Chrome extension getUrl not working in injected file

Question

I'm developing a Chrome extension, is there any way to get the chrome.extension.getURL('file path') method from injected file? I'm unable to access above method from injected file.

manifest.json

{
"name": "Name",
"version": "0.1",
"description": "Name chrome extension",
"background": {
"persistent": false,
"scripts": ["js/background.js"]
},
"permissions": [
"tabs", 
"https://*/*"
],
"content_scripts": [
{
  "matches": ["https://mail.google.com/*"],
  "js": ["js/content.js"],
  "run_at": "document_end"
}
],
"web_accessible_resources": [
"js/injected.js",
"html/popup.html"
],
"manifest_version": 2
}

injected.js

console.log("Ok injected file worked");
console.log("Url: ", chrome.extension.getURL('html/popup.html'));

contentScript.js

var s = document.createElement('script');
s.src = chrome.extension.getURL('js/injected.js');
(document.head || document.documentElement).appendChild(s);

Answer 1

No you cant, once you inject the script in a page, it cannot access chrome.extension.getURl. But you can communicate between your injected script and content script. One of the methods is using custom events.

mainfest.json:

{
"name": "Name",
"version": "0.1",
"description": "Name chrome extension",
"background": {
"persistent": false,
"scripts": ["js/background.js"]
},
"permissions": [
"tabs", 
"https://*/*"
],
"content_scripts": [
{
  "matches": ["https://mail.google.com/*"],
  "js": ["js/content.js"],
  "run_at": "document_end"
}
],
"web_accessible_resources": [
"js/injected.js",
"html/popup.html"
],
"manifest_version": 2
}

In your injected script :

console.log("Ok injected file worked");


document.addEventListener('yourCustomEvent', function (e)
{
    var url=e.detail;
    console.log("received "+url);
});

In your content script:

var s = document.createElement('script');
s.src = chrome.extension.getURL('js/injected.js');
(document.head || document.documentElement).appendChild(s);

s.onload = function(){

  var url=chrome.runtime.getURL("html/popup.html");

  var evt=document.createEvent("CustomEvent");
  evt.initCustomEvent("yourCustomEvent", true, true, url);
  document.dispatchEvent(evt);
};

Answer 2

You have to mention the file_path or file_names in the web_accessible_resources of extension manifest.
EG:

"web_accessible_resources":[
    "styles/*",
    "yourfilename.js"
  ]

After that you can have have the file in injected script by calling the method. "chrome.extension.getURL('yourfilename.js')";

Answer 3

chrome.extension.getURL is now depcrecated. Docs

Use chrome.runtime.getURL in the background script.

You need to send a message from your contentScript to backgroundScript

eg.

// contentScript.js

chrome.runtime.sendMessage({ message: "popup" }, function (response) {
  //
});

// backgroundScript.js

chrome.runtime.onMessage.addListener((request, sender, sendResponse) => {
  if (request.message === "popup") {
    chrome.tabs.create({ url: chrome.runtime.getURL("popup.html") });
  }
});