Not properly mapping values in Dart model - flutter

Question

I know I am not properly mapping values when it comes to make a GET request since I am getting a null response.
Specifically I know the problem it is the fields "Behavior" and "Description" since they are lists and are more complex to map for me. Before adding these two fields the mapping was done properly and I was able to get the proper response.
my fetchdata function:
fetchData(url) async {
var client = http.Client();
final response = await client.get(Uri.parse(url));
if (response.statusCode == 200) {
var jsonDecoded = json.decode(response.body);
BreedList = jsonDecoded.map((data) => DogClass.fromJson(data)).toList();
return jsonDecoded;
} else {
throw Exception('Failed to load data');
}
}
Here I am attaching my data model.
class DogClass {
Id? _iId;
String? _breed;
String? _origin;
String? _url;
String? _img;
List<Behavior>? _behavior;
List<Description>? _description;
final _descriptionlist = <Description>[];
DogClass(
{Id? iId,
String? breed,
String? origin,
String? url,
String? img,
List<Behavior>? behavior,
List<Description>? description}) {
if (iId != null) {
this._iId = iId;
}
if (breed != null) {
this._breed = breed;
}
if (origin != null) {
this._origin = origin;
}
if (url != null) {
this._url = url;
}
if (img != null) {
this._img = img;
}
if (behavior != null) {
this._behavior = behavior;
}
if (description != null) {
this._description = description;
}
}
Id? get iId => _iId;
set iId(Id? iId) => _iId = iId;
String? get breed => _breed;
set breed(String? breed) => _breed = breed;
String? get origin => _origin;
set origin(String? origin) => _origin = origin;
String? get url => _url;
set url(String? url) => _url = url;
String? get img => _img;
set img(String? img) => _img = img;
List<Behavior>? get behavior => _behavior;
set behavior(List<Behavior>? behavior) => _behavior = behavior;
List<Description>? get description => _description;
set description(List<Description>? description) => _description = description;
factory DogClass.fromJson(Map<String, dynamic> json) {
return DogClass(
iId: json['_id'] != null ? Id.fromJson(json['_id']) : null,
breed: json['breed'],
origin: json['origin'],
url: json['url'],
img: json['img'],
behavior: (json['behavior'] as List).cast<Behavior>(),
description: (json['Description'] as List).cast<Description>());
}
}
class Id {
String? _oid;
Id({String? oid}) {
if (oid != null) {
this._oid = oid;
}
}
String? get oid => _oid;
set oid(String? oid) => _oid = oid;
Id.fromJson(Map<String, dynamic> json) {
_oid = json['$oid'];
}
}
class Behavior {
Id? _iId;
String? _imageLink;
int? _goodWithChildren;
int? _goodWithOtherDogs;
int? _shedding;
int? _grooming;
int? _drooling;
int? _coatLength;
int? _goodWithStrangers;
int? _playfulness;
int? _protectiveness;
int? _trainability;
int? _energy;
int? _barking;
int? _minLifeExpectancy;
int? _maxLifeExpectancy;
double? _maxHeightMale;
double? _maxHeightFemale;
int? _maxWeightMale;
int? _maxWeightFemale;
int? _minHeightMale;
int? _minHeightFemale;
int? _minWeightMale;
int? _minWeightFemale;
String? _breed;
Behavior(
{Id? iId,
String? imageLink,
int? goodWithChildren,
int? goodWithOtherDogs,
int? shedding,
int? grooming,
int? drooling,
int? coatLength,
int? goodWithStrangers,
int? playfulness,
int? protectiveness,
int? trainability,
int? energy,
int? barking,
int? minLifeExpectancy,
int? maxLifeExpectancy,
double? maxHeightMale,
double? maxHeightFemale,
int? maxWeightMale,
int? maxWeightFemale,
int? minHeightMale,
int? minHeightFemale,
int? minWeightMale,
int? minWeightFemale,
String? breed}) {
if (iId != null) {
this._iId = iId;
}
if (imageLink != null) {
this._imageLink = imageLink;
}
if (goodWithChildren != null) {
this._goodWithChildren = goodWithChildren;
