Chrome extension inject js

Question

I want to create a new chrome extension but it don't work. I want to inject a js file into web page (all web page,not only one.If i push the chrome icon on google the script must execute,if i push the icon on facebook it must execute ect.)

this is background.js

chrome.browserAction.onClicked.addListener(function(tab) {

chrome.tabs.executeScript({

    null,{file: "backgrounds.js"} });
});

this is backgrounds.js

document.body.innerHTML="display div elem with style and id";

this is manifest.json

{
"name": "MyExt",
"description": "an extension,what else?",
"version": "1.0",
"permissions": [
    "activeTab"


],
"content_scripts": [
  {
      "matches": ["http://*/*"],
      "js": ["background.js"]
  }
],
"browser_action": {
    "default_title": "myExt"
},
"manifest_version": 2
}

what i wrong? I'm on windows 8.1 Update 1 with chrome last version

Answer 1

Your manifest is wrong: you should set background.js as your background script:

"background" : { "scripts" : [ "background.js" ] },

and remove the "content_scripts" section.

---

The "activeTab" permission means that you don't need to specify host permissions to inject in the current tab upon browser action click, so no other permissions are needed.

---

The tabId argument is optional, you can just drop it instead of passing null . And your invocation is wrong (you're wrapping two arguments in a single object). Here's the correct way:

chrome.browserAction.onClicked.addListener(function(tab) {
  chrome.tabs.executeScript({file: "backgrounds.js"});
});