flutter embedded pos printer (Like: Android Q2 device) - flutter

Already I have built a flutter project. Now I need to print from a pos embedded device. I am googling, but I don't get any solution.
Please help me if there is any solution.
Actually I need for Android Q2 device
 

I have the same device and i already built flutter application , and ran into the same probleme .
I contacted the company and they provided me with android sdk so i added a channel and called the print from the flutter code.

EDIT:
In your case, you can download the SDK provided by the company and write native code to print the receipt.
example:
in flutter
static const platform = const MethodChannel('com.example.myapplication');
Future<void> _print() async {
try {
final bool result = await platform.invokeMethod('print',{"data":Printdata});
if (result) {
// success
} else {
// failed
}
} on PlatformException catch (e) {
//failed to print
}
}
Then in the Main.java / Main.kt implement the method from the SDK documentation
example:
public void onMethodCall(MethodCall call, MethodChannel.Result result) {
if (call.method.equals("print")) {
data = call.argument("data");
// Code from SDK documentation
} else {
result.notImplemented();
}
}
ref: Example Nativcode in flutter
Add third party SDK to android

Try this library "flutter_bluetooth_serial" and connect to the printer via direct mac address like this:
BluetoothConnection connection = await BluetoothConnection.toAddress("mac");

Related

How to retrieve logcat in Flutter?

How do you get the output written to logcat back into the Flutter app that caused it? Or simpler asked: How to read logcat in Flutter?
The problem is this:
The app uses a stack of Android plugins to communicate with some custom hardware through Bluetooth. Those Android plugins write extensively to logcat. Now, for debugging, it would be very helpful to be able to read all the messages the App (including native plugins) has written to logcat. Question is, is this somehow possible?
How would you tackle that?
Check out the plugin called logcat on pub.dev.
Sadly, it seems to be no longer maintained and isn't updated for null safety.
But you can check out the source code here and see how the plugin gets access to the android logcat.
Because the logcat is a native thing, you'll have to use a MethodChannel to call a Java/Kotlin function:
// define MethodChannel
final platform = const MethodChannel('app.channel.logcat');
// call native method
logs = await platform.invokeMethod('execLogcat');
And the native part:
public class LogcatPlugin implements MethodCallHandler {
public static void registerWith(Registrar registrar) {
final MethodChannel channel = new MethodChannel(registrar.messenger(), "app.channel.logcat");
channel.setMethodCallHandler(new LogcatPlugin());
}
#Override
public void onMethodCall(MethodCall call, Result result) {
if (call.method.equals("execLogcat")) {
String logs = getLogs();
if (logs != null) {
result.success(logs);
} else {
result.error("UNAVAILABLE", "logs not available.", null);
}
} else {
result.notImplemented();
}
}
String getLogs() {
try {
Process process = Runtime.getRuntime().exec("logcat -d");
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(process.getInputStream()));
StringBuilder log = new StringBuilder();
String line;
while ((line = bufferedReader.readLine()) != null) {
log.append(line);
}
return log.toString();
} catch (IOException e) {
return "EXCEPTION" + e.toString();
}
}
}
The code samples are from github.com/pharshdev/logcat.
Maybe you can just fork the git repo and migrate it to null safety if needed.
Check the plugin called logcat_monitor on pub.dev.
Its biggest advantage over the other logcat plugin is that it allows continuous monitoring of logcat messages.
Follows a screenshot example:
how to use
Add the dependencies:
dependencies:
logcat_monitor: ^0.0.4
Create a function to consume the logcat messages
void _mylistenStream(dynamic value) {
if (value is String) {
_logBuffer.writeln(value);
}
}
Register your function as a listener to get logs then use it in anyway within your app.
LogcatMonitor.addListen(_mylistenStream);
Start the logcat monitor passing the filter parameters as defined in logcat tool.
await LogcatMonitor.startMonitor("*.*");

Flutter Signalr Listener is not connected in 2nd screen after migrated to null safety stable version

Chatting was working perfectly before migrating to null safety using signalr. But after migrating It is not working in chatting part.
Scenario is like there are 2 screens where I am using signalr.
1)Chatlist.
2)Chatting with person.
listener in Chatlist is perfect but in 2nd screen it is not working(Just worked when I installed and run for the 1st time). Weird issue.
All was working in old. I am using bloc for statemanagement and also migrated to yield to emit.
Piece of code is like:
void listenOnMessageReceived(
HubConnection hubConnection,
Function(Message? chatMessageReceive) onMessageReceived,
) {
final SocketResponseCallBack chatMessageReceived =
(response) => onMessageReceived(Message.fromJson(response));
final hubMethod = HubMethod(
CHAT_RECEIVED_MESSAGE_METHOD_NAME,
SignalRHelper.toSocketFunction(
CHAT_RECEIVED_MESSAGE_METHOD_NAME, chatMessageReceived));
bool exists = listenOnHubMethod.any((method) => method.methodName == CHAT_RECEIVED_MESSAGE_METHOD_NAME);
if(exists) {
listenOnHubMethod.removeWhere((element) =>
element.methodName == CHAT_RECEIVED_MESSAGE_METHOD_NAME);
SignalRHelper(hubConnection: hubConnection).on(
hubMethod.methodName,
hubMethod.methodFunction,
);
listenOnHubMethod.add(hubMethod);
}else{
SignalRHelper(hubConnection: hubConnection).on(
hubMethod.methodName,
hubMethod.methodFunction,
);
listenOnHubMethod.add(hubMethod);
}
}
I am having 2 types of above code in different screens. but it is working in only 1 screen and not listening in 2nd screen.
here is a piece of signalr listener code:
static MethodInvocationFunc toSocketFunction(
String methodName, SocketResponseCallBack responseCallBack) {
return (arguments) {
try {
if (arguments!.isEmpty) {
throw SocketEmptyResponseException(methodName);
}
final response = arguments.first;
responseCallBack(response);
} on FormatException {
throw SocketResponseException(methodName);
}
};
}
Is there any limitations in migration of stable version or anything else. Every help is appreciable.
Thank you.
Do not use signalR, on IOS it will be impossible to run listener on background or when app is closed and you will miss messages. Use FCM.

