Understanding the query string after .htaccess rewrite

Question

I'm of the understanding that Wordpress' .htaccess, like below:

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress

sends all queries through to the index.php (unless the filename exists on the server etc).

So, if I go to http://example.com/checkout Wordpress rewrites that as http://example.com/index.php?pagename=checkout.

But what I don't understand is that I have, at the top of a page template

<?php print_r($_GET) ?>

and when I navigate to http://example.com/checkout that returns Array(). I'd expect something like Array('pagename' => 'checkout');

How can I access the variables that Wordpress uses when handling a URL?

Answer 1

It's not really rewriting the URL in the conventional sense, URL parsing happens entirely within PHP.

You can access the query vars in the global $wp_query->query_vars, or with the get_query_var function.

Also note that parse_request is the earliest action where this info will be available.

Answer 2

It calls index.php, not index.php?page=...

I'm not sure how WordPress does its routing, but you could use $_SERVER['PATH_INFO'] or $_SERVER['REQUEST_URI']

Answer 3

Don't get fooled by the names. mod_rewrite Rewrite Rules and WordPress Rewrite Rules are two very different things.

In the .htaccess, there are mod_rewrite rules that don't do anything other than run WP's index.php for any requests that don't directly hit an existing file or directory.

To figure out, what /checkout means, WordPress then relies on its' own set of rewrite rules which have nothing at all to do with mod_rewrite, so don't get confused.

WordPress' $redirect part looks like it passes variables via HTTP GET, but that isn't really the case. Those will be used as rewrite tags. See the documentation for add_rewrite_rule for a few examples and further explanation.