I Initialize Publish Subject Rx Java in my activity like this
private var publisher = PublishSubject.create<Int>()
And I try to create simple publish onNext like this in a button :
binding.btnFab.setOnClickListener {
publisher.onNext(99)
}
I try to listen the changes in function
CompositeDisposable().add(publisher.ofType(Int::class.java).subscribe(
{
"ON NEXT ${it}"
},
{
"ON ERROR"
},
{
"ON COMPLETE"
}
))
But there is no one data that come out from my subscribe? do i make a mistake
Related
I've got a method called showNotification that shows notification
public static void showNotification(UI ui, String notificationMessage) {
Notification notification = new Notification(notificationMessage);
notification.setStyleName("custom-notification");
notification.show(ui.getPage());
}
And I've got a service that returns CompletableFuture.
In my controller I created method
#Override
public CompletableFuture<?> startProcessing() {
return processorService.start();
}
And on button click I want to show notification if start was successful.
My buttonClick event looks like this
event -> {
controller.startProcessing()
.thenAccept(aVoid -> UI.getCurrent().access(() -> {
showNotification(getUI(), "Started processing");
})
).handle((aVoid, throwable) -> {
showNotification(getUI(), "Failed to start processing");
return aVoid;
});
}
The problem is that until I invoke another event - like for example click on another button - it doesn't show notification.
What is the problem?
You need to add #Push to your UI subclass to make the browser open a two-directional connection with the server. Without that, only the browser can initiate communication, and it only does that when there's some new event to send to the server.
swipeRefreshLayout.setOnRefreshListener(() -> {
swipeRefreshLayout.setRefreshing(true);
retrieveData(mCardAdapter, db);
});
For some reason the following method is blocking my main UI thread, but it should be running in the background. For example, the refresh indicator hangs when I run retrieveData(). If I initialize a progress dialog before running, it also hangs and I can't scroll through my RecyclerView. Am I fundamentally misunderstanding something here?
public void retrieveData(final CardAdapter mCardAdapter, SQLiteHelper db) {
CausticRetrofitService service = ServiceFactory.createRetrofitService(CausticRetrofitService.class, CausticRetrofitService.SERVICE_ENDPOINT);
service.getMedia()
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
.subscribe(new Subscriber < MediaResponse > () {
#Override
public final void onCompleted() {
Log.e("CausticRetrofitService", "Caustic Request Completed!");
/* Cancel all progress indicators after data retrieval complete */
setRefreshingFalse();
// TODO: Add media to local data store and then display them one-by-one in real-time
mCardAdapter.addData(db.getAllMediaImages()); // Add all media images to card views
Log.d(getClass().toString(), "Added to local database: " + db.getAllMediaImages());
mCardAdapter.notifyDataSetChanged();
}
#Override
public final void onError(Throwable e) {
/* Cancel all progress indicators on data retrieval error */
setRefreshingFalse();
Toast.makeText(getApplicationContext(), "Cannot retrieve data. Please try again later.", Toast.LENGTH_SHORT).show();
Log.e("CausticRetrofitService", e.getMessage());
}
#Override
public final void onNext(MediaResponse mediaResponse) {
if (mediaResponse != null) {
Log.e("CausticRetrofitService", "Returned objects: " + mediaResponse.getResults());
for (String mediaId: mediaResponse.getResults()) {
Log.e("CausticRetrofitService", mediaId);
}
List < String > mediaIds = mediaResponse.getResults();
Log.d(getClass().toString(), "All Media IDs: " + mediaIds);
if (mediaIds.isEmpty()) {
Toast.makeText(getApplicationContext(), "Cannot retrieve data. Please try again later.", Toast.LENGTH_SHORT).show();
}
mCardAdapter.clear();
mCardAdapter.notifyDataSetChanged();
/* Store objects from remote web service to local database */
for (String mediaId: mediaIds) {
// TODO: Why are these null?
Log.d(getClass().toString(), "Media Id: " + mediaId);
MediaImage newMediaImage = new MediaImage();
newMediaImage.setTitle(mediaId);
db.addMediaImage(newMediaImage); // Add media image to local database
}
} else {
Log.e("CausticRetrofitService", "Object returned is null.");
}
}
});
}
I'm thinking that adding the remote data to the local data store in the onNext() method might be the thing that's blocking, although I'm not certain.
Your network call is done in a new thread as you specified, but the Subscriber methods onNext() and onComplete() runs on the observing Scheduler, which is the main thread.
You seem to be doing some database operations on those, try to offload the caching also to the background thread using a doOnNext() operator.
What doOnNext() will do, is that it is called for each emission in your stream.
It can go something like that
service.getMedia()
.doOnNext(data -> cacheData(data))
.subscribeOn(Schedulers.newThread())
.observeOn(AndroidSchedulers.mainThread())
Where cacheData() is a method that does all your DB calls. And the only things left in your onNext() and onComplete() would be updating the UI only.
Backend server sends FCM notification like this:
{
"to": "/topics/599_7041",
"priority": "high",
"data": {
"id_message": "45"
}
"click_action": "SHOW"
"notification" : {
"body" : "Lorem ipsum",
"title" : "Sample"
}
}
My application subscribes multiple topics. When application is not running, Firebase displays notification and allows me to run app after tap on notification message, with provided click action and pass data (in this case, message_id) to launched app instance.
