CodeIgniter - multiple entry paths with other CMS on same site - wordpress

Question

Here's a weird question for everyone. I've got a situation where an existing site has wordpress running on it as the main CMS to the site, there's some additional code which can't be implemented in WP because of URL structures etc so we'd like to put CI on the same host.
However, there's two potential entry points needed for CI on that site - lets call them /userside and /adminside
I want both to share the same application and system folders which are all in the same accessible folder space.
I've got /userside working co-existing with WP quite easily.
Here's the .htaccess file
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^/userside [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /userside/index.php [L]
RewriteRule ^/adminside [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /adminside/index.php [L]
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
My folder layout is as follows
FTP ROOT/
ci/ <- codeigniter root
application/
system/
http/
index.php <- WP index.php
adminside/
index.php <- CI index.php
userside/
index.php <- CI index.php
... wp-content etc
I've copied userside's files to adminside and tried symlinking as well but neither work.
In CI's application/config i've modified the base_url to be:
list($_trash, $_base, $rest) = explode('/', $_SERVER['REQUEST_URI'], 3);
$config['base_url'] = "http://".$_SERVER['HTTP_HOST']."/".$_base;
Which means it automatically puts the first segment of the URI as the application base, i've debugged this code and it sets it correctly.
Now here's the problem, when I access /userside/somecontroller, it works, however, when I access /adminside/somecontroller it doesn't. I get a 404 page.
I can get it to access the default controller's index() function by just accessing /adminside - that works but not when I specify a controller and method.
eg:
http://www.mysite.com/userside/mycontroller/mymethod <- works
http://www.mysite.com/userside/mycontroller/mymethod <- doesn't work - 404 displayed
/userside was set up first and I can't see anywhere that ties CI to /userside other than in application/config/config.php
Permissions have been checked and are identical, owners are identical.
Anyone got an idea why this isn't working? I don't want to have to split the site into a subdomain as we have specific reasons and as it works with /userside there's only something simple keeping me from making /adminside work as well.

Answer 1

You need the RewriteRule to get rid of index.php and append the method:
<IfModule mod_rewrite.c>
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^/userside(.*)$ /userside/index.php$1 [L]
RewriteRule ^/adminside(.*)$ /adminside/index.php$1 [L]
RewriteRule ^(.*)$ index.php/$1 [L]
</IfModule>

Answer 2

This was a little less complicated than I thought.
You simply put CI's .htaccess in the sub-folder you want to run CI in and then set the appropriate site URL variables to match.
I did find a document that showed how to give you access to all of WP's libraries from CI by simply loading wp-load.php from the root of the WP side in CI's index.php.
Hope this helps other people.