Using a regex to determine domain using JavaScript

Hi All,

If, as here at work, we have test, staging and production environments, such as:

http://test.my-happy-work.com

http://staging.my-happy-work.com

http://www.my-happy-work.com

I am writing some javascript that will redirect the browser to a url such as:

http://[environment].my-happy-work.com/my-happy-video

I need to be able to determine the current environment that we are in.

There is the possibility that I will currently be at a url such as:

http://[environment].my-happy-work.com/my-happy-path/my-happy-resource

I want to be able to grab the window.location but strip it of everything but:

http://[environment].my-happy-work.com

And then append to that string + "/" + "my-happy-video".

I am not skilled with regex, but I suppose there would be a way to parse the window.location up to the ".com"

Thoughts? Thanks!

From stackoverflow

• Why don't you just use window.location.hostname? That only contains the domain.

  You can combine that with window.location.protocol to generate what you need:

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

  More on window.location.

  Kekoa : Yes, then use some regex on the window.location.hostname to determine your subdomain(or environment as you call it), the regex would be something like window.location.hostname.match(/^(.*)\.my-happy-work\.com$/) which will return an array with the captured field(what is enclosed in parenthesis).

• Possibly another option would be to deploy separate code in each environment. Not totally separate code, but maybe set a variable to "PRODUCTION" when in production, or to "STAGING" when in staging mode.

  This decouples the mode your application should run in from the domain name.

  Peter Boughton : This is sensible. Don't even need to change the code though - just create an ini/config file on each machine that stores the mode (with a safe fallback if no file found).

  Peter Boughton : (This is assuming you have a server-side script to read such a file and, if necessary, generate the appropriate JS variable.)

• This expression should do the trick:

  ^https?://([a-z0-9]+)\.([a-z0-9\-]+)\.[a-z]+
  

• I wish to point you to: http://stackoverflow.com/questions/1910235/whats-a-good-regular-expression-to-capture-the-root-domain-of-a-given-url/1910347#1910347