使用 PHP substr() 和 strip_tags() 同时保留格式且不破坏 HTML

Using PHP substr() and strip_tags() while retaining formatting and without breaking HTML

提问by Peter Craig

I have various HTML strings to cut to 100 characters (of the stripped content, not the original) without stripping tags and without breaking HTML.

我有各种 HTML 字符串可以在不剥离标签和不破坏 HTML 的情况下剪切为 100 个字符（剥离的内容，而不是原始的）。

Original HTML string(288 characters):

原始 HTML 字符串（288 个字符）：

$content = "<div>With a <span class='spanClass'>span over here</span> and a
<div class='divClass'>nested div over <div class='nestedDivClass'>there</div>
</div> and a lot of other nested <strong><em>texts</em> and tags in the air
<span>everywhere</span>, it's a HTML taggy kind of day.</strong></div>";

Standard trim:Trim to 100 characters and HTML breaks, stripped content comes to ~40 characters:

标准修剪：修剪到 100 个字符和 HTML 中断，剥离的内容约 40 个字符：

$content = substr($content, 0, 100)."..."; /* output:
<div>With a <span class='spanClass'>span over here</span> and a
<div class='divClass'>nested div ove... */

Stripped HTML:Outputs correct character count but obviously looses formatting:

剥离的 HTML：输出正确的字符数，但显然失去了格式：

$content = substr(strip_tags($content)), 0, 100)."..."; /* output:
With a span over here and a nested div over there and a lot of other nested
texts and tags in the ai... */

Partial solution:using HTML Tidy or purifier to close off tags outputs clean HTML but 100 characters of HTML not displayed content.

部分解决方案：使用 HTML Tidy 或净化器关闭标签输出干净的 HTML，但未显示 100 个字符的 HTML 内容。

$content = substr($content, 0, 100)."...";
$tidy = new tidy; $tidy->parseString($content); $tidy->cleanRepair(); /* output:
<div>With a <span class='spanClass'>span over here</span> and a
<div class='divClass'>nested div ove</div></div>... */

Challenge:To output clean HTML and ncharacters (excluding character count of HTML elements):

挑战：输出干净的 HTML 和n 个字符（不包括 HTML 元素的字符数）：

$content = cutHTML($content, 100); /* output:
<div>With a <span class='spanClass'>span over here</span> and a
<div class='divClass'>nested div over <div class='nestedDivClass'>there</div>
</div> and a lot of other nested <strong><em>texts</em> and tags in the
ai</strong></div>...";

Similar Questions

类似问题

• How to clip HTML fragments without breaking up tags
• Cutting HTML strings without breaking HTML tags

• 如何在不分解标签的情况下剪辑 HTML 片段
• 在不破坏 HTML 标签的情况下剪切 HTML 字符串

采纳答案by code ex machina

Not amazing, but works.

并不惊人，但有效。

function html_cut($text, $max_length)
{
    $tags   = array();
    $result = "";

    $is_open   = false;
    $grab_open = false;
    $is_close  = false;
    $in_double_quotes = false;
    $in_single_quotes = false;
    $tag = "";

    $i = 0;
    $stripped = 0;

    $stripped_text = strip_tags($text);

    while ($i < strlen($text) && $stripped < strlen($stripped_text) && $stripped < $max_length)
    {
        $symbol  = $text{$i};
        $result .= $symbol;

        switch ($symbol)
        {
           case '<':
                $is_open   = true;
                $grab_open = true;
                break;

           case '"':
               if ($in_double_quotes)
                   $in_double_quotes = false;
               else
                   $in_double_quotes = true;

            break;

            case "'":
              if ($in_single_quotes)
                  $in_single_quotes = false;
              else
                  $in_single_quotes = true;

            break;

            case '/':
                if ($is_open && !$in_double_quotes && !$in_single_quotes)
                {
                    $is_close  = true;
                    $is_open   = false;
                    $grab_open = false;
                }

                break;

            case ' ':
                if ($is_open)
                    $grab_open = false;
                else
                    $stripped++;

                break;

            case '>':
                if ($is_open)
                {
                    $is_open   = false;
                    $grab_open = false;
                    array_push($tags, $tag);
                    $tag = "";
                }
                else if ($is_close)
                {
                    $is_close = false;
                    array_pop($tags);
                    $tag = "";
                }

                break;

            default:
                if ($grab_open || $is_close)
                    $tag .= $symbol;

                if (!$is_open && !$is_close)
                    $stripped++;
        }

        $i++;
    }

    while ($tags)
        $result .= "</".array_pop($tags).">";

    return $result;
}

Usage example:

用法示例：

$content = html_cut($content, 100);

回答by deceze

I'm not claiming to have invented this, but there is a very complete Text::truncate()method in CakePHPwhich does what you want:

我并没有声称自己发明了这个，但是Text::truncate()CakePHP 中有一个非常完整的方法可以满足您的需求：

function truncate($text, $length = 100, $ending = '...', $exact = true, $considerHtml = false) {
    if (is_array($ending)) {
        extract($ending);
    }
    if ($considerHtml) {
        if (mb_strlen(preg_replace('/<.*?>/', '', $text)) <= $length) {
            return $text;
        }
        $totalLength = mb_strlen($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, $length - strlen($ending));
        }
    }
    if (!$exact) {
        $spacepos = mb_strrpos($truncate, ' ');
        if (isset($spacepos)) {
            if ($considerHtml) {
                $bits = mb_substr($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 ($considerHtml) {
        foreach ($openTags as $tag) {
            $truncate .= '</'.$tag.'>';
        }
    }

    return $truncate;
}

回答by leepowers

Use PHP's DOMDocumentclass to normalize an HTML fragment:

使用 PHP 的DOMDocument类来规范化 HTML 片段：

$dom= new DOMDocument();
$dom->loadHTML('<div><p>Hello World');      
$xpath = new DOMXPath($dom);
$body = $xpath->query('/html/body');
echo($dom->saveXml($body->item(0)));

This question is similar to an earlier questionand I've copied and pasted one solution here. If the HTML is submitted by users you'll also need to filter out potential Javascript attack vectors like onmouseover="do_something_evil()"or <a href="javascript:more_evil();">...</a>. Tools like HTML Purifierwere designed to catch and solve these problems and are far more comprehensive than any code that I could post.

