This is the response I am getting from server. All the properties are String and int expect data. It is a list of objects. When serializing the response it shows error. Please explain what is wrong with my code. I am from javascript background. Serialization in flutter is different from javascript.
class ResponseModel {
String image;
int row;
int column;
int position;
List<Data> data;
ResponseModel({this.image, this.row, this.column, this.position});
factory ResponseModel.fromJson(Map<String, dynamic> parsedJson) {
return ResponseModel(
image: parsedJson['image'],
row: parsedJson['row'],
column: parsedJson['column'],
position: parsedJson['position'],
);
}
}
class Data {
String imageUrl;
Data({this.imageUrl});
factory Data.fromJson(Map<String, dynamic> parsedJson) {
return Data(imageUrl: parsedJson["imageUrl"]);
}
}
[
{
"type": "image",
"row": 1,
"column": 3,
"position":"1",
"data": [
{
"imageUrl": "https://rukminim1.flixcart.com/flap/276/294/image/6dad06016c6ab319.jpg?q=90"
},
{
"imageUrl": "https://rukminim1.flixcart.com/flap/276/294/image/9ad209b0fc3d03e4.jpg?q=90"
},
{
"imageUrl": "https://rukminim1.flixcart.com/flap/276/294/image/405e10d01fae5aa5.jpg?q=90"
}
]
},
{
"type": "image",
"row": 1,
"column": 2,
"position":"3",
"data": [
{
"imageUrl": "https://rukminim1.flixcart.com/flap/414/630/image/f186565389063212.jpg?q=90"
},
{
"imageUrl": "https://rukminim1.flixcart.com/flap/414/630/image/3eda035d946b0ebf.jpg?q=90"
}
]
},
{
"type": "image",
"row": 1,
"column": 1,
"position":"2",
"data": [
{
"imageUrl": "https://rukminim1.flixcart.com/flap/1187/636/image/4436d492e2563998.jpg?q=90"
}
]
}
]
Future<dynamic> getData() async {
final response = await http.get("https://api.myjson.com/bins/1g4o04");
final parsedJson = json.decode(response.body);
final finalResponse = ResponseModel.fromJson(parsedJson);
print(finalResponse);
setState(() {
data = parsedJson;
});
}
Error image
You can use this tool and select dart Language
Its because the response is a JSON array. Which means json.decode(response.body) returns a List<dynamic> and hence the variable parsedJson is List.
You're trying to pass this List as a parameter to the ResponseModel.fromJson(Map<String, dynamic>) method which accepts a Map as the parameter.
In simple words, you're trying to pass a List where a Map is expected.
Future<dynamic> getData() async {
final response = await http.get("https://api.myjson.com/bins/1g4o04");
final parsedJson = json.decode(response.body);
List<ResponseModel> responseList = <ResponseModel>[];
parsedJson.foreach((element) {
responseList.add(ResponseModel.fromJson(element));
})
///Response list will have your data
print(responseList);
}
Your code should be something like this
Related
I am trying to parse this complex JSON data into a Flutter application. I am able to get the JSON data successfully, but not able to display the data in the application. See the code and JSON data below.
What I am doing wrong?
JSON Data
{
"response": {
"cars": [
[
{
"id": 1,
"name": "Ford Mustang GT",
"class": "Muscle Car"
},
{
"id": 2,
"name": "Dodge Challenger",
"class": "Muscle Car"
},
{
"id": 3,
"name": "Chevrolet Camaro",
"class": "Muscle Car"
},
{
"id": 4,
"name": "Pontiac Firebird",
"class": "Muscle Car"
}
]
]
}
}
Data Model
class Cars {
Cars({
this.id,
this.name,
this.carClass,
});
int id;
String name;
String carClass;
factory Cars.fromJson(Map<String, dynamic> json) => Cars(
id: json["id"],
name: json["name"],
carClass: json["class"],
);
Map<String, dynamic> toJson() => {
"id": id,
"name": name,
"class": carClass,
};
}
API Service getting the JSON Data
class ApiService {
Future<List<Cars>> getCars() async {
http.Response response = await http.get('http://localhost:3000/response');
var body;
if (response.statusCode == 200) {
body = jsonDecode(response.body);
List<dynamic> carList = body['response'];
print(body);
List<Cars> res =
carList.map((dynamic item) => Cars.fromJson(item)).toList();
return res;
}
}
}
Display Data
You can help in the construction of the classes with this application. (https://app.quicktype.io/)
These are the classes that you must use for the obtained object. Be sure to change the name of the classes that you think are relevant.
