CODEWITHSUNDEEP
flutterflutter-http
Ankit Shah
Ankit Shah

Reputation: 1335

List<dynamic>' is not a subtype of type 'Map<dynamic, dynamic>. Flutter issue when parsing api response to model

I am trying to hit an API and then store it into the model? The API response is quite lengthy and consists of multiple level key-value pairs. The API I am hitting is https://gharsansar-backend.herokuapp.com/listing/get/all. This returns a list of some properties from the database. The Model I made for in the Flutter is:

class Listing {
  Map property;
  Map listedby;
  int listPrice;
  int featured;
  String status;
  String id;
  String listType;
  String listingTitle;
  String listingSlug;
  String contactNumber;
  String specialNote;
  String listPriceUnit;
  String numOfViewers;
  Map viewers;
  Map favouriteOf;

  Listing();

  Listing.fromJSON(Map<String, dynamic> jsonMap) {
    print(jsonMap);
    try {
      property = jsonMap['property'] != null ? jsonMap['property'] : '';
      listedby = jsonMap['listedby'] != null ? jsonMap['listedby'] : '';
      id = jsonMap['_id'] != null ? jsonMap['_id'] : '';
      listPrice = jsonMap['listPrice'] != null ? jsonMap['listPrice'] : '';
      listType = jsonMap['listType'] != null ? jsonMap['listType'] : '';
      featured = jsonMap['featured'] != null ? jsonMap['featured'] : '';
      favouriteOf =
          jsonMap['favouriteOf'] != null ? jsonMap['favouriteOf'] : '';
      viewers = jsonMap['viewers'] != null ? jsonMap['viewers'] : '';
      listingTitle =
          jsonMap['listingTitle'] != null ? jsonMap['listingTitle'] : '';
      listingSlug =
          jsonMap['listingSlug'] != null ? jsonMap['listingSlug'] : '';
      status = jsonMap['status'] != null ? jsonMap['status'] : '';

      contactNumber =
          jsonMap['contactNumber'] != null ? jsonMap['contactNumber'] : '';
      specialNote =
          jsonMap['specialNote'] != null ? jsonMap['specialNote'] : '';
      listPriceUnit =
          jsonMap['listPriceUnit'] != null ? jsonMap['listPriceUnit'] : '';
      numOfViewers =
          jsonMap['numOfViewers'] != null ? jsonMap['numOfViewers'] : '';
    } catch (e) {
      print(e);
    }
  }

  Map toMap() {
    var map = new Map<String, dynamic>();
    map["property"] = property;
    map["listedby"] = listedby;
    map["_id"] = id;

    map["listPrice"] = listPrice;
    map["listType"] = listType;
    map["contactNumber"] = contactNumber;

    map["favouriteOf"] = favouriteOf;
    map["viewers"] = viewers;
    map["listingTitle"] = listingTitle;
    map["listingSlug"] = listingSlug;
    map["status"] = status;

    map["specialNote"] = specialNote;
    map["listPriceUnit"] = listPriceUnit;
    map["numOfViewers"] = numOfViewers;
    return map;
  }

  @override
  String toString() {
    var map = this.toMap();
    return map.toString();
  }
}

I am hitting the API from the flutter using the below code:

Future<Stream<Listing>> getProperties() async {
  Uri uri = Helper.getUri('listing/get/all');
  print(uri.toString());
  Map<String, dynamic> _queryParams = {};
  uri = uri.replace(queryParameters: _queryParams);
  final client = new http.Client();
  final streamedRest = await client.send(http.Request('get', uri));

  return streamedRest.stream
      .transform(utf8.decoder)
      .transform(json.decoder)
      .map((data) => Helper.getListings(data))
      .expand((data) => (data as List))
      .map((data) => Listing.fromJSON(data));
}

I am getting issue probably because of multiple elements inside the property object. I have attached a screenshot of the logs with the question. enter image description here Thanks

Upvotes: 1

Views: 60

Answers (1)

Huthaifa Muayyad
Huthaifa Muayyad

Reputation: 12363

Your Map<String,dynamic> is wrapped inside a list.

I copied this: {"success":true,"data":{"listings":[{"property":{"propertyLocation":{...etc from the response of the API you posted.

Notice,

  • "data" opens up a map which is {"listings":[{"property":{"propertyLocation"...
  • then when you access ["listings"] ==> it gives you a LIST ==> [{"property":{"propertyLocation"...
  • {"property":{"propertyLocation"... is the data you want to access, and it's currently sitting at index[0] of this parent list.

Try using

should be

map((data) => Helper.getListings(data["listings"])) to access the ["listings"] key of the map, which is the list of listings you are looking for.

instead of

map((data) => Helper.getListings(data))

Upvotes: 1

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