Global Variables in Chrome Extensions - google-chrome

Question

Is there a simple way where I can access a global javascript variable through content-scripts in chrome extensions?
Accessing global object from content script in chrome extension
I followed the steps mentioned in the above link, but it did not work out for me. Any help would be much appreciated.
Thanks,
Shankar

Answer 1

I managed to complete it. Thanks for the help. I used simple message passing to retrieve the value from the extension script to the content script. The place where I had missed was, the listener at the extension script needs to be at the background page (I think so). Once I changed that, it worked.

Answer 2

For those from the future looking for an answer to this question, here's how I do it:
function getVariable(v) {
var c = document.createElement("div");
c.id = 'var-data';
c.style.display = 'none';
document.body.appendChild(c);
var s = document.createElement('script');
s.innerHTML = 'document.getElementById("var-data").innerText=JSON.stringify('+v+');';
document.head.appendChild(s);
var data = JSON.parse(c.innerText);
c.remove();
s.remove();
return data;
}
And basic usage:
getVariable('globalVarIWantToAccess');
All this script goes in the content-script, not the code for the main webpage, which means that no co-operation is needed from the webpage itself. Basically, the getVariable function creates a script element which is injected into the main page. This script tag retrieves the requested global variable and puts the data into a new div. The function then gets this data from the new div, deletes the new div, deletes the new script element and returns the data.