+<?php
+/**
+ * Smarty plugin
+ *
+ * This plugin is only for Smarty2 BC
+ * @package Smarty
+ * @subpackage PluginsFunction
+ */
+
+/**
+ * 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)
+ * @author Monte Ohrt <monte at ohrt dot com>
+ * @param array $params parameters
+ * @param object $template template object
+ * @return string|null
+ */
+function smarty_function_math($params, $template)
+{
+ // be sure equation parameter is present
+ if (empty($params['equation'])) {
+ trigger_error("math: missing equation parameter",E_USER_WARNING);
+ return;
+ }
+
+ $equation = $params['equation'];
+
+ // make sure parenthesis are balanced
+ if (substr_count($equation,"(") != substr_count($equation,")")) {
+ trigger_error("math: unbalanced parenthesis",E_USER_WARNING);
+ return;
+ }
+
+ // match all vars in equation, make sure all are passed
+ preg_match_all("!(?:0x[a-fA-F0-9]+)|([a-zA-Z][a-zA-Z0-9_]*)!",$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)) {
+ trigger_error("math: function call $curr_var not allowed",E_USER_WARNING);
+ return;
+ }
+ }
+
+ foreach($params as $key => $val) {
+ if ($key != "equation" && $key != "format" && $key != "assign") {
+ // make sure value is not empty
+ if (strlen($val)==0) {
+ trigger_error("math: parameter $key is empty",E_USER_WARNING);
+ return;
+ }
+ if (!is_numeric($val)) {
+ trigger_error("math: parameter $key: is not numeric",E_USER_WARNING);
+ return;
+ }
+ $equation = preg_replace("/\b$key\b/", " \$params['$key'] ", $equation);
+ }
+ }
+ $smarty_math_result = null;
+ eval("\$smarty_math_result = ".$equation.";");
+
+ if (empty($params['format'])) {
+ if (empty($params['assign'])) {
+ return $smarty_math_result;
+ } else {
+ $template->assign($params['assign'],$smarty_math_result);
+ }
+ } else {
+ if (empty($params['assign'])){
+ printf($params['format'],$smarty_math_result);
+ } else {
+ $template->assign($params['assign'],sprintf($params['format'],$smarty_math_result));
+ }
+ }
+}
+
+?>
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