}
if (goodWithOtherDogs != null) {
this._goodWithOtherDogs = goodWithOtherDogs;
}
if (shedding != null) {
this._shedding = shedding;
}
if (grooming != null) {
this._grooming = grooming;
}
if (drooling != null) {
this._drooling = drooling;
}
if (coatLength != null) {
this._coatLength = coatLength;
}
if (goodWithStrangers != null) {
this._goodWithStrangers = goodWithStrangers;
}
if (playfulness != null) {
this._playfulness = playfulness;
}
if (protectiveness != null) {
this._protectiveness = protectiveness;
}
if (trainability != null) {
this._trainability = trainability;
}
if (energy != null) {
this._energy = energy;
}
if (barking != null) {
this._barking = barking;
}
if (minLifeExpectancy != null) {
this._minLifeExpectancy = minLifeExpectancy;
}
if (maxLifeExpectancy != null) {
this._maxLifeExpectancy = maxLifeExpectancy;
}
if (maxHeightMale != null) {
this._maxHeightMale = maxHeightMale;
}
if (maxHeightFemale != null) {
this._maxHeightFemale = maxHeightFemale;
}
if (maxWeightMale != null) {
this._maxWeightMale = maxWeightMale;
}
if (maxWeightFemale != null) {
this._maxWeightFemale = maxWeightFemale;
}
if (minHeightMale != null) {
this._minHeightMale = minHeightMale;
}
if (minHeightFemale != null) {
this._minHeightFemale = minHeightFemale;
}
if (minWeightMale != null) {
this._minWeightMale = minWeightMale;
}
if (minWeightFemale != null) {
this._minWeightFemale = minWeightFemale;
}
if (breed != null) {
this._breed = breed;
}
}
Id? get iId => _iId;
set iId(Id? iId) => _iId = iId;
String? get imageLink => _imageLink;
set imageLink(String? imageLink) => _imageLink = imageLink;
int? get goodWithChildren => _goodWithChildren;
set goodWithChildren(int? goodWithChildren) =>
_goodWithChildren = goodWithChildren;
int? get goodWithOtherDogs => _goodWithOtherDogs;
set goodWithOtherDogs(int? goodWithOtherDogs) =>
_goodWithOtherDogs = goodWithOtherDogs;
int? get shedding => _shedding;
set shedding(int? shedding) => _shedding = shedding;
int? get grooming => _grooming;
set grooming(int? grooming) => _grooming = grooming;
int? get drooling => _drooling;
set drooling(int? drooling) => _drooling = drooling;
int? get coatLength => _coatLength;
set coatLength(int? coatLength) => _coatLength = coatLength;
int? get goodWithStrangers => _goodWithStrangers;
set goodWithStrangers(int? goodWithStrangers) =>
_goodWithStrangers = goodWithStrangers;
int? get playfulness => _playfulness;
set playfulness(int? playfulness) => _playfulness = playfulness;
int? get protectiveness => _protectiveness;
set protectiveness(int? protectiveness) => _protectiveness = protectiveness;
int? get trainability => _trainability;
set trainability(int? trainability) => _trainability = trainability;
int? get energy => _energy;
set energy(int? energy) => _energy = energy;
int? get barking => _barking;
set barking(int? barking) => _barking = barking;
int? get minLifeExpectancy => _minLifeExpectancy;
set minLifeExpectancy(int? minLifeExpectancy) =>
_minLifeExpectancy = minLifeExpectancy;
int? get maxLifeExpectancy => _maxLifeExpectancy;
set maxLifeExpectancy(int? maxLifeExpectancy) =>
_maxLifeExpectancy = maxLifeExpectancy;
double? get maxHeightMale => _maxHeightMale;
set maxHeightMale(double? maxHeightMale) => _maxHeightMale = maxHeightMale;
double? get maxHeightFemale => _maxHeightFemale;
set maxHeightFemale(double? maxHeightFemale) =>
_maxHeightFemale = maxHeightFemale;
int? get maxWeightMale => _maxWeightMale;
set maxWeightMale(int? maxWeightMale) => _maxWeightMale = maxWeightMale;
int? get maxWeightFemale => _maxWeightFemale;
set maxWeightFemale(int? maxWeightFemale) =>
_maxWeightFemale = maxWeightFemale;
int? get minHeightMale => _minHeightMale;
set minHeightMale(int? minHeightMale) => _minHeightMale = minHeightMale;
