Flutter Dart Http XML rest convert to Json

Question

I'm trying to get a album list from a server, the server uses xml and I'm trying to convert it to json but for some reason it doesn't work/comes back as null.


import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;
import 'package:xml2json/xml2json.dart';
import 'package:get/get.dart';
import 'package:xml/xml.dart' as xml;

class RecentlyAddedHome extends StatefulWidget {
  @override
  _RecentlyAddedHomState createState() => _RecentlyAddedHomState();
}

  Future> fetchRecentlyAddedAlbums() async{
  final aresponse = await http.get(recentAlbumsURL);
  xml2json.parse(aresponse.body);
  var jsondata = xml2json.toGData();
  var data = json.decode(jsondata);
  print(data);
  return AlbumsResponse.fromJson(data).toList();
}


class _RecentlyAddedHomState extends State {
  final Future> albumsresponse = fetchRecentlyAddedAlbums();
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Container(
        child: FutureBuilder(
          future: fetchRecentlyAddedAlbums(),
          builder: (context, data){
            if (data.hasData){
              List albumsresponse = data.data;
              return ListView.builder(
              itemCount: albumsresponse.length,
              itemBuilder: (context, index){
                return ListTile(
                  title: Text(albumsresponse[index].title,style: TextStyle(fontSize: 25.0),),
                );
              }, 
              );
            }
          },
        )
      )
    );
  }
}

this is my model for it

import 'package:xml/xml.dart' as xml;
import 'package:music_app_prototype/services/auth.dart';
import 'package:http/http.dart' as http;

 class AlbumsResponse {
  final String title;
  final int albumid;
  final String artist;
  final int coverart;

  AlbumsResponse({this.albumid, this.artist, this.coverart, this.title});

  factory AlbumsResponse.fromJson(Map json){
    return AlbumsResponse(
      title: json['_title'] as String,
      albumid: json['_albumid'] as int,
      artist: json['_artist'] as String,
      coverart: json['_coverart'] as int,
    );
  }
  get albumtitle => this.title;

  Future> toList() {}
}

and this is what the server sends me when i make the request

When i try to go to the Recently added page it says my build function returned null? I see that i get the data but it still doesn't show up. Can anyone help me, I'm not sure what I'm doing wrong, if i don't have to convert it from xml to json, how to do i work with it in xml form? Thanks!

chunhunghan · Accepted Answer

You can copy paste run full code below
Step 1: Parse with payloadFromJson and return data.subsonicResponse.albumList.album, see full code for detail Payload class definition

Payload payloadFromJson(String str) => Payload.fromJson(json.decode(str));
...
final aresponse = http.Response(xml, 200);

xml2json.parse(aresponse.body);
var jsondata = xml2json.toGData();
var data = payloadFromJson(jsondata);
var albumList = data.subsonicResponse.albumList.album;

return albumList;

Step 2: builder need to define type AsyncSnapshot> and check connectionState

 builder: (context, AsyncSnapshot> data) {
        switch (data.connectionState) {
          case ConnectionState.none:
            return Text('none');
          case ConnectionState.waiting:
            return Center(child: CircularProgressIndicator());
          case ConnectionState.active:
            return Text('');
          case ConnectionState.done:
            if (data.hasData) {

working demo

full code

import 'package:flutter/material.dart';
import 'package:xml2json/xml2json.dart';
import 'package:http/http.dart' as http;
import 'dart:convert';

Payload payloadFromJson(String str) => Payload.fromJson(json.decode(str));

String payloadToJson(Payload data) => json.encode(data.toJson());

class Payload {
  Payload({
    this.version,
    this.encoding,
    this.subsonicResponse,
  });

  String version;
  String encoding;
  SubsonicResponse subsonicResponse;

  factory Payload.fromJson(Map json) => Payload(
        version: json["version"],
        encoding: json["encoding"],
        subsonicResponse: SubsonicResponse.fromJson(json["subsonic-response"]),
      );

