I am trying to assign JSON response dart Entity using fromJson but the return object is having all null values.
The json looks like below:
{
"doc":{
"id":"6496772",
"name":"Test Document",
}
"custom_keys":[
{
"key": "X1",
"name":"X1"
},
{
"key": "X2",
"name":"X2"
},
]
}
I have created Test Entity as below
class Test{
final String id;
final String name;
const Feature({
this.id,
this.name,
});
Feature.fromMap(Map<String, dynamic> map) :
id= map['id'],
name= map['name'];
}
API method:
var request = await httpClient.getUrl(Uri.parse(url));
var response = await request.close();
if (response.statusCode == HttpStatus.OK) {
var json = await response.transform(UTF8.decoder).join();
print(json.toString());
var data = JSON.decode(json);
return new Test.fromMap(data['doc']);
// getting null object from above return statement
There is error message. what could be the issue ?
the null object probably comes from id= map['id'], while your json only returns "key" and "name".
you have to map each json element to a property. changing the constructor to
Feature.fromMap(Map<String, dynamic> map) :
id= map['key'],
name= map['name'];
will probably do the trick.
Related
Good afternoon, I may have found a small error, but I can't figure it out until now..
I have the following class in dart, the purpose of this class is to receive json and transform each field to object
class Attributes {
final String lpn; //itemId
final String type; //itemType (REEL,FEEDER,ETC)
final String feederContainer; //containerId
final String feederSide; //locationInContainer(A o B)
final String locationInTool; //locationInTool
Attributes(
{required this.lpn,
required this.type,
required this.feederContainer,
required this.feederSide,
required this.locationInTool});
factory Attributes.fromJson(Map json) {
return Attributes(
lpn: json['itemId'],
type: json['itemType'],
feederContainer: json['containerId'],
feederSide: json['locationInContainer'],
locationInTool: json['locationInTool'],
);
}
}
class PartNumberAt {
final String partNumber; //partNumber
final String quantity; //quantity
final String initialQuantity; //initialQuantity
PartNumberAt(
{required this.partNumber,
required this.quantity,
required this.initialQuantity});
factory PartNumberAt.fromJson(Map json) {
return PartNumberAt(
partNumber: json['partNumber'],
quantity: json['quantity'],
initialQuantity: json['initialQuantity'],
);
}
}
//partnumber RawMaterial
class ReelPartNumber {
final PartNumberAt partNumberAt;
ReelPartNumber({required this.partNumberAt});
factory ReelPartNumber.fromJson(Map json) {
return ReelPartNumber(
partNumberAt: PartNumberAt.fromJson(json['attributes']),
);
}
}
class ReelLpn {
Attributes? attributes;
ReelPartNumber? reelPartNumber;
ReelLpn(
{required Attributes attributes, required ReelPartNumber reelPartNumber});
factory ReelLpn.fromJson(Map json) {
return ReelLpn(
attributes: Attributes.fromJson(json['attributes']),
reelPartNumber: ReelPartNumber.fromJson(json['RawMaterial']),
);
}
}
and I have a file where I make http requests, the request returns the following
{
"attributes": {
"itemId": "0605007783",
"itemKey": "14992663",
"itemType": "REEL",
"itemTypeClass": "Component Lot",
"containerId": "FA0210AEF424292",
"locationInContainer": "B",
"toolContainerId": "SMT6",
"locationInTool": "10004-B",
"quarantineLocked": "false",
"expired": "false",
"initTmst": "2022-01-20T09:40:30.969-03:00"
},
"RawMaterial": {
"attributes": {
"partNumber": "11201312001166",
"partNumberDesc": "",
"supplierId": "DEFAULT",
"quantity": "2497.0",
"initialQuantity": "5000.0",
"rejectedQuantity": "3.0",
"manualAdjustmentQuantity": "548.0"
},
}
and the request is made as follows
Future<ReelLpn?> getReelData(String lpn) async {
http.Response response = await http.get(Uri.parse(apiUrl+'/$lpn'));
if (response.statusCode == 200) {
Map data = (json.decode(response.body)); //conver to json
print(data);
ReelLpn reelLpn = ReelLpn.fromJson(data); //transform json to ReelLpn
return reelLpn;
}
return null;
}
and I call the service as follows
ReelLpn? data = await CogiscanService().getReelData('0605007783');
print(data?.attributes?.type);
my problem starts there, when I print
print(data?.attributes?.type);
it returns null, I put several prints, in the ReelL class, Attributes and PartNumber, to see if I was reading the Map correctly, and they definitely read correctly.
