NativeScript Firebase already initialized - nativescript

I am using Firebase in my app and I've noticed when I am actively making changes and LiveSync updates the app it will sometimes say "firebase.init error: Firebase already initialized". This happens when the changes don't trigger a whole application restart (ex. an html file). It completely messes up my current authentication state and forces me to restart the app anyways.
Is there some way I can catch for this happening or prevent it? I can try to make a demo app for it, but I feel this might have happened to somebody already.
I am just using the standard firebase.init as shown in the documentation in my app.component, nothing special or different.

Instead of using on ngOnit of App.component, try to initlize firebase on app launch event.
applicationOn(launchEvent, (args: LaunchEventData) => {
firebase.init({
// Optionally pass in properties for database, authentication and cloud messaging,
// see their respective docs.
}).then(
function () {
console.log("firebase.init done");
},
function (error) {
console.log("firebase.init error: " + error);
}
);
});

Related

OneSignal registration fails after refresh

I am using OneSignal in my Laravel/Vue app. I have included it within <head> as stated in documentation:
<script src="https://cdn.onesignal.com/sdks/OneSignalSDK.js" async=""></script>
<script>
var OneSignal = window.OneSignal || [];
OneSignal.push(function() {
OneSignal.init({
appId: "{{ env('ONESIGNAL_APP_ID') }}"
});
OneSignal.showNativePrompt();
});
</script>
<script>
if ('serviceWorker' in navigator) {
navigator.serviceWorker.register('/OneSignalSDKWorker.js')
.then(function () {
console.log('Service worker registered');
})
.catch(function (error) {
console.log('Service worker registration failed:', error);
});
} else {
console.log('Service workers are not supported.');
}
</script>
I also have a service worker of my own, so I've followed the documentation here as well.
What is happening after a hard reset is that service worker gets installed and it is all fine, however once I refresh the page I am getting:
OneSignalPageSDKES6.js?v=151102:1 Uncaught (in promise) InvalidStateError: The current environment does not support this operation.
at Function.getServiceWorkerHref (https://cdn.onesignal.com/sdks/OneSignalPageSDKES6.js?v=151102:1:41510)
at xe. (https://cdn.onesignal.com/sdks/OneSignalPageSDKES6.js?v=151102:1:144028)
at Generator.next ()
at r (https://cdn.onesignal.com/sdks/OneSignalPageSDKES6.js?v=151102:1:716)
And I have no idea what does that mean? What is "current environment"? Where to start debugging? I've tried putting console logs around it, however it led me nowhere...
You would start debugging by looking at the source code of the library.
In your case your library is the OneSignal SDK for browsers.
Let's do this!!!
We can see that this error is thrown by getServiceWorkerHref function (which is defined here) and the error message is driven by the InvalidStateReason enumeration:
case InvalidStateReason.UnsupportedEnvironment:
super(`The current environment does not support this operation.`);
break;
If you look at the first linked file, you will see the note on getServiceWorkerHref OneSignal developers left for the those who dare venture into their source code:
else if (workerState === ServiceWorkerActiveState.Bypassed) {
/*
if the page is hard refreshed bypassing the cache, no service worker
will control the page.
It doesn't matter if we try to reinstall an existing worker; still no
service worker will control the page after installation.
*/
throw new InvalidStateError(InvalidStateReason.UnsupportedEnvironment);
}
As you can see, the error is raised when the service worker has the "Bypassed" state. What is that, you may ask? Let's look at ServiceWorkerActiveState enumeration below, in the same file:
/**
* A service worker is active but not controlling the page. This can occur if
* the page is hard-refreshed bypassing the cache, which also bypasses service
* workers.
*/
Bypassed = 'Bypassed',
It seems, when the browser "hard-refreshes" the page, it bypasses the service worker and OneSignal can't properly initialize when that happens. Hard-refresh can happen for a number of reasons — here are some of them (to the best of my knowledge):
if you click the refresh button a bunch of times (usually seconds consecutive refresh within a short period of time may trigger this)
if you have caching disabled in your DevTools
if the server sets a no-cache header
What is happening after a hard reset
I don't know exactly what you mean by "hard reset", but that sounds like it would trigger this issue. I would suggest you close your browser and then visit the page you are working on without using "reset" functions — theoretically, the service worker should be used for caching on consecutive visits and that would ensure OneSignal can function.

How do I deal with a possible exception in a Xamarin Forms application deployed to iOS or Android?

