Injecting content script for Chrome extension isn't working

Question

I've researched this topic a ton but something isn't clicking. I'm trying to make a simple Chrome extension. The details aren't important, but basically when the user clicks on a certain button on a certain website, the page is redirected to a different URL. I've put in dummy URLs just for illustration. Here is my code:

manifest.json

{
    "manifest_version": 2,
    "name": "Blah",
    "version": "1.0",
    "description": "Blah blah",
    "icons": {  "16": "icon16.png",
            "48": "icon48.png",
            "128": "icon128.png" },
    "content_scripts": [
        {
        "matches": ["*://url1.com/*"],
        "js": ["contentscript.js"]
        }
    ],
    "web_accessible_resources": ["script.js"]
}

contentscript.js (found this on another Stack Overflow question, not totally sure how it works)

var s = document.createElement("script");
s.src = chrome.extension.getURL("script.js");
s.onload = function() {
    this.remove();
};
(document.head || document.documentElement).appendChild(s);

script.js

document.getElementById("id1").addEventListener("click", redirect);
function redirect() {
    console.log("Testing!");    // This works!
    window.location.replace("url2.org");
}

The text is logged to the console when I click the appropriate button, so I know I'm doing something right. However, I'm guessing I'm not actually injecting the script into the page, and that's why my page isn't redirecting. Any help would be appreciated!

Answer 1

Here is an example:

script.js

// wait that page finished loading
window.addEventListener("load", function load(event){
// for the current tab, inject the "inject.js" file & execute it
    chrome.tabs.executeScript(tab.ib, {
        file: 'inject.js'
    });
},false);

inject.js

// this is the code which will be injected into a given page...

document.getElementById("id1").addEventListener("click", redirect);
function redirect() {
   console.log("Testing!");    // This works!
   window.location.replace("url2.org");
}

Manifest.json

{
  "name": "Inject",
  "version": "0.0.1",
  "manifest_version": 2,
  "description": "Injecting stuff",
  "content_scripts": [{
      "matches": ["http://example.com/*"],
       "js": ["script.js"]
  }],
  "permissions": [
    "http://example.com/*",
    "tabs"
  ]
}