Sakai now has a user messaging service that handles email and browser push. A tool can use this api to send an email or add to a digest. The service also supports a list of user notification handlers to handle events from the event bus (EventTrackingService). User notifications result in a browser push so any browsers that have opted in will receive a push event and that will be displayed in their bullhorn alerts. One user can have many push endpoints, one for each device, and all those will receive a push.
A tool registers email templates, one for each type of email, and uses this api to send a message key and a map with the values to insert into the template. This map would also include the translations needed to internationalise the email.
Push is triggered by Sakai events, and events are only pushed to the browser if a tool has registered a handler for that event. Also, events are only pushed to a browser if the user has accepted those events.
Browser push uses public key encryption to secure the push messages, and the key pair needs to be generated. OOTB, Sakai will generate these for you if they are not in the Sakai home directory already - you still need to specify a subject though. You could allow Sakai to create a keypair on one node and then copy those keys over scp to your other Sakai nodes. If you want to setup your own keys, you will need to generate a [VAPID] (https://datatracker.ietf.org/doc/html/draft-thomson-webpush-vapid) keypair. Fortunately, this is pretty easy - you can use an online generator for these and [here is one] (https://vapidkeys.com/). The email you specify is called the "sub" in the push service call, and you'll need that for your Sakai properties. Once you have your keypair, save them in your sakai home directory, under your Tomcat. The default, but configurable, names for these are sakai_push.key and sakai_push.key.pub. You will need to set your subject email in your Sakai properties.
Once you've configured your push settings, enable push by setting portal.notifications.push.enabled to true, and restart Sakai.
Notifications need to be permitted on the client browser. You know those annoying requests you ignore all the time - you'll see one of those when you click the bullhorns icon. Accept them from Sakai. Or don't - your choice :)
If you want to adapt a tool to consume push events on the client, you will need code something like this in your tool's js. Let's use assignments as an example:
portal.notifications.setup.then(() => {
portal.notifications.registerPushCallback("sakai.assignment.grades", () => {
console.log("Don't ... Push ... Me");
... more code ...
});
});
Assignments does push events. For instance - when you submit an assignment as a student a push event goes out from Sakai to the push service.
Push is currently on by default. To disable it, set this to false.
If you're not happy with the default of sakai_push.key.pub, set it with this property.
If you're not happy with the default of sakai_push.key, set it with this property.
You have to set this. Use the email that you specified when generating your VAPID keypair.