I got the question today from Fabian Lenz if it is possible to send messages to end users using the Horizon API. I knew I had seen it somewhere already and here’s a quick explanation.

There are two method’s to do this, one for a single session and the other for a group of sessions. Both fall under the session service.

$services1.session | gm

You can see both the methods called session_sendmessage and session_sendmessages if we look at what’s required for both we see that the difference is a single sessionid or an array of session id’s.

Let’s see what the API explorer says what’s needed.

So the msgtype is a string that can have three values and the message is just a string, let’s test this.

I am lazy and will use get-hvlocalsession for the sessionid.

$session=get-HVlocalsession | select -first 1

I do the -first 1 so it isn’t an array but a single session.

Now let’s send a message.

$services1.session.Session_SendMessage($session.id,"INFO","This is a test message for retouw.nl at 30-10-2018 19:13h")

And the result:

Now let’s do the same for multiple sessions.

$sessions=get-HVlocalsession $services1.session.Session_SendMessages($sessions.id,"ERROR","This is a test message with multiple recipients for retouw.nl at 30-10-2018 19:25h")

And to show that this also works for global sessions (both where connected to pod2cbr1)

$sessions=get-HVglobalsession $services2.session.Session_SendMessages($globalsessions.id,"WARNING","This is a test message with multiple global recipients for retouw.nl at 30-10-2018 19:30h")

If you want to filter the sessions on user or machine name you can filter the $globalsessions on $globalsessions.namesdata.basenames

$globalsessions.namesdata.basenames | select-object username,machineorrdsservername,clientname

With the localsessions it’s located in $sessions.namesdata

$sessions.namesdata | select-object username,machineorrdsservername,clientname

It’s also possible to filter this with the query service, take a look on my previous post on how to handle queries.

So now you know how to send messages to users. Not that they always read these messages but at least you can try warning them a bit faster now!