library/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  * @param array
  18  * @param Smarty
  19  * @return string
  20  */
  21 function smarty_function_math($params, &$smarty)
  22 {
  23     // be sure equation parameter is present
  24     if (empty($params['equation'])) {
  25         $smarty->trigger_error("math: missing equation parameter");
  26         return;
  27     }
  28
  29     $equation = $params['equation'];
  30
  31     // make sure parenthesis are balanced
  32     if (substr_count($equation,"(") != substr_count($equation,")")) {
  33         $smarty->trigger_error("math: unbalanced parenthesis");
  34         return;
  35     }
  36
  37     // match all vars in equation, make sure all are passed
  38     preg_match_all("!\!(0x)([a-zA-Z][a-zA-Z0-9_]*)!",$equation, $match);
  39     $allowed_funcs = array('int','abs','ceil','cos','exp','floor','log','log10',
  40                            'max','min','pi','pow','rand','round','sin','sqrt','srand','tan');
  41     foreach($match[2] as $curr_var) {
  42         if (!in_array($curr_var,array_keys($params)) && !in_array($curr_var, $allowed_funcs)) {
  43             $smarty->trigger_error("math: parameter $curr_var not passed as argument");
  44             return;
  45         }
  46     }
  47
  48     foreach($params as $key => $val) {
  49         if ($key != "equation" && $key != "format" && $key != "assign") {
  50             // make sure value is not empty
  51             if (strlen($val)==0) {
  52                 $smarty->trigger_error("math: parameter $key is empty");
  53                 return;
  54             }
  55             if (!is_numeric($val)) {
  56                 $smarty->trigger_error("math: parameter $key: is not numeric");
  57                 return;
  58             }
  59             $equation = preg_replace("/\b$key\b/",$val, $equation);
  60         }
  61     }
  62
  63     eval("\$smarty_math_result = ".$equation.";");
  64
  65     if (empty($params['format'])) {
  66         if (empty($params['assign'])) {
  67             return $smarty_math_result;
  68         } else {
  69             $smarty->assign($params['assign'],$smarty_math_result);
  70         }
  71     } else {
  72         if (empty($params['assign'])){
  73             printf($params['format'],$smarty_math_result);
  74         } else {
  75             $smarty->assign($params['assign'],sprintf($params['format'],$smarty_math_result));
  76         }
  77     }
  78 }
  79
  80 /* vim: set expandtab: */
  81
  82 ?>