Setting WordPress Multisite Locale

I’m running an English install of WordPress multisite with a few sites in languages other than English. I was dismayed see that multisite appeared to set the locale to en_US (English for the United States) for these non-English sites.

Source code before locale setter

Mike Little helped me to implement the following code to fix this:

<?php 

add_filter('locale','sitename_locale');
function sitename_locale($locale){  
global $current_blog; if (is_admin ()) // if this is the admin back end don't change the locale 
return $locale; if ('7' == $current_blog->blog_id){  // 7 is the site id for real men drink milk
return 'en_GB';
}else
if ('15' == $current_blog->blog_id){ // 15 is the site id for doug lawrence UAE
return 'ar_AE';
}else if
('5' == $current_blog->blog_id){ // 5 is the site id for douglawrence.cn
return 'zh_CN';
}
return $locale;
}

Source code after locale setter

The locales I used are:

en_GB   English for Great Britain

ar_AE    Arabic for the United Arab Emirates (to agree with the ccTLD of my Arabic domain)

zh_CN    Chinese for China (as opposed to other countries where Chinese is used)

The php file was uploaded to the /httpdocs/wp-content/mu-plugins directory using FTP.

External links to other locale information:

http://wordpress.stackexchange.com/questions/52419/setting-wplang-from-a-plugin

http://wordpress.org/plugins/admin-in-english/.