For one of my Home Assistant automations, I want to send notifications to a couple of Android devices. I also want to be able to update the contents of those notifications when I get new sensor readings, so per the documentation I use a tag to replace the existing notifications.
But there’s one snag that Home Assistant doesn’t support out of the box: if I dismiss (clear) a notification on one of the Android devices, then the next time I try to send an update it will pop up again.
Instead, I want notifications to exist in sort of a session. The session starts the first time the automation sends a notification, and stops when the automation sends a clear_notification message. During the session, new updates to the notification will only be sent to Android devices that haven’t cleared the notification over the course of the session.
Note: this only works for Android devices, since iOS doesn’t report when notifications are cleared by the user.
Complications
To accomplish this I wrote an AppDaemon script which will send notifications and listen for the mobile_app_notification_cleared event to know when a notification has been cleared.
Unfortunately the mobile_app_notification_cleared event doesn’t contain useful information about what device cleared the notification–it contains a DEVICE_ID which is a hexadecimal string, but I can’t find any way to easily map that DEVICE_ID back to the actual string representing the target (i.e. the <your_device_id_here> in the notify.mobile_app_<your_device_id_here> service call).
However, when a notification is cleared the event does contain all the data of the notification–including its tag. Thus, by sending each notification with a unique tag that contains both the name of the AppDaemon app and the name of the specific target, we can distinguish between devices when we get the mobile_app_notification_cleared event.
High level overview
At a high level, the AppDaemon app works as follows:
- Via the app’s YAML configuration you specify the Android devices you want to target, as well as any default data you want to include in every notification. (I.e. the
dataobject that’s at the same level as thetitleormessage.) - The app listens for a specific event,
notify_android_uncleared_<APP_NAME>, where<APP_NAME>is the name of the app in the app’s YAML configuration, and where the event data matches the data you’d send in anotify.mobile_app_<your_device_id_here>service call. - When it first sees the
notify_android_uncleared_<APP_NAME>event, it adds all the target devices to the list of active devices, and sends them all the notification. With every notification, it overwrites thetagfield in the notification’sdata, to the form<APP_NAME>_<your_device_id_here>. - The app also listens for the
mobile_app_notification_clearedevent. If it receives it, it checks to see if thetagin the event’sdatamatches the form<APP_NAME>_<your_device_id_here>. If so, it removes the corresponding device from the list of active devices. - If the app hears the
notify_android_uncleared_<APP_NAME>event again, it only sends the updated notification to targets that are still active. - If the app hears the
notify_android_uncleared_<APP_NAME>event but themessageisclear_notification, then the app sends that message to all the remaining active targets, then sets a flag to indicate the session is over. The next time it hears thenotify_android_uncleared_<APP_NAME>event it starts over at step (2).
The code
All of the code can be found on my blog, including sample YAML for configuring the app and a sample event call for a Home Assistant script/automation.
To use the app, follow the instructions in the AppDaemon documentation. You’ll need to create a new python file named update_uncleared_android_notifications.py, and then drop the AppDaemon YAML in apps.yaml or another YAML config file (and configure it appropriately). Then just fire off the event from Home Assistant like shown on the blog, and you’re all set!