缩短文本而不会拆分单词或破坏html标签 [英] Shorten text without splitting words or breaking html tags

问题描述

我正在尝试在236个字符后截断文本，而不是将单词切成两半并保留html标签.这就是我现在正在使用的:

I am trying to cut off text after 236 chars without cutting words in half and preserving html tags. This is what I am using right now:

$shortdesc = $_helper->productAttribute($_product, $_product->getShortDescription(), 'short_description');
$lenght = 236;
echo substr($shortdesc, 0, strrpos(substr($shortdesc, 0, $lenght), " "));

尽管在大多数情况下都可以使用，但它不会使用html标签.例如，这段文字:

While this is working in most cases, it won't respect html tags. So for example this text:

Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. <strong>Stet clita kasd gubergren</strong>

将在标签仍处于打开状态的情况下被截断.有什么办法可以在236个字符后切断文本，但要尊重html标签?

will get cut off with the tag still being open. Is there any way to cut off text after 236 chars but respecting html tags?

推荐答案

为此遇到的最佳解决方案是来自CakePHP框架的TextHelper类

Best solution I have come across for this is from the CakePHP framework TextHelper class

这是方法

/**
* Truncates text.
*
* Cuts a string to the length of $length and replaces the last characters
* with the ending if the text is longer than length.
*
* ### Options:
*
* - `ending` Will be used as Ending and appended to the trimmed string
* - `exact` If false, $text will not be cut mid-word
* - `html` If true, HTML tags would be handled correctly
*
* @param string  $text String to truncate.
* @param integer $length Length of returned string, including ellipsis.
* @param array $options An array of html attributes and options.
* @return string Trimmed string.
* @access public
* @link http://book.cakephp.org/view/1469/Text#truncate-1625
*/
function truncate($text, $length = 100, $options = array()) {
    $default = array(
        'ending' => '...', 'exact' => true, 'html' => false
    );
    $options = array_merge($default, $options);
    extract($options);

    if ($html) {
        if (mb_strlen(preg_replace('/<.*?>/', '', $text)) <= $length) {
            return $text;
        }
        $totalLength = mb_strlen(strip_tags($ending));
        $openTags = array();
        $truncate = '';

        preg_match_all('/(<\/?([\w+]+)[^>]*>)?([^<>]*)/', $text, $tags, PREG_SET_ORDER);
        foreach ($tags as $tag) {
            if (!preg_match('/img|br|input|hr|area|base|basefont|col|frame|isindex|link|meta|param/s', $tag[2])) {
                if (preg_match('/<[\w]+[^>]*>/s', $tag[0])) {
                    array_unshift($openTags, $tag[2]);
                } else if (preg_match('/<\/([\w]+)[^>]*>/s', $tag[0], $closeTag)) {
                    $pos = array_search($closeTag[1], $openTags);
                    if ($pos !== false) {
                        array_splice($openTags, $pos, 1);
                    }
                }
            }
            $truncate .= $tag[1];

            $contentLength = mb_strlen(preg_replace('/&[0-9a-z]{2,8};|&#[0-9]{1,7};|&#x[0-9a-f]{1,6};/i', ' ', $tag[3]));
            if ($contentLength + $totalLength > $length) {
                $left = $length - $totalLength;
                $entitiesLength = 0;
                if (preg_match_all('/&[0-9a-z]{2,8};|&#[0-9]{1,7};|&#x[0-9a-f]{1,6};/i', $tag[3], $entities, PREG_OFFSET_CAPTURE)) {
                    foreach ($entities[0] as $entity) {
                        if ($entity[1] + 1 - $entitiesLength <= $left) {
                            $left--;
                            $entitiesLength += mb_strlen($entity[0]);
                        } else {
                            break;
                        }
                    }
                }

                $truncate .= mb_substr($tag[3], 0 , $left + $entitiesLength);
                break;
            } else {
                $truncate .= $tag[3];
                $totalLength += $contentLength;
            }
            if ($totalLength >= $length) {
                break;
            }
        }
    } else {
        if (mb_strlen($text) <= $length) {
            return $text;
        } else {
            $truncate = mb_substr($text, 0, $length - mb_strlen($ending));
        }
    }
    if (!$exact) {
        $spacepos = mb_strrpos($truncate, ' ');
        if (isset($spacepos)) {
            if ($html) {
                $bits = mb_substr($truncate, $spacepos);
                preg_match_all('/<\/([a-z]+)>/', $bits, $droppedTags, PREG_SET_ORDER);
                if (!empty($droppedTags)) {
                    foreach ($droppedTags as $closingTag) {
                        if (!in_array($closingTag[1], $openTags)) {
                            array_unshift($openTags, $closingTag[1]);
                        }
                    }
                }
            }
            $truncate = mb_substr($truncate, 0, $spacepos);
        }
    }
    $truncate .= $ending;

    if ($html) {
        foreach ($openTags as $tag) {
            $truncate .= '</'.$tag.'>';
        }
    }

    return $truncate;
}

其他框架可能对此问题具有类似(或不同)的解决方案，因此您也可以查看它们.我对Cake的熟悉是促使我链接到他们的解决方案的原因

Other frameworks may have similar (or different) solutions to this problem, so you could take a look at them too. My familiarity with Cake is what prompted my linking to their solution

只需在我正在处理OP文本的应用中测试此方法

Just tested this method in an app I'm working on with the OP's text

<?php 
echo truncate(
'Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. <strong>Stet clita kasd gubergren</strong>', 
236, 
array('html' => true, 'ending' => '')); 
?>

输出:

Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. <strong>Stet clita kasd gubegre</strong>

请注意，输出仅在完成最后一个单词之后停止，但包括完整的强标签

Notice the output stops just short of completing the last word, but includes the complete strong tags

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