So why when I want to access any of the fields does it return null?
Change your ReelLpn Constructor. you are not referencing the class members... thats why its always null.
ReelLpn({required this.attributes, required this.reelPartNumber});
I am beginner in flutter. Please help me get and set below json data into model in flutter. I am using POST method.
'''
{
"success": 1,
"data": {
"user_id": 2,
"email": "ajay.singhal#ollosoft1.com",
"phone": "9414905280",
"password": "1436a615e62482ba4f075c1d4a4fd94b",
"account_status": "Active",
"date_of_birth": "1953-09-07T00:00:00.000Z",
"address": "Jaipur Rajasthan",
"profile_url": "http://18.217.236.99:4200/assets/profile_img/2/RBI-keeps-policy-rate-unchanged-1.jpg",
"first_name": "Ajay",
"last_name": "singhal"
}
}
'''
Below is my Model class named UserInfoModel
import 'UserInfoDataModel.dart';
class UserInfoModel {
final int success;
final UserInfoDataModel data;
UserInfoModel(this.success, this.data);
factory UserInfoModel.fromJson(dynamic json) {
if (json['data'] != null) {
var tagObjsJson = json['data'];
UserInfoDataModel _tags =
tagObjsJson.map((tagJson) => UserInfoDataModel.fromJson(tagJson));
return UserInfoModel(json['success'] as int, _tags);
}
}
#override
String toString() {
return '{${this.success}, ${this.data}}';
}
}
Below is submodel name is UserInfoDataModel
import 'package:flutter/material.dart';
class UserInfoDataModel {
int user_id;
String email;
String phone;
String password;
String account_status;
String date_of_birth;
String address;
String profile_url;
String first_name;
String last_name;
UserInfoDataModel(
{this.user_id,
this.email,
this.phone,
this.password,
this.account_status,
this.date_of_birth,
this.address,
this.profile_url,
this.first_name,
this.last_name});
factory UserInfoDataModel.fromJson(Map<String, dynamic> json) {
return UserInfoDataModel(
user_id: json['user_id'] as int,
email: json['email'],
phone: json['phone'],
password: json['password'],
account_status: json['account_status'],
date_of_birth: json['date_of_birth'],
address: json['address'],
profile_url: json['profile_url'],
first_name: json['first_name'],
last_name: json['last_name'],
);
}
}
My APi Call is below Using POST Method
I am successfully getting response, but unable to set in model
UserInfoModel _userInfoModel;
UserInfoDataModel _userInfoDataModel;
String url = BaseURLHeaders().getBaseURl() + "userInfo";
Map headers = BaseURLHeaders().getHeader();
#override
void initState() {
// TODO: implement initState
super.initState();
getData();
}
Future<UserInfoModel> getData() async {
String user_id = "1";
var mapData = new Map<String, dynamic>();
mapData['user_id'] = user_id;
// mapData['first_name'] = firstName;
var response = await http.post(
url,
headers: headers,
body: mapData,
);
setState(() {
print("userInfoDetails: ${response.body}");
print("urlTop: ${url}");
print("headersTop: ${headers}");
print("responseCode: ${response.statusCode}");
});
if (response.statusCode == 200) {
var res = json.decode(response.body);
_userInfoModel = UserInfoModel.fromJson(res);
if (_userInfoModel.success == 1) {
var data = res["data"];
setState(() {
print("responseBody: ${res}");
print("userInfoSuccess: ${_userInfoModel.success}");
print("dataVaalue: ${data["email"]}");
print("urlBelow: ${url}");
print("headersBelow: ${headers}");
});
}
}
}
UserInfoDataModel _tags =
tagObjsJson.map((tagJson) => UserInfoDataModel.fromJson(tagJson));
here you are actually treated tagObjsJson as a list. but it is a JsonObject so there you don't want the map function.
you can access the object as
UserInfoDataModel _tags =UserInfoDataModel.fromJson(tagJson);
You can use json_serializer in flutter. See flutter docs.
