new implementation of lib_input.php

tchalvak:~/ninjawars/deploy$ cat lib/common/lib_input.php
<?php
/*
 * Deals with getting and filtering user input (just from request).
 *
 * @package input
 */

// Input function that by default LEAVES INPUT COMPLETELY UNFILTERED
// To not filter some input, you have to explicitly pass in null for the third parameter,
// e.g. in('some_url_parameter', null, null)
function in($var_name, $default_val=null, $filter_callback=null){
    $result = isset($_REQUEST[$var_name])? $_REQUEST[$var_name] : $default_val;
    // Check that the filter function sent in exists.
    if($filter_callback && function_exists($filter_callback)){
        $result = $filter_callback($result);
    }
    return $result;
}

// Casts to an integer anything that can be cast that way non-destructively, otherwise null.
function sanitize_to_int($dirty){
	if($dirty == (int) $dirty){ // Cast anything that can be non-destructively cast.
		$res = (int) $dirty;
	} else {
		$res = null;
	}
	return $res;
}

// Strip everything except alphanumeric, underscore, and dash
function sanitize_to_word($dirty){
	return preg_replace("[^A-Za-z0-9_\-]", "", (string) $dirty);	
}

// Strip everything except words, digits, spaces, _, -, ., @, :, and slash for urls /
function sanitize_to_text($dirty){
    // Allows words, digits, spaces, _, -, ., @, :, and slash for urls /
	return preg_replace("/[^\w\d\s_\-\.\@\:\/]/", "", (string) $dirty);
}

function sanitize_to_email($dirty){
	return filter_var($dirty, FILTER_SANITIZE_EMAIL);
}

// Restrict an option to certain possibilities, e.g. for an orderby string, the possibilities would be an array of column names.
function restrict_to($original, $possibilities=array(), $default=null){
	foreach ($possibilities as $possibility){
		if ($original == $possibility){
			return $original;
		}
	}
	return $default;  // If the original doesn't match, just return the default.
}

?>