shared-websocket-component.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">
<link rel="import" href="websocket-component.html">
<link rel="import" href="websocket-sharing-behavior.html">

<!--
A Polymer wrapper for a websocket connection that is shared among certain instances by a ID.

Example:

	<shared-websocket-component socket-id="someID" auto handle-visibility url="wss://echo.websocket.org"></websocket-component>

@element shared-websocket-component
@demo demo/index.html
-->

<dom-module id="shared-websocket-component">
	<template>
		<style>
			:host {
				display: none;
			}
		</style>
	</template>
	<script>
		/**
		* @extends {Polymer.Element}
		* @appliesMixin WebsocketComponentBehavior
		*/
		class SharedWebsocketComponent extends WebsocketSharingBehavior( WebsocketComponentBehavior(Polymer.Element) ) {
			static get is() {
				return "shared-websocket-component";
			}

			static get properties() {
				return {
					_wsReadyFired: {
						type: Boolean,
						value: false
					}
				};
			}

			/**
			* Open the connection manually. May throw errors when already connected or no url is specified.
			*/
			open() {
				if (!this.url || this.url === "") {
					throw new Error("shared-websocket-component(open): no url specified.");
				}
				if (!this.socketId || this.socketId === "") {
					throw new Error("shared-websocket-component(open): no socketId specified.");
				}
				if (this._ws) {
					throw new Error("shared-websocket-component(open): already connected");
				}
				this._ws = this.getOrCreateSocket(this.url, this.protocols);
				this._addEvents();

				if(this.status === 1 && !this._wsReadyFired) {
					this._wsReadyFired = true;
					this.dispatchEvent(new CustomEvent("websocket-ready"));
				}
			}

			/**
			* Close the connection manually. Trows an error when the websocket is not connected.
			*/
			close() {
				if (!this._ws) {
					throw new Error("shared-websocket-component(close): not connected.");
				}
				this._ws.close();
				this._ws = null;
				this.removeWebsocket()
			}

			_onwsopen() {
				super._onwsopen();
				if(!this._wsReadyFired) {
					this._wsReadyFired = true;
					this.dispatchEvent(new CustomEvent("websocket-ready"));
				}
			}

			_onwsclose(event) {
				super._onwsclose(event);
				const removeEvent = (name, callback) => {
					this._ws.removeEventListener(name, callback.bind(this));
				};
				removeEvent("open", this._onwsopen);
				removeEvent("error", this._onwserror);
				removeEvent("message", this._onwsmessage);
				removeEvent("close", this._onwsclose);
			}
		}

		window.customElements.define(SharedWebsocketComponent.is, SharedWebsocketComponent);
	</script>
</dom-module>