Develop Reference

Flutter WebView: If no internet show different content

I have a flutter web view app. I would like to have an offline screen with text and the button "try again".
If there is no internet connection (in real-time, no need to refresh and click to check connection), once he lost connection, show the screen with text and try again button. Then if the connection is successfully get the user back to the page where he was.
My current main.dart:
import 'package:webview_flutter/webview_flutter.dart';
void main() {
runApp(
const MaterialApp(
home: WebViewApp(),
),
);
}
class WebViewApp extends StatefulWidget {
const WebViewApp({Key? key}) : super(key: key);
#override
State<WebViewApp> createState() => _WebViewAppState();
}
class _WebViewAppState extends State<WebViewApp> {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
backgroundColor: Colors.white,
elevation: 0,
toolbarHeight: 0,
),
body: const WebView(
javascriptMode: JavascriptMode.unrestricted,
initialUrl: 'https://google.com',
),
);
}
}

You can use a package like internet connection checker. Example this
One. And check for internet status like
bool result = await InternetConnectionChecker().hasConnection;
if(result == true) {
return Webview();
} else {
print('No internet :( Reason:');
return Center(
child: Text(" no internet"),
);
}

How to show image from firebase storage in flutter?

This is my storage. I want the image to shown on my app directly. THE REQUEST REACHES the storage, I checked from the statistics. But cannot take it, also I changed rules to that everyone can download them. But still nothing. I tried solutions from this page: Flutter Load Image from Firebase Storage
But they didn't work at all. Maybe I've put the codes in the wrong places, I don't know. How do I do this? Can you please help? Here's my whole code of main.dart:
import 'package:firebase_storage/firebase_storage.dart';
import 'package:flutter/material.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_core/firebase_core.dart';
void main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
runApp(MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.red,
visualDensity: VisualDensity.adaptivePlatformDensity,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
var url;
void _incrementCounter() {
setState(() {
_counter++;
});
}
Widget _buildListItem(BuildContext context, DocumentSnapshot document) {
String mezunD;
if (document.data()['mezunDurumu'] == false) {
mezunD = "mezun değil";
}
if (document.data()['mezunDurumu'] == true) {
mezunD = "mezun";
}
var listTile = ListTile(
title: Column(
children: [
Expanded(
child: Text(
"Ad Soyad: " + document.data()['adSoyad'],
),
),
Expanded(
child: Text(
"Yaş: " + document.data()['yas'].toString(),
),
),
Expanded(
child: Text(
"Doğum Tarihi: " + document.data()['dogumTarihi'],
),
),
Expanded(
child: Text("Mezun Durumu: " + mezunD),
),
//I wanna show image right under these.
],
),
);
return listTile;
}
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Öğrenci Durumu"),
),
body: StreamBuilder(
stream: FirebaseFirestore.instance.collection('tablo').snapshots(),
builder: (context, snapshot) {
if (!snapshot.hasData) return const Text('Loading...');
return ListView.builder(
itemExtent: 100.0,
itemCount: snapshot.data.documents.length,
itemBuilder: (context, index) =>
_buildListItem(context, snapshot.data.documents[index]),
);
}),
);
}
}

If you click in the firebase storage on the image then you can see on right side a preview of the image. under this preview is a blue link. if you tap on the blue link you open the image in full-size in the browser with the full image-address including the access-token. copy the full url of this browser window and use it in flutter. for example with:
Image.network(url);
or the package "cached_network_image"

Methods are not getting executed in the written order inside onPressed

Im trying to create a flutter app with a simple raised button that does the following:
sends an sms in the background using the sms package opens a webpage
2. in the app(only for 5 seconds) using url_launcher opens the phones
3. native app for making a voice call with the onPressed property.
And I wanted it to be in this order so that I can make the phone call at the end. However, the inside the onPressed opens the native phone call app first, which doesnt let my web page open unless I exit out of the phone call app.
Im having a hard time understanding why the phone call native app is opened first, even though I make the call the _makePhoneCall() method only after I make the _launchInApp(toLaunch) call. sendSMS() is being called correctly
How can I set this in a way that the phone call native app is called only after the webpage is opened in the app and follows the order? Any help would be great
Below is the piece of code:
import 'package:flutter/material.dart';
import 'package:url_launcher/url_launcher.dart';
import 'package:sms/sms.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Packages testing',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Packages testing'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
String _phone = '';
_launchInApp(String url) async {
if (await canLaunch(url)) {
await launch(
url,
forceSafariVC: true,
forceWebView: true,
headers: <String, String>{'my_header_key': 'my_header_value'},
);
} else {
throw 'Could not launch $url';
}
}
_makePhoneCall(String url) async {
if (await canLaunch(url)) {
await launch(url);
} else {
throw 'Could not launch $url';
}
}
void sendSMS() {
SmsSender sender = new SmsSender();
sender.sendSms(new SmsMessage(_phone, 'Testing Handset'));
}
#override
Widget build(BuildContext context) {
const String toLaunch = 'https://flutter.dev/';
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: ListView(
children: <Widget>[
Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Padding(
padding: const EdgeInsets.all(16.0),
child: TextField(
onChanged: (String text) => _phone = text,
decoration:
const InputDecoration(hintText: 'Phone Number')),
),
FlatButton(
onPressed: () => setState(() {
sendSMS();
_launchInApp(toLaunch);
_makePhoneCall('tel:$_phone');
}),
child: const Text('Run All'),
),
const Padding(padding: EdgeInsets.all(16.0)),
],
),
],
),
);
}
}

