I have a Google maps API where in i was trying to save the place key and the JSON response of that particular place in the SQFLite. I was able to write the fromJSON method but how to write the toMap method?

This is the model without the toMap method

class GeometryModel {
  final LocationModel locationModel;

  GeometryModel({required this.locationModel});

  factory GeometryModel.fromJson(Map<dynamic, dynamic> parsedJson) {
    return GeometryModel(locationModel: LocationModel.fromJson(parsedJson['location']));
  }
}

class LocationModel {
  final double latitude;
  final double longitude;

  LocationModel({required this.latitude, required this.longitude});

  factory LocationModel.fromJson(Map<dynamic, dynamic> parsedJson) {
    return LocationModel(latitude: parsedJson['lat'], longitude: parsedJson['lng']);
  }
}

class PlaceModel {
  final String placeId;
  final GeometryModel geometryModel;
  final String address;
  final String name;

  PlaceModel({required this.placeId, required this.geometryModel, required this.address, required this.name});

  factory PlaceModel.fromJson(Map<String, dynamic> parsedJson) {
    return PlaceModel(
        placeId: parsedJson['place_id'],
        name: parsedJson['vicinity'],
        geometryModel: GeometryModel.fromJson(parsedJson['geometry']),
        address: parsedJson['formatted_address'],
    );
  }
}

This is the response I'm receiving from the server

{
    "html_attributions": [],
    "result": {
        "formatted_address": "New York, NY, USA",
        "geometry": {
            "location": {
                "lat": 40.7127753,
                "lng": -74.0059728
            },
            "viewport": {
                "northeast": {
                    "lat": 40.91757705070789,
                    "lng": -73.70027206817629
                },
                "southwest": {
                    "lat": 40.47739906045452,
                    "lng": -74.25908991427882
                }
            }
        },
        "icon_background_color": "#7B9EB0",
        "icon_mask_base_uri":  "https://maps.gstatic.com/mapfiles/place_api/icons/v2/generic_pinlet",
        "name": "New York"
        "url": "https://maps.google.com/?q=New York, NY, USA&ftid=0x89c24fa5d33f083b:0xc80b8f06e177fe62",
        "utc_offset": -240,
        "vicinity": "New York","
    },
    "status": "OK"
}

CodePudding user response：

Here is the example of Viewport, how to convert toJson/toMap and use this link to help you to convert your JSON to map

class Viewport {
  Viewport viewport;

  Viewport({this.viewport});

  Viewport.fromJson(Map<String, dynamic> json) {
    viewport = json['viewport'] != null
        ? new Viewport.fromJson(json['viewport'])
        : null;
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    if (this.viewport != null) {
      data['viewport'] = this.viewport.toJson();
    }
    return data;
  }
}

class Viewport {
  Northeast northeast;
  Northeast southwest;

  Viewport({this.northeast, this.southwest});

  Viewport.fromJson(Map<String, dynamic> json) {
    northeast = json['northeast'] != null
        ? new Northeast.fromJson(json['northeast'])
        : null;
    southwest = json['southwest'] != null
        ? new Northeast.fromJson(json['southwest'])
        : null;
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    if (this.northeast != null) {
      data['northeast'] = this.northeast.toJson();
    }
    if (this.southwest != null) {
      data['southwest'] = this.southwest.toJson();
    }
    return data;
  }
}

class Northeast {
  double lat;
  double lng;

  Northeast({this.lat, this.lng});

  Northeast.fromJson(Map<String, dynamic> json) {
    lat = json['lat'];
    lng = json['lng'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['lat'] = this.lat;
    data['lng'] = this.lng;
    return data;
  }
}

CodePudding user response：

You can achieve it like this :

  Map<String, dynamic> toMap() {
var map = Map<String, dynamic>();
map['place_id'] = placeId;
map['address'] = address;
map['name'] = name;
map['geometry_model_id']=geometryModel.id; //saves id
return map;}

CodePudding user response：

Use JsonToDart website. You just need to paste your JSON data and it will convert json data to model class along with fromJson() and toJson() or toMap().

NOTE: If you get json syntax error you need to verify your json data is Valid or not. For json validation check json_parser_online website.

CodePudding user response：

There's another option to work with JSON data and without creating models and without using generators! How? Using the g-json package.

See my answer to another question (How to parse complex JSON using default methods in Flutter?) that can help you, Naan Avan.