Content script is not executing

Question

I have created Chrome extension which should change page body color. It is working when I am clicking on the extension but I want it be done when the page loads, where an alert shows that controls is passing through code, it is not calling the function. Please help to fix this.

----------manifest.json-----------

{
 "name": "My Page changer",
 "description": "Make the current page red",
 "version": "2.0",
 "permissions": [
 "activeTab"
 ],
 "background": {
 "scripts": ["background.js"],
 "persistent": false
 },
 "browser_action": {
 "default_title": "Make this page blue"
 },
 "manifest_version": 2
}

------------------ background.js--------------------

debugger;
chrome.tabs.onUpdated.addListener(function(tabId, changeInfo, tab) {
 if (changeInfo.status == 'complete') {
 debugger;
 alert('I am here too ');
 /*chrome.tabs.executeScript({
 code: 'document.body.style.backgroundColor="blue"'
 //code : 'doWhatYouWant()'
 });*/
 // Execute some script when the page is fully (DOM) ready
 chrome.tabs.executeScript(null, {code:"doWhatYouWant();"});
 }
});
function doWhatYouWant(){
 alert('I am inside doWhatYouWant'); 
 document.body.style.backgroundColor="blue";
}
// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Called when the user clicks on the browser action.
chrome.browserAction.onClicked.addListener(function(tab) {
 // No tabs or host permissions needed!
 alert('i am here');
 console.log('Turning ' + tab.url + ' red!');
 chrome.tabs.executeScript({
 code: 'document.body.style.backgroundColor="red"'
 });
});

Answer 1

Your doWhatYouWant function lives in your background page, so you won't be able to call it from a content script.

If the code you want to run is more than a couple lines long, consider putting it into a file in your extension and using the file: field in the InjectDetails parameter when you invoke chrome.tabs.executeScript.

Also, if you want it to run on every page, you can declare it as a content script in your manifest, instead of having the chrome.tabs.onUpdated listener.

Answer 2

There is the "prince" example on google content script tutorial: https://developer.chrome.com/extensions/content_scripts.html#pi I tried when learning to "google-extenioning"(?) and it works fine. Good Luck!

eidt - uh, forgot, files are here