Is there a good example for how to use alarms?

[thirdprize]

I have an app service I want to call at regular intervals. A one off call, once a day for example. I have got it working with alarms but I don't know if I am doing it correctly. I currently have the code shown below which works fine on the emulator but crashes my watch. As I understand it, when my minin program loads it removes any existing alarms (for it) and creates a new one.

The removal part works ok but my watch crashes if i have the set() method call in the code. In this example i want to called every minute (for debugging purposes).

Another things is it takes a few seconds to create the alarm
�6/19 [0]11:44:49.822 I/quickjs-libc SBEngine: creating an alarm for low battery notification
�
�6/19 [0]11:44:56.697 I/quickjs-libc SBEngine: alarm 57 created

import { set, cancel, REPEAT_DAY, REPEAT_HOUR, REPEAT_MINUTE, getAllAlarms } from '@zos/alarm'

App({
  globalData: {},
  onCreate() {
    console.log("low_battery app on create invoke");

    // Remove all existing alarms before adding a new one
    const alarms = getAllAlarms();

    console.log("alarms.length: " + alarms.length);

    if (alarms.length > 0) {
      alarms.forEach(alarm => {
        cancel({ id: alarm });
        console.log(`Removed alarm with id: ${alarm}`);
      });
    }

    console.log("creating an alarm for low battery notification");

    // Set an alarm to trigger every day at 8:00 AM
    const result = set({
      url: "app-service/low_battery_service",
      time: 64800,
      repeat_type: REPEAT_MINUTE,
      store: true
    });
    
     console.log(`alarm ${result} created`);
  },


  onDestroy() {
    console.log("low_battery app on destroy invoke");
  },
});

[SashaCX75]

I'm not sure if the parameter ‘time: 64800’ is correct.
I would also add the parameters repeat_period and repeat_duration.
Here is part of my code where the background service starts every 10 minutes.

        else { // запускаем алярм
          let delay = 5;
          let sec_deley = 60 - timeSensor.getSeconds();
          let min_deley = 10 - timeSensor.getMinutes() % 10 - 1;
          if (min_deley < 0) min_deley += 10;
          delay = 5 + sec_deley + min_deley * 60;
          logger.log(`sec_deley = ${sec_deley}, min_deley = ${min_deley}, delay = ${delay}`);
          // const param = {
          //   battery_service: true
          // }
          const option = {
            url: SERVICE_NAME,
            // param: JSON.stringify(param),
            store: true,
            repeat_type: alarmMgr.REPEAT_MINUTE,
            repeat_period: 10,
            repeat_duration: 1,
            delay: delay,
          };
          let newAlarmId = alarmMgr.set(option);
          logger.log(`newAlarmId = ${newAlarmId}`);
          if (newAlarmId != 0) {
            bat_service = !bat_service;
            setBtnStyle();
          }

        }

[thirdprize]

Thanks. 64800 is 6pm in seconds, the time i want it to run eventually. I dont really understand what the repeat_period and repeat_duration are for. Is it like snoozing an alarm or the duration the alarm occurs for? The documentation is vague.

[SashaCX75]

It seems that the description clearly states that the ‘time’ parameter is the time in UTC. This means that it cannot be such a small number. It was easier for me to set a delay before the start of the event, but you can set the time; it doesn't really matter.

‘repeat_period’ is the time of one cycle. In this case, it is 10 minutes. ‘repeat_duration’ is the number of events during one cycle. In this case, it is one event. At least, that is how I understand it. For my purposes, I always set ‘repeat_duration: 1’. I only changed “repeat_period” and ‘repeat_type’.

[thirdprize]

Silly question, but where do you create your alarm? I set mine in App.onCreate() but I see that gets called multiple times. That is why I delete the alarm and recreate it. Is there another option? Something that gets called once? I suppose I could add the alarm only if the alarms array is empty. I am new to node and JS being a c# dev really.

[SashaCX75]

I never noticed that App.onCreate() is called several times.
But in any case, I don't see the point of putting anything other than reading the initial settings in App.onCreate(). I create an alarm when the application's start page is launched or when the settings are changed. I don't want to create multiple alarms for each event and store their IDs. Therefore, if I need to change the alarm, I simply delete everything and create it again.