int? get minHeightFemale => _minHeightFemale;
set minHeightFemale(int? minHeightFemale) =>
_minHeightFemale = minHeightFemale;
int? get minWeightMale => _minWeightMale;
set minWeightMale(int? minWeightMale) => _minWeightMale = minWeightMale;
int? get minWeightFemale => _minWeightFemale;
set minWeightFemale(int? minWeightFemale) =>
_minWeightFemale = minWeightFemale;
String? get breed => _breed;
set breed(String? breed) => _breed = breed;
factory Behavior.fromJson(Map<String, dynamic> json) {
return Behavior(
iId : json['_id'] != null ? Id.fromJson(json['_id']) : null,
imageLink : json['image_link'],
goodWithChildren : json['good_with_children'],
goodWithOtherDogs : json['good_with_other_dogs'],
shedding : json['shedding'],
grooming : json['grooming'],
drooling : json['drooling'],
coatLength : json['coat_length'],
goodWithStrangers : json['good_with_strangers'],
playfulness : json['playfulness'],
protectiveness : json['protectiveness'],
trainability : json['trainability'],
energy : json['energy'],
barking : json['barking'],
minLifeExpectancy : json['min_life_expectancy'],
maxLifeExpectancy : json['max_life_expectancy'],
maxHeightMale : json['max_height_male'],
maxHeightFemale : json['max_height_female'],
maxWeightMale : json['max_weight_male'],
maxWeightFemale : json['max_weight_female'],
minHeightMale : json['min_height_male'],
minHeightFemale : json['min_height_female'],
minWeightMale : json['min_weight_male'],
minWeightFemale : json['min_weight_female'],
breed : json['breed']
);}
}
class Description {
Id? iId;
String? breed;
String? contenido;
Description({this.iId, this.breed, this.contenido});
factory Description.fromJson(Map<String, dynamic> json) {
return Description(
iId: json['_id'] != null ? Id.fromJson(json['_id']) : null,
breed: json['breed'],
contenido: json['contenido'],
);
}
}
Here's is my json content:
[{"_id": {"$oid": "625f2900fe6aeb351381c3f5"}, "breed": "Africanis", "origin": "Southern Africa", "url": "https://en.wikipedia.org/wiki/Af", "img": "https://upload.wikimedia.org/wikipedia/commons/thumb/4/", "behavior": [], "Description": [{"_id": {"$oid": "626829de7103fd0096bd5dd8"}, "breed": "Africanis", "contenido": "Some content"}]}
Any help would be really appreciated.

Answer 1

I prefer you to use a vs code tool to easily make a dart data model
Name: Json to Dart Model
VS Marketplace Link:
https://marketplace.visualstudio.com/items?itemName=hirantha.json-to-dart
Here is the model code, You just pass GET response data through it
class DogClass {
Id? id;
String? breed;
String? origin;
String? url;
String? img;
List<dynamic>? behavior;
List<Description>? description;
DogClass({
this.id,
this.breed,
this.origin,
this.url,
this.img,
this.behavior,
this.description,
});
factory DogClass.fromMap(Map<String, dynamic> data) => DogClass(
id: data['_id'] == null
? null
: Id.fromMap(data['_id'] as Map<String, dynamic>),
breed: data['breed'] as String?,
origin: data['origin'] as String?,
url: data['url'] as String?,
img: data['img'] as String?,
behavior: data['behavior'] as List<dynamic>?,
description: (data['Description'] as List<dynamic>?)
?.map((e) => Description.fromMap(e as Map<String, dynamic>))
.toList(),
);
}
/// id DogClass class
///
class Id {
String? oid;
Id({this.oid});
factory Id.fromMap(Map<String, dynamic> data) => Id(
oid: data['\$oid'] as String?,
);
}
// description class DogClass
//
class Description {
Id? id;
String? breed;
String? contenido;
Description({this.id, this.breed, this.contenido});
factory Description.fromMap(Map<String, dynamic> data) => Description(
id: data['_id'] == null
? null
: Id.fromMap(data['_id'] as Map<String, dynamic>),
breed: data['breed'] as String?,
contenido: data['contenido'] as String?,
);
}