listflutterdartflutter-typeahead

how to do suggestionCallback in typeahead flutter?


i'm beginner in flutter, in my flutter project i used flutter_typeahead package but i did not able to execute this code.

i did not get proper guidance from this documentation https://pub.dev/documentation/flutter_typeahead/latest/flutter_typeahead/flutter_typeahead-library.html

    suggestionsCallback: (pattern) {
      return CitiesService.getSuggestions(pattern);
     }

Solution

  • The example service is here, pattern in CitiesService example means contain some characters

    https://github.com/AbdulRahmanAlHamali/flutter_typeahead/blob/master/example/lib/data.dart

    import 'dart:math';
    
    class BackendService {
      static Future<List> getSuggestions(String query) async {
        await Future.delayed(Duration(seconds: 1));
    
        return List.generate(3, (index) {
          return {'name': query + index.toString(), 'price': Random().nextInt(100)};
        });
      }
    }
    
    class CitiesService {
      static final List<String> cities = [
        'Beirut',
        'Damascus',
        'San Fransisco',
        'Rome',
        'Los Angeles',
        'Madrid',
        'Bali',
        'Barcelona',
        'Paris',
        'Bucharest',
        'New York City',
        'Philadelphia',
        'Sydney',
      ];
    
      static List<String> getSuggestions(String query) {
        List<String> matches = List();
        matches.addAll(cities);
    
        matches.retainWhere((s) => s.toLowerCase().contains(query.toLowerCase()));
        return matches;
      }
    }