how to access provider in initstate function of stateful widget code example

Example 1: use provider on start in stateless widget

When using Provider for state management you don't need to use StatefullWidget, so how can you call a method of the ChangeNotifier on start of the app?

You can simply do that in the constructor of the ChangeNotifier, so that when you point out VideosProvider() to the ChangeNotifierProvider Builder the constructor will get called the first time the provider constructs the VideosProvider, so:

PlayList.dart:

class Playlist extends StatelessWidget {

@override
Widget build(BuildContext context) {
  final videosState = Provider.of(context);
  var videos = videosState.playlist;
  return Scaffold(
    appBar: AppBar(
      title: Text('My Videos'),
    ),
    body: RefreshIndicator(
      child: Container(
        width: double.infinity,
        height: double.infinity,
        child: videos.length
            ? ListView.builder(
                itemBuilder: (BuildContext context, index) {
                  return _videoListItem(context, index, videos, videosState);
                },
                itemCount: videos.length,
              )
            : Center(
                child: CircularProgressIndicator(),
              ),
      ),
      onRefresh: () => null,
    ),
  );
} }

VideosProvider.dart:

class VideosProvider with ChangeNotifier {

  VideosProvider(){
    fetchVideosList();
  }

  List _playlist;
  int _currentVideoId;  
  get playlist => _playlist;

  void setPlayList(videosList) {
     _playlist = videosList;
  }

  Future fetchVideosList() async {
    http.Response response =
    await http.get("http://192.168.1.22:3000/videos-list/");

    print(json.decode(response.body));
    videos = json.decode(response.body)["data"];
    setPlayList(videos);
    return videos;
 }
}

Example 2: flutter constructor in statefull widget

STATEFUL WIDGET CONSTRUCTOR

class ServerIpText extends StatefulWidget {
  final String serverIP;

  const ServerIpText ({ Key key, this.serverIP }): super(key: key);

  @override
  _ServerIpTextState createState() => _ServerIpTextState();
}

class _ServerIpTextState extends State {
  @override
  Widget build(BuildContext context) {
    return Text(widget.serverIP);
  }
}

class AnotherClass extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Center(
      child: ServerIpText(serverIP: "127.0.0.1")
    );
  }
}