devdave · October 16, 2018 20:34 · Dec 2, 2016
diff --git a/background.js b/background.js
@@ -0,0 +1,14 @@
+/*****************************************************************
+ * onMessage from the extension or tab (a content script)
+ *****************************************************************/
+chrome.runtime.onMessage.addListener(
+  function(request, sender, sendResponse) {
+    if (request.cmd == "any command") {
+      sendResponse({ result: "any response from background" });
+    } else {
+      sendResponse({ result: "error", message: `Invalid 'cmd'` });
+    }
+    // Note: Returning true is required here!
+    //  ref: http://stackoverflow.com/questions/20077487/chrome-extension-message-passing-response-not-sent
+    return true; 
+  });
diff --git a/manifest.json b/manifest.json
@@ -0,0 +1,31 @@
+{
+  "name": "example",
+  "version": "0.0.1",
+  "description": "Chrome Extension's message passing example",
+  "permissions": [
+    "<all_urls>",
+    "webRequest",
+    "webRequestBlocking",
+    "background",
+    "activeTab"
+  ],
+  "background": {
+    "scripts": ["background.js"]
+      // "persistent": false
+  },
+  "content_scripts": [{
+    //"matches": ["http://*/*"],
+    // "css": ["mystyles.css"],
+    "js": [
+      "extlib/js/jquery.min.js",
+      "content.js"
+    ]
+  }],
+  "browser_action": {
+    "default_title": "hoge",
+    "default_icon": "icon.png",
+    "default_popup": "popup.html"
+  },
+  "manifest_version": 2,
+  "content_security_policy": "script-src 'self' https://ajax.googleapis.com https://maxcdn.bootstrapcdn.com/; object-src 'self'"
+}
diff --git a/popup.js b/popup.js
@@ -0,0 +1,18 @@
+// If you want to sendMessage from any popup or content script,
+// use `chrome.runtime.sendMessage()`.
+
+// Send message to background:
+chrome.runtime.sendMessage(p, function(response) {
+  console.log(`message from background: ${JSON.stringify(response)}`);
+});
+
+
+// If you want to sendMessage from tab of browser,
+// use `chrome.tabs.sendMessage()`.
+
+// Send message from active tab to background: 
+chrome.tabs.query({ active: true, currentWindow: true }, function(tabs) {
+  chrome.tabs.sendMessage(tabs[0].id, p, function(response) {
+    console.log(`message from background: ${JSON.stringify(response)}`);
+  });
+});