Code Igniter Redirect Issues with GET parameters

Question

I am having difficulty with code igniter routing.

http://www.mysite.com goes to the right controller and does the right thing. However, http://www.mysite.com/?ref=p&t2=455 causes a 404 error. Also http://www.mysite.com/mycontroller/mymethod/?ref=p&t2=455 works fine.

I changed the uri_protocol in the config.php file and tried different values. Auto seems to work the best.

My theory is that code igniter is using the query parameters to do the routing. The problem is that these query parameter have nothing to do with routing.

How do I tell code igniter to ignore query parameters for the default controller?

Note, I followed the instructions online to remove the index.php from the URL. I dont think its causing a problem, but here is my .htaccess file just in case:

RewriteEngine On
RewriteBase /~trifecta/prod/

#Removes access to the system folder by users.
#Additionally this will allow you to create a System.php controller,
#previously this would not have been possible.
#'system' can be replaced if you have renamed your system folder.
RewriteCond %{REQUEST_URI} ^system.*
RewriteRule ^(.*)$ /index.php?/$1 [L]
#Checks to see if the user is attempting to access a valid file,
#such as an image or css document, if this isn't true it sends the
#request to index.php
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
#This last condition enables access to the images and css folders, and the robots.txt file
#Submitted by Michael Radlmaier (mradlmaier)
RewriteCond $1 !^(index\.php|images|robots\.txt|css)
RewriteRule ^(.*)$ index.php?/$1 [L]

Answer 1

With that rewrite rule RewriteRule ^(.*)$ /index.php?/$1, here are some examples of rewrites that are occuring:

http://www.mysite.com =>
http://www.mysite.com/index.php?/ (actually, this might not be being rewritten at all)

http://www.mysite.com/mycontroller/mymethod/?ref=p&t2=455 =>
http://www.mysite.com/index.php?/mycontroller/mymethod/?ref=p&t2=455

http://www.mysite.com/?ref=p&ts=455 =>
http://www.mysite.com/index.php?/?ref=p&t2=455

The first one will work whether it is being rewritten or not. CodeIgniter is processing either an empty query string (which is easy) or a query string of simply "/".

The second one (which also works) is being rewritten, but CodeIgniter is able to process its query string, which is /mycontroller/mymethod/?ref=p&t2=455. CI turns that into an array of segments as

[0] => mycontroller
[1] => mymethod
[2] => ?ref=p&t2=455

Array index 2 ultimately gets ignored by anything you're doing.

The third one (which does not work is being rewritten, and CodeIgniter can't process its query string at all. Its query string is rewritten to: /?ref=p&t2=455. That makes for an array of segments that looks like this:

[0] => ?ref=p&t2=455

which doesn't match any controller on your site.

Probably, you'll fix the whole thing by modifying the RewriteRule from
RewriteRule ^(.*)$ /index.php?/$1 to
RewriteRule ^(.*)$ /index.php/$1
at which point you'd probably want to change the uri_protocol config back to PATH_INFO.