If you use IntelliJ IDEA, you can use DartToJson package. It generates automatically for you and you can use fromJson and toJson method.
Can anyone tell me how to parse arrays of object in flutter. When I am parsing the json I am getting error as List is not a subtype of type Map<String, dynamic>.
Below is my json file which needs to be parsed. Please help me to fix this issue.
[
{
"empPayslipsId": "2021012000440",
"month": "Jan",
"description": "Payslip for JAN 2021 (Month End)",
"paymentPeriod": "1/1/2021 12:00:00 AM - 1/31/2021 12:00:00 AM",
"lastAccessBy": "0002\r\n118.200.199.70",
"lastAccessDate": "20210202",
"lastAccessTime": "105706",
"successAccess": "2",
"failAccess": "2"
}
]
Future<void> loadQueryPeriod(int year, var month) async {
String baseURL = '${domainURL}api/PaySlip?year=$year&month=$month';
try {
final response = await http.get(baseURL, headers: {
'Content-Type': 'application/json',
'Accept': 'application/json',
'Authorization':
'Bearer ${Provider.of<UserVM>(navigatorKey.currentContext, listen: false).accessToken}',
});
print('UIC PDF response : ${response.body}');
print(
'UIC Token response : ${Provider.of<UserVM>(navigatorKey.currentContext, listen: false).accessToken}');
if (response.statusCode == 200) {
final Map<String, dynamic> data = json.decode(response.body);
print('result type: ${data.runtimeType}');
}
} catch (e) {
print(e);
throw Exception('Download PDF Fail! ${e.toString()}');
}
}
}
Change it to this:
final Map<String, dynamic> data = json.decode(response.body)[0];
This is because your map is inside a list. Look at the square brackets [ ] enclosing your map. The map that you need, is at index[0] of this list.
use this podo class :
// Generated by https://quicktype.io
// To parse this JSON data, do
//
// final sample = sampleFromJson(jsonString);
import 'dart:convert';
List<Sample> sampleFromJson(String str) {
final jsonData = json.decode(str);
return new List<Sample>.from(jsonData.map((x) => Sample.fromJson(x)));
}
String sampleToJson(List<Sample> data) {
final dyn = new List<dynamic>.from(data.map((x) => x.toJson()));
return json.encode(dyn);
}
class Sample {
String empPayslipsId;
String month;
String description;
String paymentPeriod;
String lastAccessBy;
String lastAccessDate;
String lastAccessTime;
String successAccess;
String failAccess;
Sample({
this.empPayslipsId,
this.month,
this.description,
this.paymentPeriod,
this.lastAccessBy,
this.lastAccessDate,
this.lastAccessTime,
this.successAccess,
this.failAccess,
});
factory Sample.fromJson(Map<String, dynamic> json) => new Sample(
empPayslipsId: json["empPayslipsId"],
month: json["month"],
description: json["description"],
paymentPeriod: json["paymentPeriod"],
lastAccessBy: json["lastAccessBy"],
lastAccessDate: json["lastAccessDate"],
lastAccessTime: json["lastAccessTime"],
successAccess: json["successAccess"],
failAccess: json["failAccess"],
);
Map<String, dynamic> toJson() => {
"empPayslipsId": empPayslipsId,
"month": month,
"description": description,
"paymentPeriod": paymentPeriod,
"lastAccessBy": lastAccessBy,
"lastAccessDate": lastAccessDate,
"lastAccessTime": lastAccessTime,
"successAccess": successAccess,
"failAccess": failAccess,
};
}
Now inorder to parse json call,
Sample sample = sampleFromJson(jsonString);
via this you will get the access to sample PODO class and you can access any object you want.
The initial data you received by calling a get request isn't stored in a map, but rather in a list.
