Multiple Domains and Web Sites in a single Joomla! installation

A 'Multi-Site' Solution: How to Integrate Multiple Domains into a Single Joomla! Installation.

Although it's a best-practice to give every web site it's own domain, Joomla! installation and database there may be special conditions in which a multi-site solution under a single Joomla! install is warranted.

Although this article is oriented toward developers working on a site with Linux+Apache it should work for most of the popular web hosting configurations.

Example of Conditions where this Multi-Site Solution Makes Sense:

A small business 'Johnson Candies' has two separate but related brands; Red Candy and Yellow Candy. They require a single Joomla!-based web site where both candy-types are visible, each with its own home page on the Joomla! site which corresponds to a given domain:

http://www.redjohnsoncandy.com (example only) http://www.yellowjohnsoncandy.com (example only)

Additionally, each Brand and Site requires it's own design, a yellow template for one, a red template, for the other.

Benefits of this Solution:

By including both brands into a single Joomla! web installation, Johnson Candies is able to save editing-time (only one login), to share articles or data across both brands (or mini-sites) and to use a single feature, such as a contact us form, for both brands.

Step One: Prepare Your Domains

Use a single domain for your hosting account, as normal. Park any additional domains on top of that account domain. (as in cPanel). For the purpose of this tutorial, we will park redjohnsoncandy.com on top of the base yellowjohnsoncandy.com domain name.

Step Two: Install and Setup Joomla! Normally

- Install & Setup Joomla! Normally - Develop Articles and Menus/Modules for Each Mini-Site

Step Three: Create Templates

Next develop and install (2+) templates to Joomla! - one for each 'mini-site' that you wish to have. In the above example, you would create a template for red candy named Red Template and a template for yellow candy named Yellow Template. Once the templates are installed to the site, assign them to the relevant menu items, using Joomla! template manager, in the Joomla! Administrator area.

Final Step, Option #1: Create an htaccess (Apache) redirect.

Note: Enable SEF URL's in Joomla! First One option is to use htaccess (Apache) to redirect inquiries to a given domain to a specific Joomla! page.

Our goal is to redirect any inquries to the Red Candy domain name to a given page on the Joomla! site. In this example, we redirect any inquiries to redjohnsoncandy.com to a category-blog page. You would have previously assigned the 'red candy' template to this menu item, to create the illusion of a separate site.

#The following rule works, but it changes which domain name displays.
RewriteCond %{HTTP_HOST} ^redjohnsoncandy.com$ [OR]
RewriteCond %{HTTP_HOST} ^www.redjohnsoncandy.com$
RewriteRule ^(.*)$ http://www.yellowjohnsoncandy.com/index.php?option=com_content&view=category&layout=blog&id=3&Itemid=12 [R=301,L]

Well, that works - but you can see the drawback immediately. Although the user is successfully viewing the Red Candy site, they will still see the Yellow Candy domain name. Unfortunately, if you are using both htaccess and domain-parking (technically a redirect) - this is necessary in order to avoid creating a LOOP.

Final Step, Option #2: Create a PHP Header Redirect

This solution has the benefit of keeping the illusion of separate domains/web sites apparent to the visitor. Instead of using htaccess (Apache) for our redirect, we use one of the templates on the site.

In this example, the base domain is redjohnsoncandy.com. You have created a template for that area named Red Template. The trick is to open 'Red Template's' index.php file and add the following to the head area.

<?php

$domain = $_SERVER["HTTP_HOST"];
if (($domain == "redjohnsoncandy.com") ||
   ($domain == "www.redjohnsoncandy.com")) { 

   header("location: http://www.redjohnsoncandy.com/index.php?option=com_content&view=category&layout=blog&id=3&Itemid=12"); 

} 

?>

Here's the benefit: The visitor will now be redirected to the appropriate Red Site page, that has the Red Template assigned to it *only* in the case where they have arrived at the 'red site' domain name. Otherwise, the conditional PHP rule is ignored, and the base Yellow Site loads.

Thus, two domains, two sites, one Joomla!

Please Note:

This tip is only useful in specific circumstances.

Otherwise it is a far more elegant and efficient solution to use multiple Joomla! installations, parked domains, etc, as your needs require.