Location of wp-config.php in WordPress 2.6

If you have CSS or JS external file that needs loading of options from the WP database, you need to load config file.

No, you don’t. There is absolutely NO case where you *must* load the config file yourself. The only reason to ever do that is simply lazy programming.

Instead, you need to make your plugin or theme intercept a special query variable to the main blog URL, instead of calling some separate file directly. Then you call the main URL via your AJAX with that special query variable.

Basically, you add your own query variable, then act on it when it is received, bypassing WordPress’ own output.

So, to add a query variable:

add_filter('query_vars', 'add_my_var');
function add_my_var($public_query_vars) {
	$public_query_vars[] = 'some_unique_identifier';
	return $public_query_vars;
}

Now, you need to check for that identifier and act on it:

add_action('template_redirect', 'my_var_output');
function my_var_output() {
	$myvalue=get_query_var('some_unique_identifier');
	if ($myvalue) {
		// do whatever output you like here
		// you can even use $myvalue to see what the request is for
		exit; // this stops WordPress entirely
	}
}

And there you go. Now you can make your javascript/AJAX call the main WordPress site URL with ?some_unique_identifier=myvalue and this will redirect to your plugin/theme and let you make any sort of output you like.

If you override the header with an application/json content type and throw some JSON back at it, and it’s perfect for an AJAX request. Also, because you’re in the plugin context, you have full access to all of WordPress’ functions.

Look at the plugin named WP-Microsummary. It does this perfectly and is a very good way to design your plugin. It’s also forward compatible and does not care where the wp-config is.

WP-Microsummary does just this, by adding a link tag pointing back at the current page, but which has “?microsummary=1” added onto the end of the URL.

Let me give you an example…

Let’s say you used this code in a plugin or a theme’s functions.php file:

add_filter('query_vars', 'add_my_var');
function add_my_var($public_query_vars) {
	$public_query_vars[] = 'myoption';
	return $public_query_vars;
}
add_action('template_redirect', 'my_var_output');
function my_var_output() {
	$myvalue=get_query_var('myoption');
	if ($myvalue) {
		switch ($myvalue) {
		case '1': echo 'I got a one!';
			break;
		case '2': echo 'I got a two!';
			break;
		}
		exit; // this stops WordPress entirely
	}
}

What happens when you go to your blog url + “?myoption=1” ? How about if you set myoption=2 in the URL?

Do you begin to see how this option can work?

But, if you’re doing a simple option of which stylesheet to load, then you don’t need to do this sort of thing anyway. Nor do you ever need to load wp-config manually. What exactly are you trying to do? Why do you think that you need to load wp-config? Because I guarantee you that you really don’t, you’re just taking the wrong approach.

Wow. That is one screwed up backwards way of doing things.

Here’s where he includes the stylesheet link tag:

function mytheme_wp_head() { ?>
<link href="<?php bloginfo('template_directory'); ?>/style.php" rel="stylesheet" type="text/css" />
...

The problem is that the the style.php basically just pulls out the value from the database and does an import of that sheet. Wrong way to do it, really. Instead, the original link tag should have pointed directly at that sheet. Something like this:

function mytheme_wp_head() {
global $options;
foreach ($options as $value) {
    if (get_settings( $value['id'] ) === FALSE) { $$value['id'] = $value['std']; } else { $$value['id'] = get_settings( $value['id'] ); } }
?>
<link href="<?php bloginfo('template_directory'); ?>/<?php echo $tn_body_style; ?>.css" rel="stylesheet" type="text/css" />
...

The remaining stuff in the style.php (the extra CSS) could be added to the main style.css file, naturally included in the header.

This has the added benefit of not *doubling your CPU load*, which is what that code does on every single page load, since it has to load WordPress twice.