AndIf snippet for MODX. Extended version of the 'If' snippet.

AndIf.php

<?php
/**
 * AndIf - for MODx Revolution
 *
 * Copyright 2011 by Luke Bagshaw (MODx forum user 'lucas')
 * This is a modified (extended) version of the 'If' snippet, created by 
 * Jason Coward <jason@modx.com> and Shaun McCormick <shaun@modx.com>
 *
 * AndIf is free software; you can redistribute it and/or modify it under the terms
 * of the GNU General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * AndIf is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * AndIf; if not, see <http://www.gnu.org/licenses/>
 *
 *
 *  USAGE:
 *
 * 	  [[!AndIf? 
 *   	 &condition=``   <-- `subject relation operand` (space delimited)
 *   	 &operator=``    <-- AND or OR (defaults to AND)
 *       &then=``        <-- result if conditions met  (defaults to 'true')
 *       &else=``        <-- result if not  (defaults to 'false')
 *    ]]
 *
 *    Multiple conditions delimited by a pipe '|'
 *       eg.  &condition=`x < 6|y = 5`
 *
 */
 
if (!empty($debug)) {
    print_r($scriptProperties);
    if (!empty($die)) die();
}
$modx->parser->processElementTags('',$condition,true,true);

$output = '';


// Set default params

$condition = !isset($condition) ? '' : $condition;
$operator = !isset($operator) ? 'and' : $operator;
$then = !isset($then) ? true : $then; 


// Set up function to compare subject to operand

if(!function_exists('compareSubject')) {
	function compareSubject($subject, $relation, $operand) {
		$relation = !empty($relation) ? $relation : '';
		$operand = !isset($operand) ? '' : $operand;
		if (isset($subject)) {
		    if (!empty($relation)) {
		        $relation = strtolower($relation);
		        switch ($relation) {
					case '!=':
					case 'neq':
					case 'not':
					case 'isnot':
					case 'isnt':
					case 'unequal':
					case 'notequal':
					    return ($subject != $operand);
					    break;
					case '<':
					case 'lt':
					case 'less':
					case 'lessthan':
					    return ($subject < $operand);
					    break;
					case '>':
					case 'gt':
					case 'greater':
					case 'greaterthan':
					    return ($subject > $operand);
					    break;
					case '<=':
					case 'lte':
					case 'lessthanequals':
					case 'lessthanorequalto':
					    return ($subject <= $operand);
					    break;
					case '>=':
					case 'gte':
					case 'greaterthanequals':
					case 'greaterthanequalto':
					    return ($subject >= $operand);
					    break;
					case 'isempty':
		            case 'empty':
					    return empty($subject);
					    break;
					case '!empty':
					case 'notempty':
					case 'isnotempty':
					    return !empty($subject) && $subject != '';
					    break;
					case 'isnull':
		            case 'null':			
					    return $subject == null || strtolower($subject) == 'null';
					    break;
					case 'inarray':
					case 'in_array':
					case 'in':
					case 'ia':
					    $operand = explode(',',$operand);
					    return in_array($subject,$operand);
					    break;	        
					case '==':
					case '=':
					case 'eq':
					case 'is':
					case 'equal':
					case 'equals':
					case 'equalto':
		            default:
		                return ($subject == $operand);
		                break;
		        }
		    }
		}
	}
}

// if no condition supplied, give error 'No condition supplied!'
if (!empty($condition)) {

	// add results of compareSubject to $proposition array to apply AND/OR logic		
	$proposition = array();
	
	// split conditions by pipe "|"
	$conditions = explode('|', $condition);
	
	foreach ($conditions as $condition) {
		// statements delimited by space ' ' to avoid conflict with in_array (uses commas)
		$statement = explode(' ', $condition);
		$subject = $statement[0];
		$relation = $statement[1];
		$operand = $statement[2];
			
		$proposition[] = compareSubject($subject,$relation,$operand);
		
	}
		
	// Apply AND/OR logic
	$operator = !empty($operator) ? $operator : 'and';
	$operator = !isset($operator) ? 'and' : $operator;
	if (isset($operator)) {
	    if (!empty($operator)) {
	        $operator = strtolower($operator);
			if ($operator == 'or') {
				$output = in_array(true, $proposition) ? $then : (isset($else) ? $else : false);
			}
			else {
				$output = !in_array(false, $proposition) ? $then : (isset($else) ? $else : false);
			}
	    }
	}

}

else { $output = 'ERROR: at least one condition required'; }


// return output
if (!empty($debug)) { var_dump($output); }
unset($subject,$statement,$relation,$operand,$condition);

return $output;
//?>

I tried to use snippet with pdoresources. When I try: &condition=[[+content]] notempty it doesnt works but &condition=[[+content]] empty works ok. I testet it with snippet "If" - in both cases it works fine