class Response {
Response({
this.response,
});
final ResponseClass response;
factory Response.fromJson(Map<String, dynamic> json) => Response(
response: ResponseClass.fromJson(json["response"]),
);
Map<String, dynamic> toJson() => {
"response": response.toJson(),
};
}
class ResponseClass {
ResponseClass({
this.cars,
});
final List<List<Car>> cars;
factory ResponseClass.fromJson(Map<String, dynamic> json) => ResponseClass(
cars: List<List<Car>>.from(json["cars"].map((x) => List<Car>.from(x.map((x) => Car.fromJson(x))))),
);
Map<String, dynamic> toJson() => {
"cars": List<dynamic>.from(cars.map((x) => List<dynamic>.from(x.map((x) => x.toJson())))),
};
}
class Car {
Car({
this.id,
this.name,
this.carClass,
});
final int id;
final String name;
final String carClass;
factory Car.fromJson(Map<String, dynamic> json) => Car(
id: json["id"],
name: json["name"],
carClass: json["class"],
);
Map<String, dynamic> toJson() => {
"id": id,
"name": name,
"class": carClass,
};
}
Finally, replace this line:
body = jsonDecode(response.body);
List<dynamic> carList = body['response'];
print(body);
List<Cars> res =
carList.map((dynamic item) => Cars.fromJson(item)).toList();
with this:
return Response.fromJson(response.body);
and replace the data type that the function returns to Response.
You can also follow the official documentation for flutter Serializtion. It's good and also saves us from the hassle of creating the conversion HashMaps.
I have two JSON data sources:
Source Data 1:
{
"result": [
{
"resource_list": "7961b907db9253045fbdf1fabf9619d4,55617907db9253045fbdf1fabf9619d2",
"project": "11216",
"project_manager": {
"value": "55617907db9253045fbdf1fabf9619d2"
}
}
]
}
Source Data 2:
{
"result": [
{
"sys_id": "7961b907db9253045fbdf1fabf9619d4",
"email": "test.user1#mysite.com"
},
{
"sys_id": "55617907db9253045fbdf1fabf9619d2",
"email": "test.user2#mysite.com"
}
]
}
I want to reference "resource_list" and "project_manager" from Source Data 1 to "sys_id" in Source Data 2 and get "email" out from Source Data 2 and then compose a final Output like below:
Output:
[
{
"__metadata":
{
"uri": "ProjectCode"
},
"externalProject": "11216",
"projectCodeAssignment":
[
{
"__metadata":
{
"uri": "projectCodeAssignment"
},
"externalProjectAssignee": "test.user1#mysite.com"
},
{
"__metadata":
{
"uri": "projectCodeAssignment"
},
"externalProjectAssignee": "test.user2#mysite.com"
}
]
}
]
Is this possible to get this done entirely in Logic App without using Function App or anything to perform it rather.
I write a js script for you. For a quick demo, I omitted some data related to __metadata, seems that is some hard code, not so important here. Try Logic below:
Code in JS code action:
var body = workflowContext.trigger.outputs.body
var data1 = body.data1;
var data2 = body.data2;
var result = [];
data1.result.forEach(item =>{
var resultItem = {};
resultItem.externalProject = item.project;
resultItem.projectCodeAssignment =[];
var resourceIds = item.resource_list.split(',');
resourceIds.forEach(id =>{
var user = data2.result.find( ({ sys_id }) => sys_id === id );
resultItem.projectCodeAssignment.push({"externalProjectAssignee": user.email})
});
result.push(resultItem);
})
return result;
Request Body(your 2 data set are named as data1 and data2 here ):
{
"data1": {
"result": [{
"resource_list": "7961b907db9253045fbdf1fabf9619d4,55617907db9253045fbdf1fabf9619d2",
"project": "11216",
"project_manager": {
"value": "55617907db9253045fbdf1fabf9619d2"
}
}
]
},
"data2": {
"result": [{
"sys_id": "7961b907db9253045fbdf1fabf9619d4",
"email": "test.user1#mysite.com"
}, {
"sys_id": "55617907db9253045fbdf1fabf9619d2",
"email": "test.user2#mysite.com"
}
]
}
}
Result:
I have an array list which needs to be converted to a single object with few of the values from array list using TypeScript in Angular 8. Below is the array:
"arrayList": [{
"name": "Testname1",
"value": "abc"
},
{
"name": "Testname2",
"value": "xyz"
}
]
This needs to be converted to the below format,
data: {
"Testname1": "abc",
"Testname2": "xyz",
}
No matter how much i try, i end up creating a list instead of a single object. Can you please help on the same?
