I once wrote a quick ‘offline.html‘. Just be be sure I understood how offline PWA worked:
This is offline.html (My App Name)
I thought it worked as expected. So I deleted it and wrote a better one, with a back button, some info etc.
Now when this app is offline it starts on the page the manifest.json days, as expected.
However, if I try to refresh the page that spooky "offline.html" shows up. From nowhere.
I've tried to understand where it lurks, but I can't find it. (The new "offline.htmi" is there when I go to it in the web browser.)
I've tried Firefox offline on my mobile to see if the spoky "offline.html" jumps up there to. It does. 😐
I've cleared the cache in Chrome. The spoky "offline.html" is still there.
Any ideas?
(This is on Android 9)
Offline pages are not exactly stored in caches as regular cached items, there are stored quite differently, relative to the current installed service worker. I tried looking for an article to explain this more but can't walk around any currently.
However you'll have to unregister your service worker or learn how Updating service worker works,
The aim is to remove the lurking offline.html served to the new offline.html that exists.
This is what I finally landed on. It seems to work. The test for 404 is of course not optimal, but I leave it that way for now, hoping that the emerging standard will address this issue soon.
async function setupServiceWorker() {
let reg;
if (navigator.serviceWorker.controller) {
console.log("Active service worker found, no need to register");
// new Popup("registered service worker, .active.scriptURL", reg.active.scriptURL, null, true).show();
reg = await navigator.serviceWorker.getRegistration();
} else {
reg = await navigator.serviceWorker.register("service-worker.js", { scope: "./" });
console.log("Service-worker.js registered, scope: " + reg.scope);
}
try {
if (navigator.onLine) {
const newReg = await reg.update();
}
} catch (err) {
const is404 = err.message.match("404");
new Popup("err", is404 + " " + err.message).show();
if (is404) {
let wasUnregistered;
try {
wasUnregistered = await reg.unregister();
} catch (errUnreg) {
new Popup("unregister() service worker failed", errUnreg.message).show();
}
if (wasUnregistered) {
setTimeout(setupServiceWorker, 1000);
}
}
}
}
setTimeout(setupServiceWorker, 5000);
Related
I have an android app with Azure Mobile Services and implemented Offline Sync. The app works well but when syncing data it seems not to complete so there is always a few rows on tables which have not synced?
Anyone have any ideas what the problem might be. I believe that on the next try it would finish where it left off or am I wrong?
Thanks in advance
The app works well but when syncing data it seems not to complete so there is always a few rows on tables which have not synced?
I would recommend you use fiddler to capture the network traces when handling the sync operations.
For Incremental Sync, the request would be as follows:
Get https://{your-app-name}.azurewebsites.net/tables/TodoItem?$filter=(updatedAt%20ge%20datetimeoffset'2017-11-03T06%3A56%3A44.4590000%2B00%3A00')&$orderby=updatedAt&$skip=0&$top=50&__includeDeleted=true
For opting out of incremental sync, you would retrieve all records without the filter updatedAt.
Get https://{your-app-name}.azurewebsites.net/tables/TodoItem?$skip=0&$top=50&__includeDeleted=true
Note: If there are too many items, the SDK would send multiple requests to pull all items that match your given query from the associated remote table. Also, you need to make sure you specify the includeDeleted() in your query.
In summary, you need to make sure that all items could be retrieved via the above requests. Additionally, if the pull operation has pending local updates, then the pull operation would first execute a push operation. So, I assume that you could catch the exception when calling pull operation for handling the conflict resolution.
Bruce's answer is fine but I used a slightly different method without the need to use fiddler.
I change my connection from this
mClient = new MobileServiceClient("[AZUREWEBSITE]", cntxall);
mClient.setAndroidHttpClientFactory(new MyOkHttpClientFactory());
To this
mClient = new MobileServiceClient("[AZUREWEBSITE]", cntxall).withFilter(
new ServiceFilter() {
#Override
public ListenableFuture<ServiceFilterResponse> handleRequest(ServiceFilterRequest request, NextServiceFilterCallback nextServiceFilter) {
// Get the request contents
String url = request.getUrl();
String content = request.getContent();
if (url != null) {
Log.d("Request URL:", url);
}
if (content != null) {
Log.d("Request Content:", content);
}
// Execute the next service filter in the chain
ListenableFuture<ServiceFilterResponse> responseFuture = nextServiceFilter.onNext(request);
Futures.addCallback(responseFuture, new FutureCallback<ServiceFilterResponse>() {
#Override
public void onFailure(Throwable e) {
Log.d("Exception:", e.getMessage());
}
#Override
public void onSuccess(ServiceFilterResponse response) {
if (response != null && response.getContent() != null) {
Log.d("Response Content:", response.getContent());
}
}
});
return responseFuture;
}
}
);
This is the logging method for Azure connections and shows the request in the log.
i am building my app on android repository by Fernando Cejas and i have a problem with subscribing to observable after calling dispose.
