target=”_blank” did not work out of the box for me

so I changed the two functions to look like so:

function parse_external_links($matches){
	global $txfx_iel_use_target_blank;
	$addtext = ($txfx_iel_use_target_blank)? ' class="extlink" target="_blank"' :  ' class="extlink"';
	if ( wp_get_domain_name_from_uri($matches[3]) != wp_get_domain_name_from_uri($_SERVER["HTTP_HOST"]) ){
		return '<a href="' . $matches[2] . '//' . $matches[3] . '"' . $matches[1] . $matches[4] . $addtext . '>' . $matches[5] . '</a>';
	} else {
		return '<a href="' . $matches[2] . '//' . $matches[3] . '"' . $matches[1] . $matches[4] . '>' . $matches[5] . '</a>';
	}
}

and

function wp_external_links($text) {
	global $txfx_iel_use_target_blank;
	$pattern = '/<a (.*?)href="(.*?)\/\/(.*?)"(.*?)>(.*?)<\/a>/i';
	$text = preg_replace_callback($pattern,'parse_external_links',$text);

	$pattern2 = '/<a (.*?) class="extlink"(.*?)>(.*?)<img (.*?)<\/a>/i';
	$text = preg_replace($pattern2, '<a $1 $2>$3<img $4</a>', $text);
	return $text;
}

also, it might be a good idea to add a variable so that stripping the extlink class from image tags is optional. you’d just need a boolean variable like is implemented for the _blank option and then replace

$pattern2 = '/<a (.*?) class="extlink"(.*?)>(.*?)<img (.*?)<\/a>/i';
$text = preg_replace($pattern2, '<a $1 $2>$3<img $4</a>', $text);

with

if($stripclass){
	$pattern2 = '/<a>(.*?)<img (.*?)<\/a>/i';
	$text = preg_replace($pattern2, '</a><a>$3<img $4</a>', $text);
}