You can use as follows,
var arr = [
{
"name": "Testname1",
"value": "abc"
},
{
"name": "Testname2",
"value": "xyz"
}
];
var result = {};
for (var i = 0; i < arr.length; i++) {
result[arr[i].name] = arr[i].value;
}
console.log(result);
Try with using .reduce() as the following:
const arrayList = [{ "name": "Testname1", "value": "abc" }, { "name": "Testname2", "value": "xyz" }];
const data = arrayList.reduce((a, {name, value}) => {
a[name] = value;
return a;
}, {});
const result = { data };
console.log(result);
Use Array.map() to get a list of [name, value] entries, then use Object.fromEntries() to convert to an object:
const arrayList = [{ "name": "Testname1", "value": "abc" }, { "name": "Testname2", "value": "xyz" }];
const result = Object.fromEntries(arrayList.map(({ name, value }) => [name, value]));
console.log(result);
Please use the below code
const rawData = {
"arrayList": [{
"name": "Testname1",
"value": "abc"
},
{
"name": "Testname2",
"value": "xyz"
}
]
};
const updatedData = {
data: {}
};
for (const item of rawData["arrayList"]) {
updatedData.data[item.name] = item.value;
}
console.log(updatedData);
My document looks like this:
{
"data": {
"eventId": "20161029125458-df-d",
"name": "first",
"purpose": "test",
"location": "yokohama",
"dateArray": [],
"attendees": [
{
"attendeeId": "2016102973634-df",
"attendeeName": "lakshman",
"personalizedDateSelection": {}
},
{
"attendeeId": "2016102973634-tyyu",
"attendeeName": "diwaakar",
"personalizedDateSelection": {}
}
]
}
}
Say, I need to update the attendee JSON array with attendeeId: 2016102973634-df. I tried many ways ways using update and condition expression, but no success.
Here is my try:
const params = {
TableName: "event",
Key: {
"eventId": eventId
},
UpdateExpression: "SET attendees[???] = ",
ConditionExpression: attendees.attendeeId = "2016102973634-df",
ExpressionAttributeValues: {
":attendee" : attendeeList
},
ReturnValues: "ALL_NEW"
};
dynamo.update(params, (err, data) => {
if (err) {
return reject(err);
}
console.log(data.Attributes);
});
Could not find any resources for updating an Json in a array.
After #notionquest's comment:
- Have not used any JsonMarshaller. Initially I added the empty array to attendees field like this:
{
"eventId": "20161029125458-df-d",
"name": "first",
"purpose": "test",
"location": "yokohama",
"dateArray": [],
"attendees": []
}
and then When a new attendee comes I add it to the attendees property like this:
const attendee = {
"attendeeName": "user1",
"personalizedDateSelection": {"today": "free"}
}
const attendeeList = [attendee];
const eventId = "20161029125458-df-d";
const params = {
TableName: "event",
Key: {
"eventId": eventId
},
UpdateExpression: "SET attendees = list_append(attendees, :attendee)",
ExpressionAttributeValues: {
":attendee" : attendeeList
},
ReturnValues: "ALL_NEW"
};
dynamo.update(params, (err, data) => {
if (err) {
return reject(err);
}
console.log("in update dynamo");
console.log(data.Attributes);
});
As you have seen in the above snippets, initially I add empty [] array and add a new attendee using the above code. Now, How do I update a specific JSON in an array. If you say that is not possible, what else can I try?
