Simple Snippet / Filter to automatically differentiate between internal and external links

<?php
if (is_numeric ($input)){
	$url = $modx->makeUrl($input);
	$fullLink = 'href="'.$url.'"';
}else{
	$fullLink = 'href="'.$input.'" target="_blank"';
}
return $fullLink;

[[+tv.link:notempty=`<a [[+tv.link:intExtLink]] title="View more information">`]]
    <img src="[[+tv.image]]">
[[+tv.link:notempty=`</a>`]]

<?php
if (is_numeric ($input)){
	$input = (int)$input;
	$result = $modx->makeUrl($input);
}else{
	$external = true;
	$result = $input;
}

if (($options != '') && ($external == true)){
	$result = 'target="'.$options.'"';
} 
elseif (($options != '') && ($external != true)){
	return ' ';
}

return $result;

[[+tv.link:notempty=`<a href="[[+tv.link:intExtLink]]" [[+tv.link:intExtLink=`_blank`]] title="View more information">`]]
    <img src="[[+tv.image]]">
[[+tv.link:notempty=`</a>`]]

	$(window).load( function() {
		$.extend($.expr[':'], {
			external: function(obj) {
				return obj.href !== undefined && obj.href !== '' && !obj.href.match(/^mailto\:/) && (obj.hostname != location.hostname);
			}
		});
		// Add target="_blank" to all external links, has to happen at the end of the parsing process!
		$('a:external, a.newtab').attr('target','_blank');
	});