When i come to dashboard, i call method subscribeOnUserMessages.execute(new Subscriber(), new Params(token)), which is method in UseCase class
public void execute(DisposableObserver<T> observer, Params params) {
Preconditions.checkNotNull(observer);
final Observable<T> observable = this.buildUseCaseObservable(params)
.subscribeOn(Schedulers.from(threadExecutor))
.observeOn(postExecutionThread.getScheduler());
addDisposable(observable.subscribeWith(observer));
}
In child class SubscribeOnUserMessages i simply call repository like this
return messageRepository.subscribeOnUserMessages(params);
In my socket implementation i create like this
return Observable.create(emitter -> {
if (!isThereInternetConnection()) {
Timber.w("Network connection exception");
emitter.onError(new NetworkConnectionException());
return;
}
/*
* Open socket if not opened
*/
openSocket(params.getToken());
String channelName = CHANNEL_PRIVATE_USER + params.getAuthenticated().getUuid();
if (subscribedChannels.contains(channelName)) {
Timber.d("Channel %s is already subscribed", channelName);
return;
}
JSONObject auth;
try {
auth = createAuthJson(CHANNEL, channelName, params.getToken());
} catch (JSONException e) {
Timber.e("Couldn't create auth json");
emitter.onError(e);
return;
}
mSocket.emit(SUBSCRIBE, auth);
Timber.d("Emitted subscribe with channel: %s ", CHANNEL_PRIVATE_USER + params.getAuthenticated().getUuid());
subscribedChannels.add(CHANNEL_PRIVATE_USER + params.getAuthenticated().getUuid());
Timber.d("Subscribing on event: %s\n with user: %s", EVENT_USER_NEW_MESSAGE, params.getAuthenticated().getUuid());
if (mSocket.hasListeners(EVENT_USER_NEW_MESSAGE)) {
Timber.v("Socket already has listener on event: %s", EVENT_USER_NEW_MESSAGE);
return;
}
mSocket.on(EVENT_USER_NEW_MESSAGE, args -> {
if (args[1] == null) {
emitter.onError(new EmptyResponseException());
}
Timber.d("Event - %s %s", EVENT_USER_NEW_MESSAGE, args[1].toString());
try {
MessageEntity messageEntity = messageEntityJsonMapper.transform(args[1]);
emitter.onNext(messageEntity);
} catch (JSONException e) {
Timber.e(e, "Could not parse message json");
emitter.onError(e);
}
});
});
Symptoms are that first time i subscribe everything is going through to presentation layer. When i dispose after going to second screen and come back i only see logs coming to socket implementation, but not going through.
My question is: Is there a method for subscribing to same observable again? I've already tried to save that observable in my use case in singleton and subscribe to that observable, didn't help.
Without additional info and details regrading socket implementation it is hard to spot the problem exactly, but, from the code you've posted, you don't have dispose logic, so while you might properly call dispose() to the Observable at the correct lifecycle event, your socket will actually stay open, and it might not got disconnected/closed properly ever.
That might lead to a problems opening and connecting to the socket at the 2nd time, as you might try to reopen already open socket and depends on your internal socket impl that might be a problem.
(I can see in the comment that openSocket if not already opened, but still there might be problem elsewhere calling some method on the socket multiple times or setting listeners, again depends on the socket impl)
As a general guidelines, you should add dispose logic using emitter.setCancellable()/emitter.setDisposable() in order to dispose properly the socket resources when you no longer need them, thus - when applying subscribe again (whether the same object or not) will invoke your subscription logic again that will reopen the socket and listen to it.
It is not clear to me if you like to keep the socket open when you moving to a different screen (I don't think it is a good practice, as you will keep this resource open and might never get back to the screen again to use it), but if that's the case as #Phoenix Wang mentioned, you can use publish kind operators to multicast the Observable, so every new Subscriber will not try to reopen the socket (i.e. invoking the subscription logic) but will just get notify about messages running in the already opened socket.