I have a finished application which I would like to make available to run on the iOS and Android platforms.  I have tested the application as much as possible and it works without problem.  But I know there is always the chance that something might go wrong and I could get an exception.
My question is how can I deal with this or what should I do. What happens on the phone, if a Forms application is deployed and there is an exception.
Would appreciate any advice or even links as to how this is handled.
If an exception is thrown and not handled by your code, the app will stop working (i.e. crash).
In order to handle these crashes we are using MS AppCenter (the successor to HockeyApp/Xamarin AppInsights).
You'll have to create a project there (one for each platform), and add the NuGet package to your projects. Afterwards you can initialize it with
AppCenter.Start("ios={Your App Secret};android={Your App Secret}",
typeof(Crashes)); // you'll get the app secrets from appcenter.ms
Crashes will be logged to AppCenter now and you'll be informed whenever there is a new crash.
Please note that it's best practice (if not required by law), that you ask the user for consent before sending the crash report (see here). You are using the delegate Crashes.ShouldAwaitUserConfirmation for that matter. You could for example show an action sheet with Acr.UserDialogs
private bool AwaitUserConfirmation()
{
// you should of course use your own strings
UserDialogs.Instance.ActionSheet(
new ActionSheetConfig
{
Title = "Oopsie",
Message = "The app crashed. Send crash to developers.",
Options = new List<ActionSheetOption>
{
new ActionSheetOption("Sure", () => Crashes.NotifyUserConfirmation(UserConfirmation.Send)),
new ActionSheetOption("Yepp, and don't bug be again.", () => Crashes.NotifyUserConfirmation(UserConfirmation.AlwaysSend)),
new ActionSheetOption("Nope", () => Crashes.NotifyUserConfirmation(UserConfirmation.DontSend))
}
});
return true;
}

Which event type is triggered when a slack app is installed onto a workspace for the first time?

I'm trying to build an app that does something when it is first installed onto a workspace, eg: Ping every team member.
I couldn't find an event type that gets triggered upon app install:
https://api.slack.com/events
Is there a way to make this happen?
I think there might be a misunderstanding of the events concepts here. Events are always directly linked to one specific Slack app and needs to be processed by that very app. There is no such thing as "general" events for things happening on a workplace, like a new app being installed. Ergo there is no event for app installation.
Nevertheless you can implement the functionality you mentioned with Slack, e.g. pinging all team members once an app is first installed. All you need to do is include this function in the installation process of your Slack app and e.g. start pinging after the installation process is complete and the app verified that it was the first installation to this workspace. You do not need an event for that.
This is a partial answer because I was wondering the same thing and wanted to share what I found. On this oauth tutorial, it has the following code snippet:
app.get('/auth', function(req, res){
if (!req.query.code) { // access denied
return;
}
var data = {form: {
client_id: process.env.SLACK_CLIENT_ID,
client_secret: process.env.SLACK_CLIENT_SECRET,
code: req.query.code
}};
request.post('https://slack.com/api/oauth.access', data, function (error, response, body) {
if (!error && response.statusCode == 200) {
// Get an auth token
let oauthToken = JSON.parse(body).access_token;
// OAuth done- redirect the user to wherever
res.redirect(__dirname + "/public/success.html");
}
})
});
I believe instead of the line res.redirect(__dirname + "/public/success.html"); at that point you can make a request to ping everyone or even call a function to do so directly there, and it will trigger immediately once the app has been installed.

How to natively show the Save Changes Dialog when closing an Electron app?

Im creating an Electron app. I save the user progress in a file. I want the app to show the usual 'Save changes before closing' when the user has not saved and tries to close the App.
I could show a custom dialog, however, I would want to do it the native way.
(Example: On macOS, when you edit a file, the red button changes, letting know the user that the app has unsaved content)
I know this has to be done probably inside the Electron's listener for a closing app:
app.on('window-all-closed', () => {
if (process.platform !== 'darwin') {
app.quit()
}
})
... preventing quit() from being called. And instead handling the unsaved file state and dialog.
PD: I already handle the logic to know whether the user has saved its progress or not. I just want to know how to set the 'Unsaved' state to my electron app and correctly handle it.
(The example is Visual Studio Code, which is also an Electron App)
I usually use a global variable to indicate changes had occured and for example in the case of closing the app:
Code in the main:
mainWindow.on('close', function (event) {
if (global.savetoask== 'Yes') {
event.preventDefault();
//send a ipc message to request a confirm dialog
.............
} else {
app.exit();
}
});

How to prevent app from crashing on uncaughtErrorEvent

Is there a way to prevent the app from crashing when JS uncaught errors occur?
Already tried to wrap app.start(...) inside try/catch, but it sure doesn't work:)
There is indeed, you can register an uncaughtErrorEvent listener.
Refer to the official documentation - https://docs.nativescript.org/core-concepts/application-lifecycle#use-application-events
You can drop the following in your app.js before bootstrapping the application
var application = require("application");
application.on(application.uncaughtErrorEvent, function (args) {
if (args.android) {
// For Android applications, args.android is an NativeScriptError.
console.log("NativeScriptError: " + args.android);
} else if (args.ios) {
// For iOS applications, args.ios is NativeScriptError.
console.log("NativeScriptError: " + args.ios);
}
});
There's no way to prevent the app from crashing. You can catch the error in the uncaughtError application event but the app will crash afterwards regardless.
Attempting to navigate to an error page won't work.
According to the comments on this GitHub issue:
Ability to specify custom error pages on uncaughtErrors · Issue #1718 · NativeScript/NativeScript
there is a way to customize the error page shown, but only on Android. Apparently there isn't anything similar available for iOS.
This is an older question but there is a documented way to prevent this using Nativescript older than 4.2 (you should be on 6+ now)
Disable rethrowing of uncaught js exceptions to native
Basically, catch the JS errors but do not crash the native app.
Note the disclaimer there as well. The script will be unstable at this point. Yes, it did not crash, but wherever it dies did not continue, so you might be worse off for stability. Putting the app in a bad state or just quitting/recrashing might be safer.

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