<?php

/**

 * Smarty plugin

 *

 * @package    Smarty

 * @subpackage PluginsFilter

 */

/**

 * Smarty trimwhitespace outputfilter plugin

 * Trim unnecessary whitespace from HTML markup.

 *

 * @author   Rodney Rehm

 *

 * @param string $source input string

 *

 * @return string filtered output

 * @todo     substr_replace() is not overloaded by mbstring.func_overload - so this function might fail!

 */

function smarty_outputfilter_trimwhitespace($source) {

    $store = array();

    $_store = 0;

    $_offset = 0;

    // Unify Line-Breaks to \n

    $source = preg_replace("/\015\012|\015|\012/", "\n", $source);

    // capture Internet Explorer Conditional Comments

    if (preg_match_all('#<!--\[[^\]]+\]>.*?<!\[[^\]]+\]-->#is', $source, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER)) {

        foreach ($matches as $match) {

            $store[] = $match[0][0];

            $_length = strlen($match[0][0]);

            $replace = '@!@SMARTY:' . $_store . ':SMARTY@!@';

            $source = substr_replace($source, $replace, $match[0][1] - $_offset, $_length);

            $_offset += $_length - strlen($replace);

            $_store++;

        }

    }

    // Strip all HTML-Comments

    // yes, even the ones in <script> - see http://stackoverflow.com/a/808850/515124

    $source = preg_replace('#<!--.*?-->#ms', '', $source);

    // capture html elements not to be messed with

    $_offset = 0;

    if (preg_match_all('#(<script[^>]*>.*?</script[^>]*>)|(<textarea[^>]*>.*?</textarea[^>]*>)|(<pre[^>]*>.*?</pre[^>]*>)#is', $source, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER)) {

        foreach ($matches as $match) {

            $store[] = $match[0][0];

            $_length = strlen($match[0][0]);

            $replace = '@!@SMARTY:' . $_store . ':SMARTY@!@';

            $source = substr_replace($source, $replace, $match[0][1] - $_offset, $_length);

            $_offset += $_length - strlen($replace);

            $_store++;

        }

    }

    $expressions = array(

        // replace multiple spaces between tags by a single space

        // can't remove them entirely, becaue that might break poorly implemented CSS display:inline-block elements

        '#(:SMARTY@!@|>)\s+(?=@!@SMARTY:|<)#s' => '\1 \2',

        // remove spaces between attributes (but not in attribute values!)

        '#(([a-z0-9]\s*=\s*("[^"]*?")|(\'[^\']*?\'))|<[a-z0-9_]+)\s+([a-z/>])#is' => '\1 \5',

        // note: for some very weird reason trim() seems to remove spaces inside attributes.

        // maybe a \0 byte or something is interfering?

        '#^\s+<#Ss' => '<',

        '#>\s+$#Ss' => '>',

    );

    $source = preg_replace(array_keys($expressions), array_values($expressions), $source);

    // note: for some very weird reason trim() seems to remove spaces inside attributes.

    // maybe a \0 byte or something is interfering?

    // $source = trim( $source );

    $_offset = 0;

    if (preg_match_all('#@!@SMARTY:([0-9]+):SMARTY@!@#is', $source, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER)) {

        foreach ($matches as $match) {

            $_length = strlen($match[0][0]);

            $replace = $store[$match[1][0]];

            $source = substr_replace($source, $replace, $match[0][1] + $_offset, $_length);

            $_offset += strlen($replace) - $_length;

            $_store++;

        }

    }

    return $source;

}