Smarty

[messju]

i did a rainy-afternoon-boring-compiling-compiler-math-plugin yesterday.

[php:1:08b523b002]<?php

/**
* Smarty {math} compiler function plugin
*
* Type: compiler function<br>
* Name: math<br>
* Purpose: compute
* @link http://smarty.php.net/manual/en/language.function.math.php
* (Smarty online manual)
* @version 0.2
* @author messju mohr <messju@lammfellpuschen.de>
* @param array Format: array('equation' => string, ...)
* @param Smarty_Compiler
*/

function smarty_compiler_math($tag_args, &$compiler)
{

$_attrs = $compiler->_parse_attrs($tag_args);

/* check equation-attribute */
if (!isset($_attrs['equation'])) {
$compiler->_syntax_error('{math} missing equation-attribute');
return;
}

if (!preg_match('/\s*equation\s*=\s*('.$compiler->_qstr_regexp.')/s', $tag_args, $_match)) {
$compiler->_syntax_error('{math} equation-attribute has to be a constant string');
return;
}

$_equation = $compiler->_dequote($_match[1]);

/* save format-attribute */
if (isset($_attrs['format'])) {
$_format = $_attrs['format'];
unset($_attrs['format']);
} else {
$_format = null;
}

/* save assign-attribute */
if (isset($_attrs['assign'])) {
$_assign = $_attrs['assign'];
unset($_attrs['assign']);
} else {
$_assign = null;
}
unset($_attrs['equation']);

$_result = '';
/* handle optinal vars */
if (count($_attrs)>0) {
$_result .= '$__math_vars = array(';
$_equation = preg_replace('/\b('.implode('|', array_keys($_attrs)).')\b/', '$__math_vars.$1', $_equation);
$_sep = '';
foreach ($_attrs as $_key=>$_value) {
$_result .= "$_sep'$_key'=>$_value";
$_sep = ', ';
}
$_result .= ');';
}

/* compile equation */
$_code = $compiler->_compile_if_tag($_equation);
$_code = substr($_code, 10, -5);
$_code = str_replace('$this->_tpl_vars[\'__math_vars\']', '$__math_vars', $_code);


/* handle format-attribute */
if (isset($_format)) {
$_code = "sprintf($_format, $_code)";
}

/* handle assign-attribute */
if (isset($_assign))
$_result .= "\$this->assign($_assign, $_code);";
else {
$_result .= "echo $_code;";
}

if (count($_attrs)>0) {
$_result .= 'unset($__math_vars);';
}

return $_result;

}

/* vim: set expandtab: */

?>[/php:1:08b523b002]

the fun-part is parsing the equation: it uses the if-expression-parser. it should work with 2.5.0 and 2.6.0 at least. the idea is to use the same parsers for both {if} and {math} to ensure they follow the same syntax. i didn't test compatibility to the {math}-version of the distribution thoroughly. if somebody wants to test it's compatibility i'm interested in the results.

greetings
messju

[EDIT: fixed intermixed format and assign (copy+paste bug)]