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

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;
}

Download Flutter Dropdown Search source code on GitHub

https://github.com/salim-lachdhaf/searchable_dropdown

Check out Flutter Dropdown Search implementation on Pub

https://pub.dev/packages/dropdown_search

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