You should do something like this to receive your initial data.
if (response.statusCode == 200) {
final List<dynamic> data = json.decode(response.body);
}
From there, they're numerous ways to get the data from your data variable. You can use lists here if you want, for example to get the value of month in the JSON.
final String month = data[0]['month'];
If you'd prefer to use Maps, the syntax it'll look like this
final Map<String, dynamic> endpointData = data[0];
final String responseKey = 'month';
final var result = endpointData[responseKey];
if you have data model you can do it like this
fromJsonList(List<dynamic> jsonList) {
List<YourModel> yourModelList = [];
jsonList.forEach((jsonModel) {
menuModelsOfferList.add(YourModel.fromJson(jsonModel));
});
I have objects that will filled by a user in a form. I parse these objects to json and add that json in a list to pass in body of request. But i cant do this.
incrementListPaymentSlipes(PaymentSlipes objPayment) async {
objPayment.name = "Douglas";
objPayment.personalId = "00000000000";
Map<String, dynamic> json = objPayment.toJson();
listPaymentSlipes.add(jsonEncode(json));
}
var response = await http.post(url, body: {
"payment_slips": listPaymentSlipes,
}
example of correct body:
"payment_slips": [
{
"personal_id": "01888728680",
"name": "Fulano da Silva"
}
]
{"error":"'{{personal_id: 00000000000, name: Douglas}}' é invalido como 'payment_slips'","code":"payment_slips_invalid"}```
You can do it in a very simple way. Create payment.dart file and copy paste the below code classes.
class PaymentList {
PaymentList(this.payments);
List<Payment> payments;
Map<String, dynamic> toJson() => <String, dynamic>{
'payment_slips': payments,
};
}
class Payment {
Payment({this.name, this.personalId});
String name;
String personalId;
Map<String, dynamic> toJson() => <String, dynamic>{
'personal_id': personalId,
'name': name,
};
}
Now you can covert it to the required json format using below code. For example I am creating a dummy list:
final PaymentList paymentList =
PaymentList(List<Payment>.generate(2, (int index) {
return Payment(name: 'Person $index', personalId: '$index');
}));
final String requestBody = json.encoder.convert(paymentList);
The requestBody variable will have the json string as follows:
{"payment_slips": [
{
"personal_id": "0",
"name": "Person 0"
},
{
"personal_id": "1",
"name": "Person 1"
}
]}
Now you can call the api:
var response = await http.post(url, body: requestBody}
Note: Please import the below package, which will be required to access json:
import 'dart:convert';
So it looks like you are not getting the JSON you expect. I have put together some code to show you how to get the body you want.
Link to run in DartPad https://dartpad.dartlang.org/3fde03078e56efe13d31482dea8e5eef
class PaymentSlipes {
String name;
String personaId;
ObjPayment({this.name, this.personaId});
//You create this to convert your object to JSON
Map<String, dynamic> toJson() => {'name': name, 'personaId': personaId};
}
// This method is needed to convert the list of ObjPayment into an Json Array
List encondeToJson(List<PaymentSlipes> list) {
List jsonList = List();
list.map((item) => jsonList.add(item.toJson())).toList();
return jsonList;
}
// This is an example and this code will run in DartPad link above
void main() {
PaymentSlipes objPayment = PaymentSlipes(name: "Douglas", personaId: "123425465");
PaymentSlipes objPayment2 = PaymentSlipes(name: "Dave", personaId: "123425465;
PaymentSlipes objPayment3 = PaymentSlipes(name: "Mike", personaId: "123425465");
var list = [objPayment, objPayment2, objPayment3];
// This is the mapping of the list under the key payment_slips as per your example and the body i would pass to the POST
var finalJson = {"payment_slips": encondeToJson(list)};
print(finalJson);
}
i have class that generate json list this is my class
class Tool{
String Name;
bool selection;
String englishName;
Map<String, dynamic> toJson() {
return {
'Name': persianName,
'selection': selection,
'englishName': englishName
};
}
}
List<Tool> tools=new List();
setTool(tool){
tools.add(tool);
}
toolsLength(){
return tools.length;
}
updatetool(index,goal){
tools[index]=goal;
}
getTool(index){
return tools[index];
}
getAllTools(){
return tools;
}
and this is dio library that send my list to server every thing is ok but my array is into Double quotation in other word my list is string how to pick up double quotation around of json array . if assume my json array hase
"tools": [{"name":"jack","selection" : false " ,"englishName":"jock"}]
result is :
"tools": "[{"name":"jack","selection" : false " ,"englishName":"jock"}]"
how fix it this is my class for send
FormData formData = new FormData.from({
"tools":jsonEncode(getAllTools().map((e) => e.toJson()).toList()) ,
});
response = await
dio.post("${strings.baseurl}/analyze/$username/$teacher", data:
formData);
print("----------> response is :"+response.toString());
Edit
You can paste the following code to DarPad https://dartpad.dartlang.org/
The following demo shows transform your Json String to Tool List and Convert your Tool List to JSON string again and use map.toJson
var yourresult = toolList.map((e) => e.toJson()).toList();
you can see result in picture
use FormData.from need to know what your api's correct JSON String.
