Checking Room DB table every seconds in Background and display Notification

Question

I am building a scheduling App, I store all scheduled notification inside a Room DB Table, I want to check every second if the current time/date is equal to the DB Table time/date, and it's should display a notification for it.

How can I do this?

Hi , please consider upvoting my answer, i'm trying to get rid of all my zero rated answers :D — a_local_nobody, Aug 04 '19 at 08:26

score 1 · Answer 1 · answered Jul 17 '19 at 08:28

1

Have a look at this SO question here : Repeat a task with a time delay? have a look at Handler's postDelayed feature. get the value from the database you want to check and then use a postDelayed to check if it matches up

answered Jul 17 '19 at 08:28

a_local_nobody

7,947
5
29
51

Can you please help me design code because am not getting it, and am been divert to WorkManager and am still confused. – SilenceCodder Jul 18 '19 at 15:56
I submitted a different answer now, have a look at that @Harbdollar – a_local_nobody Jul 18 '19 at 16:04

score 1 · Answer 2 · answered Jul 17 '19 at 08:42

I think you should use another design pattern to implement it instead of "check every second", but here is a little snippet how it could work:

final LiveData<Integer> id = scheduledRepository.getScheduledItemId(System.currentTimeMillis());
        id.observe(this, new Observer<Integer>() {
            @Override
            public void onChanged(@Nullable Integer integer) {
                if(integer == null){
                    //do nothing
                } else {
                    Toast.makeText(getApplicationContext(), YOUR_NOTIFICATION_TEXT, Toast.LENGTH_LONG).show();
                    id.removeObserver(this);
                    return;
                }
            }
        });

Your DAO will be something like this:

@Query("SELECT id FROM T_SCHEDULER WHERE date = :currentdate")
 LiveData<Integer> getScheduledItemId(long currentdate);

Will I implement this inside a button or what?, because I think the code should be inside a service or background? — SilenceCodder, Jul 17 '19 at 09:08
try to put it in a handler like this: `Handler handler = new Handler(); int delay = 1000; //milliseconds handler.postDelayed(new Runnable(){ public void run(){ //DB action here handler.postDelayed(this, delay); } }, delay);` — Levente Takács, Jul 17 '19 at 09:16

score 0 · Accepted Answer · answered Jul 18 '19 at 16:01

0

Try something like this

Handler handler = new Handler();
int delay = 1000; //milliseconds

handler.postDelayed(new Runnable() {
    public void run() { //DB action here 
        //Todo, here you would put in your DB logic to check if the stuff matches
         handler.postDelayed(this, delay);
    }
}, delay);

answered Jul 18 '19 at 16:01

a_local_nobody

7,947
5
29
51

Am really busy with something else, I just implement it yesterday and it works, but sometimes it works when I minimize the app and also close the entire app. what can I do to achieve this. And also how can I pause it and let it continue when it performed something. – SilenceCodder Jul 22 '19 at 08:43
you would have to look into creating a service for something like that @Harbdollar – a_local_nobody Jul 22 '19 at 10:02
Yea, I know about service, That means I have to add it inside a service, – SilenceCodder Jul 24 '19 at 07:18

Checking Room DB table every seconds in Background and display Notification

3 Answers3