04.12.07
Multibyte String Truncate Modifier for Smarty - mb_truncate
When working with Smarty, a PHP templating engine, I discovered that while the regular truncate modifier works great on ASCII strings, it doesn’t work with multibyte strings, i.e. UTF-8 encoded strings. This leads to problems in internationalization (i18n), as UTF-8 is the popular encoding for non-Latin alphabets nowdays. The problem can be solved by modifying the built-in truncate modifier and create a new one that takes an additional argument, the charset of the string, and acts accordingly. The new modified modifier, mb_truncate is implemented below.
<?php /** * Smarty plugin * @package Smarty * @subpackage plugins */ /** * Smarty truncate modifier plugin * * Type: modifier<br> * Name: mb_truncate<br> * Purpose: Truncate a string to a certain length if necessary, * optionally splitting in the middle of a word, and * appending the $etc string or inserting $etc into the middle. * This version also supports multibyte strings. * @link http://smarty.php.net/manual/en/language.modifier.truncate.php * truncate (Smarty online manual) * @author Guy Rutenberg <guyrutenberg@gmail.com> based on the original * truncate by Monte Ohrt <monte at ohrt dot com> * @param string * @param integer * @param string * @param string * @param boolean * @param boolean * @return string */ function smarty_modifier_mb_truncate($string, $length = 80, $etc = '...', $charset='UTF-8', $break_words = false, $middle = false) { if ($length == 0) return ''; if (strlen($string) > $length) { $length -= min($length, strlen($etc)); if (!$break_words && !$middle) { $string = preg_replace('/\s+?(\S+)?$/', '', mb_substr($string, 0, $length+1, $charset)); } if(!$middle) { return mb_substr($string, 0, $length, $charset) . $etc; } else { return mb_substr($string, 0, $length/2, $charset) . $etc . mb_substr($string, -$length/2, $charset); } } else { return $string; } } /* vim: set expandtab: */ ?>
The license for the code is LGPL (same as Smarty’s). To install to modifier just put it under /smarty/plugins/modifier.mb_truncate.php.
Using the mb_truncate modifier is similar to truncate.
//$some_string is a string of utf-8 variables assign via php {$some_string|mb_truncate:|mb_truncate:13:"...":'UTF-8'}
The modifier also supports the break words, and truncate in the middle flags of the original truncate.







Miroslav Mollov said,
March 4, 2008 at 3:17 pm
Nice !
It is good idea !
curzon said,
April 9, 2008 at 9:57 am
i have a 7 line paragraph in my database. now i wanna show only 3 line from this paragraph using PHP. which function i can use ?
Guy said,
April 9, 2008 at 10:48 am
Hi curzon,
A simple solution would be to call strpos (multiple times) to find the third occurrence of “\n” and now return the substring till this point, it will only have 3 lines.
I don’t know any existing modifier for Smarty, so you will have to wrap it before you can use it in Smarty. See the mb_truncate modifier as an example how to do it.
Pierre said,
April 10, 2008 at 3:24 pm
That was exactly what I needed. Took me about two hours to figure out that the problem was not in the database but with Smartys truncate
Then I googled and came here -> problem solved.
Thanks,
Pierre