Should I try this :
Get the Full JSON.
Manipulate the JSOn and change the things I want in my nodeJS.
And then update the new JSON to dynamoDB.
But this consumes two calls to dynamoDB which seems to be inefficient.
Would like to know If there is any round way ?
you can store the index of list. while updating the list we can use them. For example ,
{
"data": {
"eventId": "20161029125458-df-d",
"name": "first",
"purpose": "test",
"location": "yokohama",
"dateArray": [],
"attendees": [
{
"index":0,
"attendeeId": "2016102973634-df",
"attendeeName": "lakshman",
"personalizedDateSelection": {}
},
{
"index":1,
"attendeeId": "2016102973634-tyyu",
"attendeeName": "diwaakar",
"personalizedDateSelection": {}
}
]
}
}
const params = {
TableName: "event",
Key: {
"eventId": eventId
},
UpdateExpression: "SET attendees[attendee.index].attendeeName = :value",
ExpressionAttributeValues: {
":value" : {"S":"karthik"}
},
ReturnValues: "ALL_NEW"
};
dynamo.update(params, (err, data) => {
if (err) {
return reject(err);
}
console.log(data.Attributes);
});
An example of an update query:
Data structure (saved in DynamoDB)
{
tenant_id: 'tenant_1',
users: {
user1: {
_id: 'user1',
email_address: 'test_email_1#gmail.com'
},
user2: {
_id: 'user2',
email_address: 'test_email_2#gmail.com'
}
}
}
Data for update (used in the params)
var user = {
email_address: 'updated#gmail.com'
}
Params
var params = {
TableName: 'tenant-Master',
Key: {
"tenant_id": 'tenant_1'
},
UpdateExpression: "set #users.user1 = :value",
ExpressionAttributeNames: {
"#users": "users"
},
ExpressionAttributeValues: {
":value": user,
},
};
Explanation
By switching to a map of maps from an array of maps we can now use UpdateExpression: "set #users.user1 = :value" to update our nested object at the map of users with the id of user1.
NOTE: This method as is will REPLACE the entire map object at users.user1. Some changes will need to be made if you want to keep pre-existing data.
I could not find any answer to query and update the JSON-array. I think this may be AWS profitable motive to not allow those features. If you need to query on a particular ID other than primary key, you need to make a secondary index which is cost effective. This secondary index cost is additional to the dyn
amoDB table cost.
Since, I did not want to pay extra bucks on secondary index, I changed my dynamoDB schema to the following:
{
"data": {
"eventId": "20161029125458-df-d",
"name": "first",
"purpose": "test",
"location": "yokohama",
"dateArray": [],
"attendees": {
"2016102973634-df": {
"attendeeId": "2016102973634-df",
"attendeeName": "lakshman",
"personalizedDateSelection": {}
},
"2016102973777-df": {
"attendeeId": "2016102973777-df",
"attendeeName": "ffff",
"personalizedDateSelection": {}
}
}
}
}
Changing attendees from [] to {}. This allows me the flexibility to query particular attendeeId and change the entire JSON associated with that. Even though, this is a redundant step, I do not want to spend extra bucks on my hobby project.
I am having problems formatting json to suit my needs for d3.
This is the incoming json.
{
"success": true,
"terms": "https://currencylayer.com/terms",
"privacy": "https://currencylayer.com/privacy",
"timeframe": true,
"start_date": "2010-03-01",
"end_date": "2010-03-04",
"source": "USD",
"quotes": {
"2010-03-01": {
"USDCAD": 1.31
},
"2010-03-02": {
"USDCAD": 1.32
},
"2010-03-03": {
"USDCAD": 1.34
}
}
}
i need to format it somehow to resemble the array below.
[
{"date":"2010-03-01","USDCAD": 1.31},
{"date":"2010-03-02","USDCAD": 1.32},
{"date":"2010-03-03","USDCAD": 1.33},
]
This is what i ended up with, not sure if it is the most efficient but it works.
d3.json(./somedata.json, function (response) {
var newdata = response.quotes;
data = []
for (var i in newdata) {
var datacopy = newdata[i];
datacopy.date = i;
data.push(datacopy)
}