Add observer for tab title

Author: Jose Falcon

.gitignore

@@ -1,2 +1,3 @@
 node_modules/
 src/
+npm-debug.log

javascript/events.js

@@ -12,3 +12,8 @@ chrome.tabs.onUpdated.addListener((tabId, changeInfo, tab) => {
 chrome.tabs.onRemoved.addListener(tabId => {
   dispatch({type: REMOVE_TAB, tabId: tabId});
 })
+
+chrome.runtime.onMessage.addListener((message, sender, sendResponse) => {
+  console.log(message, sender);
+  if (message && message.title) dispatch({type: UPDATE_TAB, tab: sender.tab});
+});

javascript/store.js

@@ -29,16 +29,25 @@ function match(url) {
 }
 
 function updateTab(tab) {
-  let key = match(tab.url);
-  if (key) {
+  let handler = match(tab.url);
+  if (handler) {
     get()
       .then(state => {
         if (!state.tabs) {
           state.tabs = {};
         }
 
-        tab.handler = key;
-        state.tabs[tab.id] = tab;
+        // start tracking the tab. and add a title observer.
+        if (!state.tabs.hasOwnProperty(tab.id)) {
+          chrome.tabs.executeScript(tab.id, {file: 'src/title-observer.js'});
+        }
+
+        state.tabs[tab.id] = {
+          id: tab.id,
+          uri: tab.uri,
+          title: tab.title,
+          handler: handler
+        }
         return save(state);
       });
   } else {

javascript/title-observer.js

@@ -0,0 +1,14 @@
+function notify(title) {
+  try {
+    chrome.runtime.sendMessage({'title': title});
+  } catch(e) {
+    observer.disconnect();
+  }
+}
+
+let observer = new window.MutationObserver(mutations => {
+  mutations.forEach(mutation => notify(mutation.target.textContent));
+});
+
+let target = document.querySelector('head > title');
+observer.observe(target, { subtree: true, characterData: true, childList: true });

package.json

@@ -5,8 +5,8 @@
   "main": "index.js",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1",
-    "js": "browserify javascript/app.js -t babelify --outfile src/app.js && browserify javascript/events.js -t babelify --outfile src/events.js",
-    "clean": "rm src/app.js src/events.js"
+    "js": "browserify javascript/app.js -t babelify --outfile src/app.js && browserify javascript/events.js -t babelify --outfile src/events.js && browserify javascript/title-observer.js -t babelify --outfile src/title-observer.js",
+    "clean": "rm -rf src/"
   },
   "author": "",
   "license": "ISC",