library/smarty/plugins/function.math.php

   1 <?php
   2 /**
   3  * Smarty plugin
   4  * @package Smarty
   5  * @subpackage plugins
   6  */
   7
   8
   9 /**
  10  * Smarty {math} function plugin
  11  *
  12  * Type:     function<br>
  13  * Name:     math<br>
  14  * Purpose:  handle math computations in template<br>
  15  * @link http://smarty.php.net/manual/en/language.function.math.php {math}
  16  *          (Smarty online manual)
  17  * @author   Monte Ohrt <monte at ohrt dot com>
  18  * @param array
  19  * @param Smarty
  20  * @return string
  21  */
  22 function smarty_function_math($params, &$smarty)
  23 {
  24     // be sure equation parameter is present
  25     if (empty($params['equation'])) {
  26         $smarty->trigger_error("math: missing equation parameter");
  27         return;
  28     }
  29
  30     $equation = $params['equation'];
  31
  32     // make sure parenthesis are balanced
  33     if (substr_count($equation,"(") != substr_count($equation,")")) {
  34         $smarty->trigger_error("math: unbalanced parenthesis");
  35         return;
  36     }
  37
  38     // match all vars in equation, make sure all are passed
  39     preg_match_all("!(?:0x[a-fA-F0-9]+)|([a-zA-Z][a-zA-Z0-9_]+)!",$equation, $match);
  40     $allowed_funcs = array('int','abs','ceil','cos','exp','floor','log','log10',
  41                            'max','min','pi','pow','rand','round','sin','sqrt','srand','tan');
  42
  43     foreach($match[1] as $curr_var) {
  44         if ($curr_var && !in_array($curr_var, array_keys($params)) && !in_array($curr_var, $allowed_funcs)) {
  45             $smarty->trigger_error("math: function call $curr_var not allowed");
  46             return;
  47         }
  48     }
  49
  50     foreach($params as $key => $val) {
  51         if ($key != "equation" && $key != "format" && $key != "assign") {
  52             // make sure value is not empty
  53             if (strlen($val)==0) {
  54                 $smarty->trigger_error("math: parameter $key is empty");
  55                 return;
  56             }
  57             if (!is_numeric($val)) {
  58                 $smarty->trigger_error("math: parameter $key: is not numeric");
  59                 return;
  60             }
  61             $equation = preg_replace("/\b$key\b/",$val, $equation);
  62         }
  63     }
  64
  65     eval("\$smarty_math_result = ".$equation.";");
  66
  67     if (empty($params['format'])) {
  68         if (empty($params['assign'])) {
  69             return $smarty_math_result;
  70         } else {
  71             $smarty->assign($params['assign'],$smarty_math_result);
  72         }
  73     } else {
  74         if (empty($params['assign'])){
  75             printf($params['format'],$smarty_math_result);
  76         } else {
  77             $smarty->assign($params['assign'],sprintf($params['format'],$smarty_math_result));
  78         }
  79     }
  80 }
  81
  82 /* vim: set expandtab: */
  83
  84 ?>