Enables !IE in wordpress's conditional comments for styles mechanism

better-wp-conditional-comments.php

<?php

add_filter( 'style_loader_tag', 'style_loader_tag_ccs', 10, 2 );

/**
 * Add support for non IE conditional comments
 *
 * Trac ticket: http://core.trac.wordpress.org/ticket/16118
 *
 * Usage:
 * After registering or enqueuing a script you need to append the CC to the style
 * handle via the $wp_styles class:
 *
 * $wp_styles->add_data( 'my-handle', 'adv_conditional', '!IE' );
 *
 * @param string $tag    The <link> tag to the CSS file
 * @param string $handle The handle the style was registerd with
 *
 * @return string    Returns the link tag for output
 */
function style_loader_tag_ccs( $tag, $handle ) {
	global $wp_styles;
	$obj = $wp_styles->registered[ $handle ];
	if ( isset( $obj->extra[ 'adv_conditional' ] ) && $obj->extra[ 'adv_conditional' ] ) {
		$cc = "<!--[if {$obj->extra['adv_conditional']}]>";
		$end_cc = '';
		if ( strstr( $obj->extra['adv_conditional'], '!IE' ) ) {
			$cc .= '<!-->';
			$end_cc = '<!--';
		}
		$end_cc .= "<![endif]-->\n";

		$tag = $cc . "\n" . $tag . $end_cc;
	}
	return $tag;
}

?>