I created a simple app using Meteor 1.3, which has only one method. It works like that: When a button is clicked, the method is invoked - it calculates a specific value and returns the result.
The app works perfectly on the localhost server, but when I launch it on my device with "meteor run android-device", it cannot access the method (simply opens the app, but nothing happens when I press a button.
Do you know how I could resolve this?
import { Template } from 'meteor/templating';
import { ReactiveVar } from 'meteor/reactive-var';
import { ReactiveDict } from 'meteor/reactive-dict';
import './main.html';
Template.check.onCreated(function checkOnCreated() {
this.state = new ReactiveDict();
});
Template.check.events({
'click .checkit'(event, instance) {
Meteor.call('code.check', function(error, result){
if(error){
console.log('Error from the client side!');
} else {
instance.state.set('fett', result.titles[0]);
}
});
},
});
Template.check.helpers({
fett() {
const instance = Template.instance();
if (instance.state.get('fett')) {
return instance.state.get('fett');
} else {
return 'Value still not known...'
}
},
});
Ensure your smartphone's WiFi is turned on and it connected to the same WiFi network as you computer where meteor app is running. Then everything should work fine.
Also, I recommend to use chrome://inspect feature (more info here) in order to debug your app on Android. Then, you will be able quickly investigate any problems with mobile app.
Friends!
I'm getting occasional and unexpected HTTP 400 responses from nanohttpd in my Android app. The error is following a specific pattern. I've been looking at this for some time now but I've come to the point where I need a different angle or some other help pointing me in the right direction.
Could you please have a look and share your thoughts or even direct points and suggestions?
Why am I getting this HTTP 400 status code?
And why only under the given circumstances? (I don't want it at all!)
Some Background
I'm running nanohttpd in my Android project as a temporary isolation layer (due to server side not being mature enough yet). I have isolated the nanohttpd server in an Android Service, which I start from my custom Application object once it's created. This way nanohttpd is not bound to the lifecycle of any particular Activity but can live rather independent of the overall application logic and component life cycles.
The Problem
Now, (almost) everything is working nice and dandy: I can start nanohttpd and perform some initial login requests, my expected mock response is even delivered. When I perform my first "GET" request, though, nanohttpd throws a 400 Bad request status at me, but only the first time. If I back out of the Activity being responsible for the particular "GET" request, and launch it again (from the home screen), it delivers the expected payload with a 200 status, flawlessly.
What Have I Done So Far
I have had a closer look at the nanohttpd source code, trying to track down where and why this 400 status is set. It's not that many places this status code is used. Roughly speaking only here, here and here. Since I'm not dealing with multipart content, I'm left with the first and third "here". But - of course - I can not for my life find neither the root cause of the 400 status, nor which exact block is causing the state for me. When I debug the code, everything works just peachy.
Some Code
This is roughly what my nanohttpd Service (MyNanoHttpdService) looks like:
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
if (ACTION_START.equals(intent.getAction())) {
String errorMessage = null;
if (myNanoHttpd == null) {
String hostUrl = intent.getStringExtra(EXTRA_HOST);
Uri uri = Utils.notEmpty(hostUrl) ? Uri.parse(hostUrl) : Uri.EMPTY;
myNanoHttpd = new MyNanoHttpd(this, uri.getHost(), uri.getPort(), null);
}
if (!myNanoHttpd.isAlive()) {
try {
myNanoHttpd.start();
} catch (IOException e) {
StringWriter stringWriter = new StringWriter();
PrintWriter printWriter = new PrintWriter(stringWriter);
e.printStackTrace(printWriter);
errorMessage = stringWriter.toString();
stopSelf();
}
}
final ResultReceiver resultReceiver = intent.getParcelableExtra(EXTRA_RESULT_LISTENER);
if (resultReceiver != null) {
int status = myNanoHttpd.isAlive() ? CODE_SUCCESS : CODE_FAILURE;
Bundle bundle = new Bundle();
bundle.putString(EXTRA_MESSAGE, errorMessage);
resultReceiver.send(status, bundle);
}
}
return Service.START_STICKY;
}
And this is how I start the service from my custom Application object, initialize my client side state and fetch some content:
#Override
public void onCreate() {
super.onCreate();
// Yes, that is a Java 8 Lambda you see there!
