after an extensive search I still can't find a solution to my problem:
I need a Broadcast that runs once a day, no matter if the App is running or not. However, IF the App is running, I also need to update the UI at the end of/after the Broadcast.
I can't use a programmatically registered Broadcast because it ends with the Apps lifecycle. But from a static manifest-registered Broadcast I can't access the UI (at-least I don't know HOW).
One option would be to have 2 different Broadcasts and cancel/start them in onPause and onResume, but I wonder if there is an easier solution?
The thing you need is not broadcast receiver along with AlarmManager or JobScheduler for api above 21 and greenrobot event bus.
AlarmManager Schedules the broadcast call once a day or at any time you want and every time if the broadcast is called you can trigger event from eventbus and receive that event in the place where you want it. The thing why to use event bus is we do not need to handle if the view is visible or not.iF the view is in re use state it triggers the event the view and one method is called by event bus and in that method you can do anything you want to do with view.
personally i don't prefer service because service execution is really expensive now a days.
Note: the package name where you put alarm manager and broadcast
receiver should be "alert" some samsung mobile are very optimized so
they will only let the package name with "alert to run fully". You
will also need on boot receiver to register receiver and schedule
alarmmanager in case if the phone is booted.
Related
I have to schedule an event in Android. My event is starting a service and just doing the work in background even when the application is not running.
Can I do this even without Broadcast Receiver?
For starting the service, do I need Broadcast Receiver?
I saw some posts, only some of them used Broadcast Receiver :
How to start Service using Alarm Manager in Android?
Scheduling an event in Android
http://www.learn-android-easily.com/2013/05/android-alarm-manager_31.html
http://justcallmebrian.com/2010/04/27/using-alarmmanager-to-schedule-activities-on-android/
UPDATE:
From the posts that I read further, I realize that I have to use Broadcast Receiver if the app is not running at the time of event, but I don't need Broadcast Receiver if my application is running at the time of event. Please let me know if I have reached the right conclusion.
You can use JobScheduler to achieve your requirements .
Im confused with Service and Broadcast receiver.what is the relationship between these two?why we have to call broadcast receiver when we start a service.Can anyone kindly explain the concept between these two elements
You don't have to register a BroadcastRecevier when you start a Service. That is, even if you don't register a BroadcastReceiver, our Service will work as expected. There is no must have dependency between the two.
As explained by Gridtestmail, a Service is a process you want to run in the background, without having an interface to the user.
A BroadcastReceiver is registered, when you want to be notified about certain events happening - for example, discovering a new bluetooth device or receiving an incoming call.
If you register a BroadcastReceiver for receiving incoming calls , then your Receiver's onReceive() method is called whenever there is an incoming all, so you can process it.
Similarly, for other event detection stuff.
I hope the concept is clear to you now.
Service: If you want to do something in background , this will be running always in background even if the application closed. You can create this in separate process and also you can give your service to other app if you want. Downloading any content or Music is good example
Broadcast Reciever: Usually system will send some info which can be recieved by your app if you would wish to ,by registering. And you can do something what you want when that thing happens by using onReceive method. Example is the system will send BroadcastReceiver when new sms arrives or Booting done
Example : Service and BroadcastReceiver
ok I have this application which needs to send periodic updates to a web-service, I have done a fair amount of research and I've come up with two service implementation patterns.
Implement a service with a thread, the periodic update time may vary therefore, I will put the thread to sleep with the required time-interval, then call the web-service again. I also need to update an activity, therefore will be using a broadcast receiver or a messenger.
Use a Service with a schedule timer/alarm manager, wake the system and use intent services coupled with a broadcast receiver.
Which would be the best approach?
I think I would go with the #2 option :
Create an IntentService to do the update.
Register a BroadcastReceiver with IntentFilter(s) and start the IntentService from it.
Use AlarmManager to Broadcast the registered action at the required time intervals.
I prefer this method because :
It is a very flexible pattern : You can start the service anytime by registering the same receiver for different actions like network connection changes, system boot changes etc.,
It keeps the logic loosely coupled from other parts of the app.
There is no hassle of managing threads. You get it for free by using IntentService
It is more android-ish way of solving this problem.
The main difference would be that a background service can be shut down by the user and then you won't get any more updates. If you register events with the AlarmManager, then you control when/if these events take place. If the user shuts down your app and goes into a task manager and shuts down any running services related to your app, the AlarmManager is still going to wake up and send a message that your BroadcastReceiver will receive.
I want to create Event Reminder App, I search and found that I need to use a service and broadcast receiver.
But it is not clear for me what is the role of each components ?
As I understand-but I am not sure- that the App needs an Activity that when starts, it runs the service ( which check the current time with times are stored persistently , for example in database !). when the two times match , the service create a broadcast, and our broadcast receiver receives it and create Alert.
My questions are:
Does this inception is correct ?
How to make the service running and always check the time ( do we need some infinite loop?!!)
thanks in advance,
Activities and Services can be killed off without notice anytime system decides it's low on resources. There is no guarantee that your Service would run all the time. Also, if phone is in sleep mode, your code stops executing.
So:
The premise is wrong, for the reasons stated above.
You cant guarantee that Service would be running all the time.
For your purpose you should be using AlarmManager. It is garanteed to call your code when alarm is triggered. Also important - AlarmManager survives device restarts.
I see all the examples of AlarmManager being set by an Activity.
My question is this:
If my application sets a recurring AlarmManager, does that persist even after the application that started is is closed and removed from memory?
If not, how do I start an AlarmManager at a lower level that is started by Android at boot up and if it ever fails or dies or throws an exception is restarted without the user having to do anything?
Lastly, if the action I wish for the BroadcastReceiver to undertake has no visual components, do I still have to create a separate Activity for it? In my case I want there to be a background uploader that wakes up and looks into a folder and if it sees files in that folder, sends them off to the server. I don't need any feedback to the user.
So, my ideal would be to have a magical, OS based AlarmManager that calls an IntentService which just handles the uploading, but I'm unclear on how to get such an AlarmManager running in the first place.
TIA
Yes, AFAIK the alarms "survive" and keeps getting triggered, even after the activity that registered them ends. But they don't survive a phone reboot.
If I understands your problem correctly, I think you can achieve what your looking for by creating a project with a broadcast receiver that listens for android.intent.action.BOOT_COMPLETED intents and then (re-)register a repeating alarm, which in turns starts a (Intent)Service to do the uploading.
You don't need an activity, but you probably would want one anyway, to let the user temporarily disable the upload mechanism by checking off a checkbox, or something. It would probably also be nice to let the user choose the frequency of your alarm, i.e. how often the service should be started and look for new files to upload. This would also be a good place to register your alarm for the first time.
I agree with Nicolai that you'd have 2 broadcast receivers in your application :
one that re-register the alarm on boot
one that starts your service when triggered by the alarm
You could still have an activity but it shouldn't be started by the alarm receiver (hence the service) : instead, maybe launch a notification as you start your service, with the user having the possibility to launch the activity from the expanded message of the notification.
maybe also think about setInexactRepeating (instead of setRepeating) for your alarm, as well as using a worker thread to handle the long uploads (in case the user wants to use your activity in the main thread at the same time).