You will have to use the await keyword before the _launchInApp function to make it work properly. Try the following code.
FlatButton(
onPressed: () aync {
sendSMS();
await _launchInApp(toLaunch);
_makePhoneCall('tel:$_phone');
}),
child: const Text('Run All'),
),

You created async functions but when you called them you did not specify that you want to wait for them to complete. Add the await keyword in OnPressed

Flutter get source URL along with Text shared from web page

I am new to Flutter. I want to get the text along with its source. Currently, I am using receive_sharing_intent which is serving the purpose of TextStream and Url individually.
I want to share the copied text from the browser and keep its URL along with it.
I followed this doc hence my main.dart is same as:
import 'package:flutter/material.dart';
import 'dart:async';
import 'package:receive_sharing_intent/receive_sharing_intent.dart';
void main() => runApp(MyApp());
class MyApp extends StatefulWidget {
#override
_MyAppState createState() => _MyAppState();
}
class _MyAppState extends State<MyApp> {
StreamSubscription _intentDataStreamSubscription;
List<SharedMediaFile> _sharedFiles;
String _sharedText;
#override
void initState() {
super.initState();
// For sharing or opening urls/text coming from outside the app while the app is in the memory
_intentDataStreamSubscription =
ReceiveSharingIntent.getTextStream().listen((String value) {
setState(() {
_sharedText = value;
});
}, onError: (err) {
print("getLinkStream error: $err");
});
// For sharing or opening urls/text coming from outside the app while the app is closed
ReceiveSharingIntent.getInitialText().then((String value) {
setState(() {
_sharedText = value;
});
});
}
#override
void dispose() {
_intentDataStreamSubscription.cancel();
super.dispose();
}
#override
Widget build(BuildContext context) {
const textStyleBold = const TextStyle(fontWeight: FontWeight.bold);
return MaterialApp(
home: Scaffold(
appBar: AppBar(
title: const Text('Plugin example app'),
),
body: Center(
child: Column(
children: <Widget>[
Text("Shared files:", style: textStyleBold),
Text(_sharedFiles?.map((f)=> f.path)?.join(",") ?? ""),
SizedBox(height: 100),
Text("Shared urls/text:", style: textStyleBold),
Text(_sharedText ?? "")
],
),
),
),
);
}
}
Any suggestions on how to proceed to this or any Reference will work.
Thanks!!

JSON file data not loading after install flutter app

I am a new learner of android app development with Flutter framework. I am trying to load a JSON file from asset and show the data by listview. It's working with development mode (flutter run) but when I build the apk and install it on my android phone the JSON file is not loading and no data showing on my app.
flutter build apk
flutter install
I have tried with this code.
import 'package:flutter/material.dart';
import 'dart:async' show Future;
import 'package:flutter/services.dart' show rootBundle;
import 'dart:convert';
void main() {
runApp(new MaterialApp(
home: new HomePage(),
));
}
class HomePage extends StatefulWidget {
#override
HomePageState createState() => new HomePageState();
}
class HomePageState extends State<HomePage> {
List data;
Future<String> loadZipCodes() async {
var jsonString = await rootBundle.loadString('assets/data/cse.json');
data = JSON.decode(jsonString);
print(data[1]);
return 'success';
}
#override
void initState() {
this.loadZipCodes();
}
#override
Widget build(BuildContext context) {
return new Scaffold(
appBar: new AppBar(
title: new Text('Home'),
),
body: new ListView.builder(
itemCount: data == null ? 0 : data.length,
itemBuilder: (BuildContext context, int index) {
return new Card(
child: new Container(
padding: new EdgeInsets.all(15.0),
child: new Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: <Widget>[
new Text(data[index]["sort_term"],style: new TextStyle(fontSize: 16.0, fontWeight: FontWeight.bold)),
new Text(data[index]["long_term"])
])));
},
));
}
}
Please help me to figure out what is the problem going on. Thanks in advance.

give this permission in app>main>AndroidManifest.xml
<uses-permission android:name="android.permission.INTERNET">
set internet permission in the above file