showSearchBox	show/hide the search box
isFilteredOnline	true if the filter on items is applied onlie (via API)
showClearButton	show/hide clear selected item
items	offline items list
selectedItem	selected item
onFind	function that returns item from API
onChanged	called when a new item is selected
dropdownBuilder	to customize list of items UI
popupItemBuilder	to customize selected item
validator	function to apply the validation formula
searchBoxDecoration	decoration for the search box
popupBackgroundColor	background color for the dialog/menu/bottomSheet
popupTitle	Custom widget for the popup title
itemAsString	customize the fields the be shown
filterFn	custom filter function
enabled	enable/disable dropdownSearch
mode	MENU / DIALOG/ BOTTOM_SHEET
maxHeight	the max height for dialog/bottomSheet/Menu
dialogMaxWidth	the max width for the dialog
showSelectedItem	manage selected item visibility (if true, the selected item will be highlighted)
compareFn	Function(T item, T selectedItem), custom comparing function
dropdownSearchDecoration	DropdownSearch input decoration
emptyBuilder	custom layout for empty results
loadingBuilder	custom layout for loading items
errorBuilder	custom layout for error
autoFocusSearchBox	the search box will be focused if true
popupShape	custom shape for the popup
autoValidateMode	handle auto validation mode
onSaved	An optional method to call with the final value when the form is saved via
validator	An optional method that validates an input. Returns an error string to display if the input is invalid, or null otherwise.
clearButton	customize clear button widget
dropDownButton	customize dropdown button widget
dropdownBuilderSupportsNullItem	If true, the dropdownBuilder will continue the uses of material behavior. This will be useful if you want to handle a custom UI only if the item !=null
popupItemDisabled	defines if an item of the popup is enabled or not, if the item is disabled, it cannot be clicked
popupBarrierColor	set a custom color for the popup barrier
searchBoxController	search box controller
clearButtonBuilder	custom clear button builder
dropdownButtonBuilder	custom dropdown button builder
onBeforeChange	callback executed before applying value change
searchDelay	delay before searching

Attention

To use a template as an item type, and you don't want to use a custom fonction itemAsString and compareFn you need to implement toString, equals and hashcode, as shown below:

class UserModel {
  final String id;
  final DateTime createdAt;
  final String name;
  final String avatar;

  UserModel({this.id, this.createdAt, this.name, this.avatar});

  factory UserModel.fromJson(Map<String, dynamic> json) {
    if (json == null) return null;
    return UserModel(
      id: json["id"],
      createdAt:
          json["createdAt"] == null ? null : DateTime.parse(json["createdAt"]),
      name: json["name"],
      avatar: json["avatar"],
    );
  }

  static List<UserModel> fromJsonList(List list) {
    if (list == null) return null;
    return list.map((item) => UserModel.fromJson(item)).toList();
  }

  ///this method will prevent the override of toString
  String userAsString() {
    return '#${this.id} ${this.name}';
  }

  ///this method will prevent the override of toString
  bool userFilterByCreationDate(String filter) {
    return this?.createdAt?.toString()?.contains(filter);
  }

  ///custom comparing function to check if two users are equal
  bool isEqual(UserModel model) {
    return this?.id == model?.id;
  }

  @override
  String toString() => name;
}

View more Examples

Support

If this plugin was useful to you, helped you to deliver your app, saved you a lot of time, or you just want to support the project, I would be very grateful if you buy me a cup of coffee.

License

MIT