box-o-sand/php-practice/web/html/wikipedia-tutorial/libs/plugins/function.math.php

83 lines
2.7 KiB
PHP

<?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));
}
}
}
?>