How to make a webserver in a flutter app? - flutter

I want to make a webserver locally on the flutter android app that can serve a website. Like that i can connect from any computer using the android device's local IP and the website will appear in the browser.
If you are familiar with Airdroid, it has this feature and i want apply it to my app.
My question is: Is this possible using dart code or do i need to use MethodChannel with existing android libraries? If so what is the best one out there that i can use?

It is possible to do. Take a look at the http_server library that was developed by the Dart team.
Here is a code snippet to get you going.
HttpServer.bind('0.0.0.0', 8080).then((server) {
server.transform(HttpBodyHandler()).listen((HttpRequestBody body) async {
switch (body.request.uri.toString()) {
case '/':
String _content = await _loadStatic('index.html');
body.request.response.statusCode = 200;
body.request.response.headers.set("Content-Type", "text/html; charset=utf-8");
body.request.response.write(_content);
body.request.response.close();
break;
default:
body.request.response.statusCode = 404;
body.request.response.write('Not Found');
body.request.response.close();
}
});
});

Related

Opening Google calendar from Flutter app (Deep Linking)

I want to open Google calendar app more specifically the create event page in the app from my another flutter app.
I am using the URL launcher package but it opens the app in chrome
What change should I make in the URL so that the add event page opens directly in the google calendar app.
Currently my URL looks like below
https://calendar.google.com/calendar/u/0/r/eventedit?dates=20210226T033000/20210226T040000&ctz=Asia/Calcutta&location&text=Blawsome:+A+Crystal+Alchemy+Healing+Meditation&details=Parth+Pitroda
My code for that part is as below
if (await canLaunchUrl(Uri.parse('https://calendar.google.com/calendar/u/0/r/eventedit?dates=20210226T033000/20210226T040000&ctz=Asia/Calcutta&location&text=Blawsome:+A+Crystal+Alchemy+Healing+Meditation&details=Parth+Pitroda'))) {
await launchUrl(
Uri.parse('https://calendar.google.com/calendar/u/0/r/eventedit?dates=20210226T033000/20210226T040000&ctz=Asia/Calcutta&location&text=Blawsome:+A+Crystal+Alchemy+Healing+Meditation&details=Parth+Pitroda'),
mode: LaunchMode.externalApplication);
} else {
throw 'Could not launch URL';
}
rathe than using a HTTP request, you could use googleapis package from https://pub.dev which has inbuilt methods to create Google Calender events directly within the Calender app.
Check package and documentation here.
Happy coding!

Download image in mobile in flutter web

I created a flutter web app that creates an image and generates the base64 data. so I used AnchorElement in the HTML package to download the image to the client, it works on mac and windows but when I want to be downloaded on mobile nothing happen at all.
any clue?
code:
Future<void> downloadImage(Uint8List data8) async {
try {
final base64data = base64Encode(data8);
final a = html.AnchorElement(href: 'data:image/jpeg;base64,$base64data');
a.download = 'image.jpg';
a.click();
a.remove();
} catch (e) {
print(e);
}
}
In general mobile apps need rights to access certain resource, e.g. access the network.
Search for entitlement on iOS like this and manifest on Android.
You need to set these rights in the iOS or Android project. Without this rights, access gets simply denied.

Create a button to open app from flutter web

I would like to create an app in Flutter. The web version contains a button that should open version of android or IOS app according user platform if mobile version of app was installed (like an app install or open banner).
How should I detect is app installed in web flutter?
update:
I tried below code using import 'package:universal_html/html.dart' pakage:
window.location.href = (defaultTargetPlatform ==
TargetPlatform.android)
? 'https://play.google.com/store/apps/details?id=com.amazon.mShop.android.shopping'
: 'https://apps.apple.com/us/app/amazon-shopping/id297606951';
But this just open the store. I'm looking for a solution to open app directly if it was installed.
If this is fine for you, you can use an URL launcher. This way it opens the App store or play store and the user can either download the App or open it.
For Example flutter has a package that does most of this work:
https://github.com/Purus/launch_review
LaunchReview.launch(androidAppId: "yourpackagename", iOSAppId: "appid");
You just need to pass your package name and on ios your app ID
You could also use an URL Launcher:
https://pub.dev/packages/url_launcher
The code would be similar to this:
_launchURL(String url) async {
if (await canLaunch(url)) {
await launch(url);
}
else {
throw 'Could not launch $url';
}
}
URL Example
try {
launch("market://details?id=" + appPackageName);
} on PlatformException catch(e) {
launch("https://play.google.com/store/apps/details?id=" + appPackageName);
} finally {
launch("https://play.google.com/store/apps/details?id=" + appPackageName);
}
Note this code needs to be adapted
Also see this tutorial for help: https://flutteragency.com/open-appstore-playstore-url-in-flutter/
Edit:
If you want to directly open another app you can use something like this:
https://pub.dev/packages/external_app_launcher/
flutter pub add external_app_launcher
The Code would look like this then:
await LaunchApp.openApp(
androidPackageName: 'net.pulsesecure.pulsesecure',
iosUrlScheme: 'pulsesecure://',
appStoreLink: 'itms-apps://itunes.apple.com/us/app/pulse secure/id945832041',// openStore: false
);
// Enter the package name of the App you want to open and for iOS add the URLscheme to the Info.plist file.
// The `openStore` argument decides whether the app redirects to PlayStore or AppStore.
// For testing purpose you can enter com.instagram.android
More infos regarding implementation and additional setup infos you can find here: https://pub.dev/packages/external_app_launcher in the Readme

Is there a way to launch Safari or some other external browser on URLs in Flutter apps on iOS?

