How to get selected chip choice values in flutter

Question

I've searched a lot on the internet but couldn't find the exact solution. How to get a list of selected Chips items I am passing the list of the object for option list values but unable to get the index of the selected item in onChanged method

          Container(
            child: FormField<List<Hashtag>>(
              autovalidate: true,
              initialValue: hashtagSelectedList,
              onSaved: (value) {
                Utility.showToast(value.toString());
                //hashtagSelectedList[0].hashtag = value.toString();
              },
              validator: (value) {
                if (value.isEmpty) {
                  return 'Please select some categories';
                }
                if (value.length > 5) {
                  return "Can't select more than 5 categories";
                }
                return null;
              },
              builder: (state) {
                return Column(
                  children: <Widget>[
                    Container(
                      alignment: Alignment.centerLeft,
                      child: ChipsChoice<Hashtag>.multiple(
                        value: state.value,
                        options: ChipsChoiceOption.listFrom<Hashtag, Hashtag>(
                          source: _hashtags,
                          value: (i, v) => v,
                          label: (i, v) => v.hashtag.toString(),
                        ),
                        onChanged: (val) {
                          if (val.length > 5) {
                            Utility.showToast(
                                "Can't select more than 5 categories");
                            return;
                          }
                          state.didChange(val);
                        },
                        itemConfig: ChipsChoiceItemConfig(
                          showCheckmark: false,
                          selectedColor: Colors.indigo,
                          selectedBrightness: Brightness.dark,
                          unselectedColor: Colors.indigo,
                          unselectedBorderOpacity: .3,
                        ),
                        isWrapped: true,
                      ),
                    ),
                    Container(
                        padding: EdgeInsets.fromLTRB(15, 0, 15, 15),
                        alignment: Alignment.centerLeft,
                        child: Text(
                          state.errorText ?? state.value.toString(),
                          style: TextStyle(
                              color: state.hasError
                                  ? Colors.redAccent
                                  : Colors.green),
                        )),
                  ],
                );
              },
            ),
          ),

 Option list - List<Hashtag> _hashtags; 
 Initial list - List<Hashtag> hashtagSelectedList; 

Model -
   class Hashtag {
   int id;
   String hashtag;
  int status;
  bool isSelected = false;

  Hashtag();

  Hashtag.fromJson(Map<String, dynamic> json) {
    id = json[ApiKeys.id] ?? 0;
    hashtag = json[ApiKeys.hashtag] ?? '';
    status = json[ApiKeys.status] ?? 0;
  }
}

Please give me solutions 

Answer 1

Abhijit Rajmane Try this for your case:

List<Category> _selectedCats = [];
  List<Category> _categories = [
    new Category(id: "001", name: "Cat 001"),
    new Category(id: "002", name: "Cat 002"),
    new Category(id: "003", name: "Cat 003"),
  ];

Widget for the given categories:

Container(
      child: ChipsChoice<Category>.multiple(
          value: _selectedCats,
          options: ChipsChoiceOption.listFrom<Category, Category>(
            source: _categories,
            value: (i, v) => v,
            label: (i, v) => v.name,
          ),
          onChanged: (val) {
            //val.forEach((category) {
            //  print("${category.id} - ${category.name}");
            //});
            setState(() => _selectedCats = val);
          }),
    )

For more example refer to the chips_choice package examples.

Hope this will help.