Google Chrome Plugin: How to get domain from URL (tab.url)

Question

Using the Google Chrome API's tab.url value, what is the best method to get just the domain from the entire value?

In JavaScript I would use window.location.protocol & window.location.hostname. For example something like this:

var domain = window.location.protocol + "//" + window.location.hostname; 

But that gets the extension domain and not the tab so cannot use that method. So with a function similar to the one below... How would I strip just the domain from the tab.url value?

function show_alert() {     chrome.tabs.getSelected(null, function(tab) {         var currentURL = tab.url;         alert(currentURL);     }); } 

Answer 1

Since this question was originally answered, a better solution has appeared.

Most modern browsers now support use of the URL constructor, which provides access to href, hostname, path and all standard ways of splitting up a URL.

To get the domain, you could do the following:

chrome.tabs.query({ active: true, currentWindow: true }, function (tabs) {   var tab = tabs[0];   var url = new URL(tab.url)   var domain = url.hostname   // `domain` now has a value like 'example.com' }) 

Answer 2

First of all, domains don't include a protocol. I have created a regular expression for your problem. To get the hostname (you'd want to do this as IP addresses are not domains) of a URI, use the the following:

var domain = uri.match(/^[\w-]+:\/{2,}\[?([\w\.:-]+)\]?(?::[0-9]*)?/)[1]; // Given uri = "http://www.google.com/", domain == "www.google.com" 

If you want the origin (protocol + host (not hostname, there's a difference) + optional port) instead of the domain, use the following:

var origin = uri.match(/^[\w-]+:\/{2,}\[?[\w\.:-]+\]?(?::[0-9]*)?/)[0]; // Given uri = "http://www.google.com/", origin == "http://www.google.com"