Add web component

.gitignore

@@ -7,5 +7,7 @@
 /spec/reports/
 /tmp/
 
+node_modules
+
 # rspec failure tracking
 .rspec_status

web/.npmignore

@@ -0,0 +1,3 @@
+npm-debug.log
+node_modules
+.DS_Store

web/index.js

@@ -0,0 +1,39 @@
+import { connectStreamSource, disconnectStreamSource } from "@hotwired/turbo";
+
+export default class TurboTrain extends HTMLElement {
+  static get observedAttributes() {
+    return [ 'href', 'session', 'name' ];
+  }
+
+  constructor() {
+    super();
+  }
+
+  connectedCallback() {
+    this.eventSource = new EventSource(`${this.href}/mercure?topic=${this.name}&authorization=${this.session}`);
+    connectStreamSource(this.eventSource);
+  }
+
+  disconnectedCallback() {
+    disconnectStreamSource(this.eventSource);
+  }
+
+  get href() {
+    return this.getAttribute('href');
+  }
+
+  get session() {
+    return this.getAttribute('session');
+  }
+
+  get name() {
+    return this.getAttribute('name');
+  }
+}
+
+if (
+  typeof window !== 'undefined' &&
+  !window.customElements.get('turbo-train-stream-source')
+) {
+  window.customElements.define('turbo-train-stream-source', TurboTrain)
+}

web/package.json

@@ -0,0 +1,28 @@
+{
+  "name": "@uscreentv/turbo-train",
+  "version": "0.0.1",
+  "description": "",
+  "main": "index.js",
+  "type": "module",
+  "exports": {
+    ".": {
+      "import": "./index.js"
+    }
+  },
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/Uscreen-video/turbo-train.git"
+  },
+  "author": "",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/Uscreen-video/turbo-train/issues"
+  },
+  "homepage": "https://github.com/Uscreen-video/turbo-train#readme",
+  "peerDependencies": {
+    "@hotwired/turbo": "^7.2.4"
+  }
+}