Please test your web api with Postman, if you success, you will know correct format string.
In your code
FormData formData = new FormData.from({
"tools":jsonEncode(getAllTools().map((e) => e.toJson()).toList()) ,
});
if you are trying to to do
FormData formData = new FormData.from({
"tools":'[{"name":"jack","selection" : false ,"englishName":"jock"}, {"name":"jack2","selection" : false ,"englishName":"jock2"}]' ,
});
so you can get your json string first and put it in FormData
var toolsJson = toolsToJson(toolList);
FormData formData = new FormData.from({
"tools":toolsJson ,
});
full demo code, you can paste to DartPad to see string and list conversion
import 'dart:async';
import 'dart:io';
import 'dart:core';
import 'dart:convert';
class Tools {
String name;
bool selection;
String englishName;
Tools({
this.name,
this.selection,
this.englishName,
});
factory Tools.fromJson(Map<String, dynamic> json) => new Tools(
name: json["name"],
selection: json["selection"],
englishName: json["englishName"],
);
Map<String, dynamic> toJson() => {
"name": name,
"selection": selection,
"englishName": englishName,
};
}
main() {
List<Tools> toolsFromJson(String str) => new List<Tools>.from(json.decode(str).map((x) => Tools.fromJson(x)));
String toolsToJson(List<Tools> data) => json.encode(new List<dynamic>.from(data.map((x) => x.toJson())));
var toolsStr = '[{"name":"jack","selection" : false ,"englishName":"jock"}, {"name":"jack2","selection" : false ,"englishName":"jock2"}]';
var toolList = toolsFromJson(toolsStr);
var toolsJson = toolsToJson(toolList);
print("toolsJson ${toolsJson} \n");
var toolsmap = toolList[0].toJson();
print("toolsmap ${toolsmap.toString()}\n");
var yourresult = toolList.map((e) => e.toJson()).toList();
print(yourresult.toString());
}
you can paste your JSON string to https://app.quicktype.io/, you will get correct Dart class
correct JSON string of your sample. in false keyword followed by a " cause JSON string parsing error.
[
{"name":"jack",
"selection" : false ,
"englishName":"jock"
}
]
code to parse JSON string and encode to List, use toJson will convert to JSON string you need to send with dio form
// To parse this JSON data, do
//
// final tools = toolsFromJson(jsonString);
import 'dart:convert';
List<Tools> toolsFromJson(String str) => new List<Tools>.from(json.decode(str).map((x) => Tools.fromJson(x)));
String toolsToJson(List<Tools> data) => json.encode(new List<dynamic>.from(data.map((x) => x.toJson())));
class Tools {
String name;
bool selection;
String englishName;
Tools({
this.name,
this.selection,
this.englishName,
});
factory Tools.fromJson(Map<String, dynamic> json) => new Tools(
name: json["name"],
selection: json["selection"],
englishName: json["englishName"],
);
Map<String, dynamic> toJson() => {
"name": name,
"selection": selection,
"englishName": englishName,
};
}