Making HTTP request to my localhost on flutter not working

Question

I am trying to get my data to show on my flutter app from a api (formatted in json) created by connecting mysql on node.js with express.

i am running this error in android studio console

[VERBOSE-2:dart_error.cc(16)] Unhandled exception:
type '_InternalLinkedHashMap<String, dynamic>' is not a subtype of type 
'List<dynamic>'

the api currently looks like this

{
    "error": false,
        "data": [
           {
              "name": "conner",
              "age": 24
            },
            {
              "name": "andrew",
              "age": 20
            }
         ],
         "message": "Todos list."
         }

I am using this tutorial and just replaced his value "title" with mine "name", https://www.youtube.com/watch?v=-PRrdG163to

here is the code I'm running

import 'dart:async';
import 'dart:convert';

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;

void main() {
  runApp(new MaterialApp(
    home: new HomePage(),
  ));
}

class HomePage extends StatefulWidget {
  @override
  HomePageState createState() => new HomePageState();
}
class HomePageState extends State<HomePage> {

  Map<String,dynamic> data;

  Future<String> getData() async {
    var response = await http.get(
        Uri.encodeFull("http://10.1.0.109:8080/names"),
        headers: {
          "Accept": "application/json"
        }
    );

    this.setState(() {
      data = JSON.decode(response.body);
    });
    print (data[1]["data"]);

    return "Success!";
  }

  @override
  void initState() {
    super.initState();
    this.getData();
  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text("Listviews"),
      ),
      body: new ListView.builder(
        itemCount: data == null ? 0 : data["data"].length,
        itemBuilder: (BuildContext context, int index) {
          return new Card(
            child: new Text(data[index]["data"]),
          );
        },
      ),
    );
  }
}

Raouf Rahiche · Accepted Answer · 2018-07-12 16:15:15Z

1

the problem is in the structure of your JSON file it's not the same as in the tutorial so try this

data["data"][1]["name"]

NOTE :

change data from list to var or Map<String,dynamic>

Map<String,dynamic> data;

after that you need to get the list length so in the itemCount change it to

itemCount: data == null ? 0 : data["data"].length,

Full Example

edited Jul 12, 2018 at 16:15

answered Jul 12, 2018 at 15:13

Raouf Rahiche

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13 Comments

Mfreeman Over a year ago

but name needs to be a string doesn't it, ill get compiling errors otherwise

Raouf Rahiche Over a year ago

sorry i did i small typo in the code try the edited one

Raouf Rahiche Over a year ago

see the edited answer i tried it and it works the problem was on the type of the data variable i didn't notice that its not a list

Raouf Rahiche Over a year ago

sorry again i updated my answer the second problem was on the list length

Raouf Rahiche Over a year ago

even with this? if so the problem would be in the API it self. did you try to test it on the browser ?

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