Inter-Button communication API

[buffos]

Motivation

As is now, it is very hard to make inter-button communication.
For example, I want to create an internal OSC server to listen to state changes on buttons and inform them (or web server) etc.

How could it be implemented?

Following the current form of the API, we can add two functions. One to the StreamDeck and one to the Actions class to override:

streamdeck.SendDataTo("keyString", dataObject) and action.Subscribe("keyString",obj, callbackfn)

The form of Subscribe allows adding subscriptions to many keys.

Usage

What this means is that actions will subscribe to these key changes and act if they are interested.
Keys can be URLs, OSC paths, names of applications, or anything else, and inter-button communication is very easy this way.

We could probably simulate that by setting values in global settings with a certain key and then deep linking to notify the action, which will read the global settings key and act accordingly, but this is too error-prone.

This will make it easier to make more general plugins.

For example, I have a service, and I publish new data every n seconds. I create my plugin, you set the interval rate, and the plugin publishes some keys. Any plugin can read and react to the values published.

[tiptronic]

hey @buffos
likely I don't understand the request ( and honestly I don't know what OSC server is), but you can do all of this today using a bunch of ways, e.g:

• using a Proxy
• using Node's EventEmitter
• using a REST-API on your own background-service
• using your own WebsocketServer (if you plan to talk (bi-directionally) to various plugins or even external apps).
• or even MQTT (or whatever) to talk to other machines, IOT etc..

Making this generally available on a plugin basis is likely a call for trouble, because then a plugin relies on (or needs) another plugin to add functionality

[buffos]

Is there any repo with examples of how to do that?
My only source of documentation is streamdeck's official documentation and the 3 examples on GitHub (especially the game example which was great).

Can you please point to plugins using those methods (if it's possible)?

Making this generally available on a plugin basis is likely a call for trouble, because then a plugin relies on (or needs) another plugin to add functionality

This is the downside, of course. The upside is deduplication. You do not have to implement the same functionality in many plugins.
Besides, we still rely on other plugins to accomplish tasks (with multi-actions). The difference is that it is accomplished by inclusion.
What I was suggesting was message-passing inclusion.

multi-actions => cooperation by inclusion
message-passing => cooperation by messages

Thank you in advance for your time.

[tiptronic]

Hi @buffos
there's a bunch of plugins out there which allow remote-connection, e.g.:

https://github.com/ybizeul/StreamDeckWS
e.g. in conjunction with NodeRed:
https://flows.nodered.org/node/node-red-contrib-streamdeck-ws

or with HomeAssistant:
https://github.com/cgiesche/streamdeck-homeassistant

or using MQTT:
https://marketplace.elgato.com/product/mqtt-99faa0b9-7d88-499a-ab4f-6d55f8c2e0a8

Just google for it and you will find many more...

If many plugins want to use the same functionality, then that's a good sign you need a background-service like our very own Volume Controller plugin:
https://marketplace.elgato.com/product/volume-controller-34d9aa59-a41a-4a4c-a853-202ca91409e1

https://www.youtube.com/watch?v=dDIl5CqJwRo

That way all plugins interested in communicaton with the service can install it and talk to it...

btw: Multi-Actions don't rely onto each other, but execute their actions one after another

[tiptronic]

If you want to just pass information from one action to another - you are aleady doing that properly in your sample:
UpdateAllButtonDetails

And if you want to communicate with other Makers, it's much more effective if you join us on discord:

https://discord.gg/StwbM2S9

[buffos]

@tiptronic.

I don't know where you got the snippet,

My question was not what the snippet does. I was hoping to capture custom "events" sent outside Stream Deck, inside the plugin.
Probably this falls under the "WebSocket API", but there are no examples there.

Anyway. I probably wasted a lot of your time. I will try working around that with deep-links.

[tiptronic]

hey @buffos
np - but using deep-links you usually talk from outside Stream Deck to Stream Deck.

If you want to talk (bi-directionally) to an outside service (or background-service or any kind of server, you usually use something like Websockets, Json-RPC, or whatever).

Here's a very quick overview of a websocket connection (this has NOTHING to do with Stream Deck and would also work in any browerer of plain Nodejs:

const host = '127.0.0.1'; // address on your local machine
const port = 8987;  // some port on that address where the server listens on

const websocket = new WebSocket(`ws://${host}:${port}`); // now try to create a websocket connection

websocket.onopen = function() {
    // websocket opened
};

websocket.onclose = function(evt) {
    // websocket was closed
};

websocket.onerror = function(evt) {
    // error
};

websocket.onmessage = function(evt) {
   // message received
};

websocket.send('Hello, Server!');

In the onmessage event-handler you would get all messages from the server, which you then can dispatch to your plugin, action or do anything else inside your plugin.

That's it

[buffos]

@tiptronic

Thank you once again.

np - but using deep-links you usually talk from outside Stream Deck to Stream Deck.

yes. This is exactly what I want. outside Stream Deck initiated communication, not streamdeck initiated communication (which can be done in multiple ways, including ws)

I probably have some wrong assumptions. I thought that:

1. streamdeck internally has an open ws to a random port
2. I could send data directly to that port from outside (but I do not know the port).
3. Receive the data as global settings and then do whatever I want.

So you propose instead to create internally a websocket to a predefined port and connect to the source(s) I want?

[tiptronic]

OK - that's easier to answer:

1 - NO
2 - NO
3 - NO

Last: if you don't want to open a security hole, the proper way would be to create an external service/background task and then connect from your plugin to it. (Much like requesting data using a fetch operation)