can't load iap products in local, it waits forever

I'm using the official in_app_purchase plugin, version ^1.0.4, and I'm following the official guide from Google insert my first iap (https://codelabs.developers.google.com/codelabs/flutter-in-app-purchases#0).
My consumable iap product is active on Play console with name "pacchetto_25", I've already submitted to the alpha channel my app and is accepted, the tester email is correctly configured in the Tester Group and in Licence Testing.
Now I'm trying to load the iap products in my app, the code is the same of the guide:
Future<void> loadPurchases() async {
final available = await _iap.isAvailable();
if (!available) {
print("STORE NOT AVAILABLE");
return;
} else {
print("STORE AVAILABLE");
const ids = <String>{
"pacchetto_25",
};
final response = await _iap.queryProductDetails(ids);
response.notFoundIDs.forEach((element) {
print('Purchase $element not found');
});
response.productDetails.forEach((element) {
print("Purchase $element found");
});
// products =
// response.productDetails.map((e) => PurchasableProduct(e)).toList();
}
}
In my console I have the "STORE AVAILABLE" message, but then nothing else. If I put same debug point it does not stops on them, this problem appear after this line:
final response = await _iap.queryProductDetails(ids);
Do someone know what's happening? I've no errors in my console and the code after loadPurchases() is not executed, it's like is waiting forever... Any ideas?
Solved! If you have the same issue DON'T put
implementation("com.android.billingclient:billing:4.0.0")
in your build.gradle

Flutter getting an exception when calling queryPastPurchases (in_app_purchase plugin): Cannot find receipt for the current main bundle

I'm trying to utilise the in_app_purchase plugin (https://pub.dev/packages/in_app_purchase) for my Flutter App.
Calling a queryProductDetails(ids) works just fine,
but when calling the queryPastPurchases() I get the following exception:
PlatformException (PlatformException(storekit_no_receipt, Cannot find receipt for the current main bundle., null))
Seems like this is the source for the exception:
https://github.com/flutter/plugins/blob/master/packages/in_app_purchase/ios/Classes/FIAPReceiptManager.m
Worth mentioning:
I've setup an IAP in App-Store-Connect.
This IAP hasn't been sent for Apple approval yet.
App is in development, tested using TestFlight with beta testers.
Another issue is that this exception doesn't get cought in the try-catch statement (see code below), but only by the environment when checking the "All Exceptions" option in VSCode...
Tested on Emulator and real device.
[UPDATE]:
Added a breakpoint to the objective-c code of the plugin, and saw that the receiptURL refers to "sandboxReceipt". So maybe it's because I don't use sandbox users?
Future<void> _getPastPurchases() async {
try {
final QueryPurchaseDetailsResponse response = await InAppPurchaseConnection.instance.queryPastPurchases();
if (response.error != null) {
// Handle the error
print(response.error.toString());
}
print('response = ' + response.toString());
for (PurchaseDetails purchase in response.pastPurchases) {
if (Platform.isIOS) {
//InAppPurchaseConnection.instance.completePurchase(purchase);
}
}
setState(() {
_purchases = response.pastPurchases;
});
} on PlatformException catch(err) {
print(err.toString());
}
catch (err) {
print(err.toString());
}
}

in_app_purchases using flutter

I am trying to create an application that can handle In App Purchases Using Flutter.I am using the in_app_purchase 0.2.1 plugin .I have managed to setup my product on google play developer console as required but however when try to retrieve it from the application i am able to connect to the store successfully but i am not able to retrieve my product ,it always shows up as product not found.
I have followed a this tutorial https://joebirch.co/2019/05/31/adding-in-app-purchases-to-flutter-apps/ and also looked at the package documentation https://pub.dev/packages/in_app_purchase.
My google play setup for the product is shown below
google play console setup
google play console setup2
The function i am using is shown below.
Future<List<ProductDetails>> retrieveProducts() async {
final bool available = await InAppPurchaseConnection.instance.isAvailable();
if (!available) {
// Handle store not available
print("Store Temporarily Unavailable");
return null;
} else {
print("Store Temporarily Available");
const Set<String> _kIds = {'airtime123'};
final ProductDetailsResponse response =
await InAppPurchaseConnection.instance.queryProductDetails(_kIds);
if (response.notFoundIDs.isNotEmpty) {
print("product not found");
print(response.notFoundIDs[0]);
return null;
}
print("product found");
return response.productDetails;
}
}
This is the result i get
I/flutter ( 7254): Store Temporarily Available
I/flutter ( 7254): product not found
I/flutter ( 7254): airtime123
You need to use a reserved SKU for the test: android.test.purchased
const Set<String> _kIds = {'android.test.purchased'};
final ProductDetailsResponse response =
await InAppPurchaseConnection.instance.queryProductDetails(_kIds);