I have this code:
import 'package:url_launcher/url_launcher.dart';
...
await launch("https://example.org/bigprizes");
It launches a web view within the app on iOS. Instead, I want it to launch in Safari or some other external browser of the user's choice. Is there a way to do that in Flutter?
Look at Step 4 in https://www.digitalocean.com/community/tutorials/flutter-url-launcher
await launch("https://example.org/bigprizes", forceSafariVC: false);
url_launcher plugin (https://pub.dev/packages/url_launcher) has methods launchUrl() and launchUrlString() which both has a property mode where you can specify how the app will open the URL. More details on the Launch mode documentation
Basically you can call it like this:
static Future<void> launchURL(String url) async {
if (await canLaunchUrlString(url)) {
// Passes the URL to the OS to be handled by another application.
await launchUrlString(url, mode: LaunchMode.externalApplication);
} else {
throw 'Could not launch $url';
}
}
check this package https://pub.dev/packages/flutter_linkify it's may be useful for your project

How to inspect network calls in flutter application

I'm making network calls in flutter by using HTTP package, i want to know which type of response is getting for those calls
In Flutter 17.1 version, they given cool feature for inspecting the Network calls,
open developer tools by tapping on open DevTools icon (which is in debug console of android studio) as show in below image
After that it will the install the tools and open Dart dev tools in a browser as shown in below image
Click on the right side top corner flask icon(which is highlighted in the above image),
it will refresh the page automatically and display the Network option in the tool bar as show in below image
Now you can inspect your each and every call
Use flutter_stetho dart package to inspect network calls
Visit https://pub.dev/packages/flutter_stetho
Include this to your package's pubspec.yaml
dependencies:
flutter_stetho:(version) >> for example flutter_stetho: ^0.4.1
Note: Based on dart version only, choose the Stetho package version
For Flutter 1.7.x with Dart 2.4, use version 0.3.0
For Flutter 1.8.x+ with Dart 2.5, use version 0.4.0 or higher
You can use devtools network inspector:
Open command platte
Search for openDevToolsNetwork
This is an example of me that returns a list of hotels from web service:
List<Hotel> list = list();
var res = await http.get('http://api-dadepardazan.nikoosoft.ir/api/cms/hotels',
headers: {"Access-Token": "bt316x312ba44c6183aa81c2ce0d3eff", "Client-Id":"20629heeba32cc87fra6637b257d73"});
if (res.statusCode == 200) {
try {
var data = json.decode(res.body);
var rest = data["result"];
for (var model in rest) {
list.add(Hotel.fromJson(model));
}
print('list loaded from web service');
} on FormatException catch (e) {
print("That string didn't look like Json.");
} on NoSuchMethodError catch (e) {
print('That string was null!');
}
} else {
print('Failed to call service');
}
You can use charles download here
Now add proxy in wifi connection in real device (No need to do for simulator or emulator).
Now do below code to configure setup with flutter Dio package.
Dio dio = new Dio();
(dio.httpClientAdapter as DefaultHttpClientAdapter).onHttpClientCreate =
(HttpClient client) {
client.findProxy = (uri) {
return "PROXY <Your_PC_IP_Where_Charles_is_running>:8888";
};
client.badCertificateCallback =
(X509Certificate cert, String host, int port) => true;
};
If you just want to know what the reponse.body is I don't think that you need a separate library to inspect network calls in Flutter when you already have an powerful http library by the official Flutter Dev Team.
Sample Code:
http.get("http://api.urbandictionary.com/v0/define?term=stackoverflow").then((response){
print("Status Code: ${response.statusCode}");//200 if successful
print("Response Body: ${response.body}");
// You can examine the response object either by referring the docs or using he suggestions you get in Android Studio / VS Code
})
The typical way to inspect network traffic from mobile apps is via a proxy. A superb tool for this is Charles Proxy.
Once you have Charles set up you don't actually need any additional Flutter plugins or packages to get it working, but you do need to set up Flutter to route through your local proxy (unfortunately Flutter ignores your device settings):
class MyProxyHttpOverride extends HttpOverrides {
#override
HttpClient createHttpClient(SecurityContext context) {
return super.createHttpClient(context)
..findProxy = (uri) {
return "PROXY localhost:8888;";
}
..badCertificateCallback =
(X509Certificate cert, String host, int port) => true;
}
}
// In your main.dart
HttpOverrides.global = MyProxyHttpOverride();
Of course, you'll need to change localhost:8888 to whatever your proxy settings are.
I also wrote a more detailed write up about this solution here.
You can use request_inspector to see you request