  Map toJson() => {
        "version": version,
        "encoding": encoding,
        "subsonic-response": subsonicResponse.toJson(),
      };
}

class SubsonicResponse {
  SubsonicResponse({
    this.status,
    this.version,
    this.xmlns,
    this.albumList,
  });

  String status;
  String version;
  String xmlns;
  AlbumList albumList;

  factory SubsonicResponse.fromJson(Map json) =>
      SubsonicResponse(
        status: json["status"],
        version: json["version"],
        xmlns: json["xmlns"],
        albumList: AlbumList.fromJson(json["albumList"]),
      );

  Map toJson() => {
        "status": status,
        "version": version,
        "xmlns": xmlns,
        "albumList": albumList.toJson(),
      };
}

class AlbumList {
  AlbumList({
    this.album,
  });

  List album;

  factory AlbumList.fromJson(Map json) => AlbumList(
        album: List.from(
            json["album"].map((x) => AlbumsResponse.fromJson(x))),
      );

  Map toJson() => {
        "album": List.from(album.map((x) => x.toJson())),
      };
}

class AlbumsResponse {
  AlbumsResponse({
    this.id,
    this.parent,
    this.isDir,
    this.title,
    this.album,
    this.artist,
    this.genre,
    this.coverArt,
    this.playCount,
    this.created,
    this.year,
  });

  String id;
  String parent;
  String isDir;
  String title;
  String album;
  String artist;
  String genre;
  String coverArt;
  String playCount;
  DateTime created;
  String year;

  factory AlbumsResponse.fromJson(Map json) => AlbumsResponse(
        id: json["id"],
        parent: json["parent"],
        isDir: json["isDir"],
        title: json["title"],
        album: json["album"],
        artist: json["artist"],
        genre: json["genre"],
        coverArt: json["coverArt"],
        playCount: json["playCount"],
        created: DateTime.parse(json["created"]),
        year: json["year"] == null ? null : json["year"],
      );

  Map toJson() => {
        "id": id,
        "parent": parent,
        "isDir": isDir,
        "title": title,
        "album": album,
        "artist": artist,
        "genre": genre,
        "coverArt": coverArt,
        "playCount": playCount,
        "created": created.toIso8601String(),
        "year": year == null ? null : year,
      };
}

Xml2Json xml2json = Xml2Json();
Future> fetchRecentlyAddedAlbums() async {
  //final aresponse = await http.get(recentAlbumsURL);
  String xml = '''
  

    
        
        
        
        
        
        
        
        
        
        
    

''';

  final aresponse = http.Response(xml, 200);

  xml2json.parse(aresponse.body);
  var jsondata = xml2json.toGData();
  var data = payloadFromJson(jsondata);
  var albumList = data.subsonicResponse.albumList.album;
  //print(albumList.toString());
  return albumList;
}

class RecentlyAddedHome extends StatefulWidget {
  @override
  _RecentlyAddedHomState createState() => _RecentlyAddedHomState();
}

class _RecentlyAddedHomState extends State {
  final Future> albumsresponse =
      fetchRecentlyAddedAlbums();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        body: Container(
            child: FutureBuilder(
      future: fetchRecentlyAddedAlbums(),
      builder: (context, AsyncSnapshot> data) {
        switch (data.connectionState) {
          case ConnectionState.none:
            return Text('none');
          case ConnectionState.waiting:
            return Center(child: CircularProgressIndicator());
          case ConnectionState.active:
            return Text('');
          case ConnectionState.done:
            if (data.hasData) {
              List albumsresponse = data.data;
              return ListView.builder(
                itemCount: albumsresponse.length,
                itemBuilder: (context, index) {
                  return ListTile(
                    title: Text(
                      albumsresponse[index].title,
                      style: TextStyle(fontSize: 25.0),
                    ),
                  );
                },
              );
            }
        }
      },
    )));
  }
}

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: RecentlyAddedHome(),
    );
  }
}

Flutter Dart Http XML rest convert to Json

Answers (1)

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