WebViewController. Exception has occurred. ArgumentError (Invalid argument(s): Missing scheme in uri: null) - flutter

Question

I am trying to pass data from previous page(news_card.dart) to another page(news_details.dart) to view in WebViewController. but for loadRequest(Uri.parse(widget.link)) I have received an error "Exception has occurred.
ArgumentError (Invalid argument(s): Missing scheme in uri: null)"
Here is my code for news_card.dart
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
import 'package:flutter/src/widgets/container.dart';
import 'package:flutter/src/widgets/framework.dart';
import 'package:lumi_news/page/news/news_details.dart';
class NewsCard extends StatelessWidget {
final CollectionReference collectionReference;
NewsCard({super.key, required this.collectionReference});
PageController? _controller;
#override
Widget build(BuildContext context) {
return Scaffold(
body: StreamBuilder<QuerySnapshot>(
stream: collectionReference.snapshots(),
builder: (BuildContext context, AsyncSnapshot snapshot) {
if (snapshot.hasError) {
return Text("error");
}
if (snapshot.hasData) {
QuerySnapshot querySnapshot = snapshot.data;
List<QueryDocumentSnapshot> documents = querySnapshot.docs;
List<Map> items = documents
.map((e) => {
'id': e.id,
'newsTitle': e['newsTitle'],
'publisherName': e['publisherName'],
'imageUrl': e['imageUrl'],
'publisherImageUrl': e['publisherImageUrl'],
'publisherRectangleUrl': e['publisherRectangleUrl'],
'updated': e['updated'],
'link"': e['link'],
})
.toList();
return ListView.builder(
itemCount: items.length,
itemBuilder: (context, index) {
Map thisItem = items[index];
return Container(
//padding: const EdgeInsets.fromLTRB(10, 10, 10, 0),
height: 150,
width: double.maxFinite,
child: GestureDetector(
onTap: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => NewsDetails(
link: '${thisItem['link']}',
image: '${thisItem['publisherImageUrl']}',
title: '${thisItem['publisherName']}',
)));
},
child: Card(
elevation: 3,
child: Row(
children: <Widget>[
Container(
width: 110,
margin: EdgeInsets.fromLTRB(10, 10, 10, 10),
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(5),
color: Colors.white,
image: DecorationImage(
fit: BoxFit.fill,
image: NetworkImage('${thisItem['imageUrl']}'),
),
),
),
Container(
child: Expanded(
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
SizedBox(
height: 10,
),
Text(
'${thisItem['publisherName']}',
style: TextStyle(
color: Colors.grey,
fontSize: 12,
),
),
Text(
'${thisItem['newsTitle']}',
maxLines: 3,
style: TextStyle(
color: Colors.black,
fontWeight: FontWeight.bold,
fontSize: 14,
),
),
SizedBox(
height: 30,
),
Text(
'${thisItem['updated']}',
style: TextStyle(
color: Colors.grey,
fontSize: 12,
),
),
],
),
),
),
],
),
),
),
);
},
);
}
return Center(child: CircularProgressIndicator());
},
),
);
}
}
and here news_detail.dart
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
import 'package:flutter/src/widgets/container.dart';
import 'package:flutter/src/widgets/framework.dart';
import 'package:webview_flutter/webview_flutter.dart';
class NewsDetails extends StatefulWidget {
final String link;
final String title;
final String image;
NewsDetails({required this.link, required this.title, required this.image});
#override
State<NewsDetails> createState() => _NewsDetailsState(link, title, image);
}
class _NewsDetailsState extends State<NewsDetails> {
WebViewController? _controller;
final String link;
final String title;
final String image;
_NewsDetailsState(this.link, this.image, this.title);
#override
void initState() {
// TODO: implement initState
super.initState();
_controller = WebViewController()
..setJavaScriptMode(JavaScriptMode.unrestricted)
..setBackgroundColor(const Color(0x00000000))
..setNavigationDelegate(
NavigationDelegate(
onProgress: (int progress) {
// Update loading bar.
},
onPageStarted: (String url) {},
onPageFinished: (String url) {},
onWebResourceError: (WebResourceError error) {},
onNavigationRequest: (NavigationRequest request) {
if (request.url.startsWith('https://www.youtube.com/')) {
return NavigationDecision.prevent;
}
return NavigationDecision.navigate;
},
),
)
..loadRequest(Uri.parse(widget.link));
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
elevation: 1,
backgroundColor: Colors.white,
leading: GestureDetector(
onTap: () {
Navigator.pop(context);
},
child: Icon(
Icons.arrow_back,
color: Colors.black,
),
),
title: Container(
width: double.maxFinite,
child: Row(
children: <Widget>[
Container(
child: Image.network(
widget.image,
fit: BoxFit.contain,
height: 32,
),
),
Container(
padding: EdgeInsets.only(left: 5),
child: Text(
widget.title,
style: TextStyle(color: Colors.black),
),
)
],
),
),
),
body: WebViewWidget(controller: _controller!),
);
}
}
Does anyone know how to solve this? Thanks for any help !