Good so far. However, in addition, I need to determine from which subscribed topic notification is received. Can I determine it somehow when launching new app instance from notification, or I need to add topic name to data (next to message_id)?
I know I can determine to filed when my app is running, this way:
#Override
public void onMessageReceived(#NonNull final RemoteMessage remoteMessage)
{
//....
String to = remoteMessage.getTo();
}
But, what if my app is not running, so onMessageReceived won't be called.
you can do this:
exports.pushNotification =
functions.database.ref('/messages/{pushId}').onWrite( event => {
console.log('Push notification event triggered');
var valueObject = event.data.val();
console.log("it is"+ valueObject.title);
//Create a notification
const payload = {
notification: {
title:valueObject.title,
body: valueObject.message,
sound: "default"
},
};
This way you are using the database trigger onWrite, that checks if any messages have been written under the pushid.
Then you retreive the data from the database using: var valueObject = event.data.val();.
And in the notification{..} you can use valueObject.title which will be the topic name, thus when recieving a notification, the topic name will be in the title of the notification and thats how you can know what topic it is.
For more info check https://firebase.google.com/docs/functions/database-events
In Backendless, there is a method from which I can subscribe to a channel and listen for incoming messages.
Backendless.Messaging.subscribe(
channelName, //some random name
500, //500 ms interval for polling
new AsyncCallback<List<com.backendless.messaging.Message>>() {
#Override
public void handleResponse(List<com.backendless.messaging.Message> messages) {
System.out.println("message received on your channel");
}
#Override
public void handleFault(BackendlessFault backendlessFault) {
}
},
new AsyncCallback<Subscription>() {
#Override
public void handleResponse(Subscription subscription) {
System.out.println("You subscribed to channel" + subscription.getChannelName() + " succssesfuly");
}
#Override
public void handleFault(BackendlessFault backendlessFault) {
System.out.println("Error: " + backendlessFault.getMessage());
}
}
);
If it subscribes from the MainActivity, and data was sent while the app is in another Activity, how can it grab the data from the response (the List in the first handleResponse method) and use it in other activities?
Should I use a service? Should I bind activities to this service with the listener?
Or is there any less complicated way to accomplish my need?
In the very near future i want this listener to work when the app is in the background and show a notification to a user.
Backendless uses two types of Messaging, see Publish-Subscribe Messaging & Push Notifications. The first one is implemented using the listener you used above. The second one uses a service. please refer to the docs, although they are not very good at all they do provide the necessary information.
When developing Cordova plugins, all of the tutorials I have found go something like this:
File: AwesomePlugin.js
var AwesomePlugin = {
kungfuGripAction = function(target, successCallback, failureCallback) {
return cordova.exec(
successCallback,
failureCallback,
'AwesomePluginClass',
'kungfuGripAction',
[target]
);
}
};
module.exports = AwesomePlugin;
File: AwesomePluginClass.java
#Override
public boolean execute(String action, JSONArray args, CallbackContext callbackContext) throws JSONException {
if (ACTION_KUNGFU_GRIP.equals(action)) {
JSONObject target = args.getJSONObject(0);
if (gripTarget(target)) {
callbackContext.success("Target successfully gripped.");
return true;
} else {
callbackContext.error("Could not grip target.");
return false;
}
}
Log.d(LOG_TAG, "INVALID ACTION! " + action);
callbackContext.error("Invalid action: " + action);
return false;
}
File: clientCode.js
AwesomePlugin.kungfuGripAction(cobraEnemy, function(ok) { }, function(err) { });
In the above code, the callbacks can only be called once and are then disposed. If you attempt to call the .success() or .error() method of the callback context object, it will not work and you will get a log message:
Attempted to send a second callback for ID: AwesomePlugin2982699494<BR>W/CordovaPlugin(976) Result was: "Target successfully gripped."
It seems like it is not possible to write a method with a callback that can be called repeatedly seeing as .success() and .error() are the only documented ways to invoke a callback from within native plugin code. While this is mostly what we want, there are times when we want to have the plugin execute a callback repeatedly. For example:
AwesomePlugin.kungfuGripAction(cobraEnemy, function(ok) {
// After successful grip, punch repeatedly and update life meter.
AwesomePlugin.punchRepeatedly(cobraEnemy, function(hits) {
updateLifeMeter(cobraEnemy, hits);
}, function(err) { });
}, function(err) { });
AwesomePlugin.punchRepeatedly() above will execute repeatedly (maybe in a separate thread) and call function(hits) with each successful execution. If implemented in the de-facto way (using single-use callbacks), you have to either use a loop (which is bad as it is non-async) or tail-call AwesomePlugin.punchRepeatedly() in the callback (error-prone).
What would be the correct way to implement punchRepeatedly() in native code so that it is able register the callback once and then execute it repeatedly?
I think, you can use a pluginResult with the keepCallback property set to true.
PluginResult result = new PluginResult(PluginResult.Status.OK, "YOUR_MESSAGE");
// PluginResult result = new PluginResult(PluginResult.Status.ERROR, "YOUR_ERROR_MESSAGE");
result.setKeepCallback(true);
callbackContext.sendPluginResult(result);
You should be able to invoke the callback several times this way.
In jonas's answer, every time you call sendPluginResult you have to send the same value. So I changed the PluginResult class to add a method like this:
public void setStrMessage(String strMessage){
this.strMessage = strMessage;
}
This way, I can set the message I want to send to the JavaScript side.