websocket-sharing-behavior.html

<!--
Copyright (c) 2018 Willem Burgers. All rights reserved.
This code may only be used under the BSD style license found at http://wburgers.github.io/LICENSE.txt
For a list of Contributors check https://github.com/wburgers/websocket-component/graphs/contributors
-->
<link rel="import" href="../polymer/polymer.html">
<script>
	/** @polymerBehavior */
	const WebsocketSharingBehavior = subclass => class extends subclass {
		static get properties() {
			return {
				/**
				 * The socketId is the identifier for the shared socket, if a socket with the given identifier exists it
				 * will be used, if not, a new one will be created.
				 */
				socketId: {
					type: String
				},
				/**
				 * a Map of websockets ( identifier -> WebScoket ) that is shared across all instances
				 */
				_websockets: {
					type: Object,
					value: new Map()
				}
			}
		}

		/**
		 * Tries to get an instance of a websocket by the socketId
		 * If it does not exist it creates a new Websocket
		 * @param socketId
		 * @param socketUrl
		 * @param socketProtocols
		 */
		getOrCreateSocket(socketUrl, socketProtocols, _socketId) {
			const socketId = _socketId | this.socketId;
			if (!this._websockets.has(socketId)) {
				this._websockets.set(socketId, new WebSocket(socketUrl, socketProtocols));
			}
			return this._websockets.get(socketId);
		}

		removeWebsocket(_socketId) {
			const socketId = _socketId | this.socketId;
			this._websockets.delete(socketId)
		}
	}
</script>