Question

I have created one simple extension in Google chrome,
below is my manifast.json

{
    "name":"Hello World",
    "version":"1.0",
    "manifest_version":2,
    "description":"The first extension that I made.",
    "browser_action":{
        "default_icon":"icon.png"
    },
    "background": {
        "scripts": ["background.js"]
    },
    "permissions":[
        "tabs", "http://*/*", "https://*/*"
    ]
} 

and below is my background.js.

alert('test application');

Now, Extension is getting loaded, but not running background page.

Can some one please help me on this?
Its working fine with version 24, but I want to create an extension to test my web page, which should run on any Chrome versions.

Answer 1

Why still use Chrome 11? It’s too old. The stable channel of Chrome 24 was just released.

But if you do need to support older versions of Chrome that don’t support “manifest_version”: 2 (say, to support other Chromium based browsers that are not up-to-date with Chrome), here’s some suggestions.

• Write sereval versions of manifest.json and package you extensions with different versions of Chrome to support both older and latest versions of Chrome. Say your_extension_chrome17.crx and your_extension_chrome18.crx (manifest version 2). Ask your users to download the appropriate package according to their Chrome version. Note that you have to use "background_page": "bg.html" where bg.html is your background page that contains background scripts instead of "background": {...} (and “background_page” cannot be used in v2 manifest). "manifest_version": 2 will be silently ignored before Chrome 17, so this won’t be a trouble.
• Take a look at https://developer.chrome.com/trunk/extensions/whats_new.html to have a general idea when those new APIs are supported and consider workarounds for old versions.
• Unknown permissions (supported in newer versions) will be silently ignored unless you need to support Chrome 6 or older (are you sure?).
• In order to have auto update support, you need to take care of the update manifest. Use minprodversion to prevent packages for new versions from being installed (also set minimum_chrome_version in manifest.json) and include multiple entries in the update manifest. Note that an element can only contain one element so you have to use multiple elements. See https://developer.chrome.com/extensions/autoupdate.html for more information. For example:

<?xml version='1.0' encoding='UTF-8'?>
<gupdate xmlns='http://www.google.com/update2/response' protocol='2.0'>
  <app appid='aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'>
    <updatecheck codebase='http://myhost.com/mytestextension/your_extension_chrome18.crx' version='2.0' prodversionmin='18.0.1025.142'/>
  </app>
  <app appid='aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'>
    <updatecheck codebase='http://myhost.com/mytestextension/your_extension_chrome17.crx' version='2.0' prodversionmin='3.0.193.0'/>
  </app>
</gupdate>

And be sure to test your extension thoroughly in different versions, though it would be a great headache.
And as far as I know, you cannot use these tricks for extensions hosted in Chrome Web Store.