MyNanoHttpdService
.start(this, "http://localhost:8080")
.withStartupListener((status, message) -> {
if (status == 0) {
// POST REQUEST: Works like a charm
myNetworkHelper.login();
// GET REQUEST: Always fails on first launch
myNetworkHelper.getContent();
} else {
Log.e("LOG_TAG", "Couldn't start MyNanoHttpd: " + message);
}
});
}
It's safe to assume that the wrapping convenience code (the .withStartupListener(...) - which essentially wraps a ResultReceiver used by the above Service - and the myNetworkHelper object) works as expected. Also, in production, the getContent() call would be made from an Activity or Fragment, but for the sake ease I have moved it to the Application for now.
I may have found the root cause for my issue, and possibly even a workaround for the moment.
If I'm correct in my investigation, the issue was caused by unconsumed data from a previous (POST) request, contaminating the current (POST) request.
This line in the NanoHTTPD code base (the header parsing block in the NanoHTTPD.HTTPSession.execute() method, just before calling through to any custom serve(...) method - the third "here" in my question above) was the very line where the HTTP 400 status code was thrown, and just as the code suggests, there was no proper value for the "method" header.
The value - which I expected to be "POST" in clear text - was contaminated with parts of the JSON content body from the previous request. As soon as I realized this, I tried to consume the entire request body in my custom MyNanoHttpd.serve(IHTTPSession session) method, like so:
#Override
public Response serve(IHTTPSesion session) {
InputStream inputStream = session.getInputStream();
inputStream.skip(inputStream.available());
// or
// inputStream.skip(Long.MAX_VALUE);
// or even
// inputStream.close();
...
}
This didn't work, though, as I kept getting various exceptions. I ended up gently modifying the NanoHTTPD code, safely closing the input stream in the finally block of the very NanoHTTPD.HTTPSession.execute() method instead.
I'm, nonetheless, considering reaching out to the NanoHTTPD community to discuss a suitable and sustainable solution.
I have a networkStateReceiver, that checks if I have internet or not.
If I do, I reinitiate instabug, if not, I want to deactivate. How can I do that?
I tried just setting it as null, but it doesn't work.
if(haveConnectedMobile || haveConnectedWifi){
//TODO will need to make a queue, and go through all that queue
PSLocationCenter.getInstance().initInstabug();
}else{
PSLocationCenter.getInstance().instabug = null;
}
This is my init:
public void initInstabug() {
String[] feedbackArray = getResources().getStringArray(R.array.feedback);
String randomStr = feedbackArray[new Random().nextInt(feedbackArray.length)];
Instabug.DEBUG = true;
instabug = Instabug.initialize(this)
.setAnnotationActivityClass(InstabugAnnotationActivity.class)
.setShowIntroDialog(true, PSTimelineActivity.class)
.enableEmailField(true, false)
.setEnableOverflowMenuItem(true)
.setDebugEnabled(true)
.setCommentRequired(true)
.setPostFeedbackMessage(randomStr)
.setPostBugReportMessage(randomStr) //TODO will be the post report message, random from array
.setCommentFieldHint("Please describe what went wrong")
.setPreSendingRunnable(new Runnable() {
#Override
public void run() {
String[] files = new String[2];
files[0] = Environment.getExternalStorageDirectory() + "/Passenger/passenger_log.txt";
files[1] = Environment.getExternalStorageDirectory() + "/Passenger/passenger_log2.txt";
Compress compress = new Compress(files, Environment.getExternalStorageDirectory() + "/Passenger/log.zip");
compress.zip(new CrudStateCallback() {
#Override
public void onResponse(String string) {
Log.i("", "ended making the archive");
}
});
}
})
.attachFileAtLocation(Environment.getExternalStorageDirectory() + "/Passenger/log.zip");
}
You can use this code to disable Instabug automatic invocation:
Instabug.getInstance().setInvocationEvent(IBGInvocationEvent.IBGInvocationEventNone)
This way it won't be invoked automatically. This will only affect the next Activity though (not the current one). You may force to stop and restart all listeners by calling onPause and onResume on the current Activity. (We may address that soon though, so that such changes are applied on the currently running Activity).
Don't forget to also enable the shake invocation event when internet access is restored.
Please keep in mind that Instabug SDK already caches all reports and will re-attempt to send them on next app launch until they're uploaded successfully.
Just wanted to post the updated answer.
The newer SDK has changed the name and now you can disable it by the following code:
Instabug.changeInvocationEvent(InstabugInvocationEvent.NONE)
Notice, if you want to disable it for entire application, just call this method in your Application class