function smarty_function_math in Quiz 6.5

Same name and namespace in other branches

1. 6.6 includes/moodle/lib/smarty/plugins/function.math.php \smarty_function_math()

Smarty {math} function plugin

Type: function<br> Name: math<br> Purpose: handle math computations in template<br> @link http://smarty.php.net/manual/en/language.function.math.php {math} (Smarty online manual)

Parameters

array:

Smarty:

Return value

string

File

includes/moodle/lib/smarty/plugins/function.math.php, line 21

Code

function smarty_function_math($params, &$smarty) {

  // be sure equation parameter is present
  if (empty($params['equation'])) {
    $smarty
      ->trigger_error("math: missing equation parameter");
    return;
  }
  $equation = $params['equation'];

  // make sure parenthesis are balanced
  if (substr_count($equation, "(") != substr_count($equation, ")")) {
    $smarty
      ->trigger_error("math: unbalanced parenthesis");
    return;
  }

  // match all vars in equation, make sure all are passed
  preg_match_all("!(?:0x[a-fA-F0-9]+)|([a-zA-Z][a-zA-Z0-9_]+)!", $equation, $match);
  $allowed_funcs = array(
    'int',
    'abs',
    'ceil',
    'cos',
    'exp',
    'floor',
    'log',
    'log10',
    'max',
    'min',
    'pi',
    'pow',
    'rand',
    'round',
    'sin',
    'sqrt',
    'srand',
    'tan',
  );
  foreach ($match[1] as $curr_var) {
    if ($curr_var && !in_array($curr_var, array_keys($params)) && !in_array($curr_var, $allowed_funcs)) {
      $smarty
        ->trigger_error("math: function call {$curr_var} not allowed");
      return;
    }
  }
  foreach ($params as $key => $val) {
    if ($key != "equation" && $key != "format" && $key != "assign") {

      // make sure value is not empty
      if (strlen($val) == 0) {
        $smarty
          ->trigger_error("math: parameter {$key} is empty");
        return;
      }
      if (!is_numeric($val)) {
        $smarty
          ->trigger_error("math: parameter {$key}: is not numeric");
        return;
      }
      $equation = preg_replace("/\\b{$key}\\b/", $val, $equation);
    }
  }
  eval("\$smarty_math_result = " . $equation . ";");
  if (empty($params['format'])) {
    if (empty($params['assign'])) {
      return $smarty_math_result;
    }
    else {
      $smarty
        ->assign($params['assign'], $smarty_math_result);
    }
  }
  else {
    if (empty($params['assign'])) {
      printf($params['format'], $smarty_math_result);
    }
    else {
      $smarty
        ->assign($params['assign'], sprintf($params['format'], $smarty_math_result));
    }
  }
}