这个问题类似于之前的一个问题，我在这里复制并粘贴了一个解决方案。如果 HTML 是由用户提交的，您还需要过滤掉潜在的 Javascript 攻击媒介，例如onmouseover="do_something_evil()"或<a href="javascript:more_evil();">...</a>。HTML Purifier 之类的工具旨在捕获和解决这些问题，并且比我可以发布的任何代码都更全面。

回答by Ignacio Vazquez-Abrams

Use a HTML parserand stop after 100 characters of text.

使用HTML 解析器并在 100 个文本字符后停止。

回答by metrobalderas

You should use Tidy HTML. You cut the string and then you run Tidy to close the tags.

您应该使用Tidy HTML。您切断字符串，然后运行 ​​Tidy 来关闭标签。

(Credits where credits are due)

（学分到期的学分）

回答by SnakeDrak

I made another function to do it, it supports UTF-8:

我做了另一个函数来做到这一点，它支持 UTF-8：

/**
 * Limit string without break html tags.
 * Supports UTF8
 * 
 * @param string $value
 * @param int $limit Default 100
 */
function str_limit_html($value, $limit = 100)
{

    if (mb_strwidth($value, 'UTF-8') <= $limit) {
        return $value;
    }

    // Strip text with HTML tags, sum html len tags too.
    // Is there another way to do it?
    do {
        $len          = mb_strwidth($value, 'UTF-8');
        $len_stripped = mb_strwidth(strip_tags($value), 'UTF-8');
        $len_tags     = $len - $len_stripped;

        $value = mb_strimwidth($value, 0, $limit + $len_tags, '', 'UTF-8');
    } while ($len_stripped > $limit);

    // Load as HTML ignoring errors
    $dom = new DOMDocument();
    @$dom->loadHTML('<?xml encoding="utf-8" ?>'.$value, LIBXML_HTML_NODEFDTD);

    // Fix the html errors
    $value = $dom->saveHtml($dom->getElementsByTagName('body')->item(0));

    // Remove body tag
    $value = mb_strimwidth($value, 6, mb_strwidth($value, 'UTF-8') - 13, '', 'UTF-8'); // <body> and </body>
    // Remove empty tags
    return preg_replace('/<(\w+)\b(?:\s+[\w\-.:]+(?:\s*=\s*(?:"[^"]*"|"[^"]*"|[\w\-.:]+))?)*\s*\/?>\s*<\/\s*>/', '', $value);
}

SEE DEMO.

见演示。

I recommend use html_entity_decodeat the start of function, so it preserves the UTF-8 characters:

我建议html_entity_decode在函数的开头使用，因此它保留了 UTF-8 字符：

 $value = html_entity_decode($value);

回答by Chuck Burgess

Regardless of the 100 count issues you state at the beginning, you indicate in the challenge the following:

无论您在开始时陈述的 100 个计数问题如何，您都在挑战中指出以下内容：

• output the character count of strip_tags (the number of characters in the actual displayed text of the HTML)
• retain HTML formatting close
• any unfinished HTML tag

• 输出strip_tags的字符数（HTML实际显示文本的字符数）
• 保留 HTML 格式关闭
• 任何未完成的 HTML 标签

Here is my proposal: Bascially, I parse through each character counting as I go. I make sure NOT to count any characters in any HTML tag. I also check at the end to make sure I am not in the middle of a word when I stop. Once I stop, I back track to the first available SPACE or > as a stopping point.

这是我的建议：基本上，我边走边解析每个字符。我确保不计算任何 HTML 标签中的任何字符。我还在最后检查以确保当我停下来时我不在一个单词的中间。一旦我停下来，我就会回到第一个可用的 SPACE 或 > 作为停止点。

$position = 0;
$length = strlen($content)-1;

// process the content putting each 100 character section into an array
while($position < $length)
{
    $next_position = get_position($content, $position, 100);
    $data[] = substr($content, $position, $next_position);
    $position = $next_position;
}

// show the array
print_r($data);

function get_position($content, $position, $chars = 100)
{
    $count = 0;
    // count to 100 characters skipping over all of the HTML
    while($count <> $chars){
        $char = substr($content, $position, 1); 
        if($char == '<'){
            do{
                $position++;
                $char = substr($content, $position, 1);
            } while($char !== '>');
            $position++;
            $char = substr($content, $position, 1);
        }
        $count++;
        $position++;
    }
echo $count."\n";
    // find out where there is a logical break before 100 characters
    $data = substr($content, 0, $position);

    $space = strrpos($data, " ");
    $tag = strrpos($data, ">");

    // return the position of the logical break
    if($space > $tag)
    {
        return $space;
    } else {
        return $tag;
    }  
}

This will also count the return codes etc. Considering they will take space, I have not removed them.

这也将计算返回代码等。考虑到它们会占用空间，我没有删除它们。

回答by wakel

Here is a function I'm using in one of my projects. It's based on DOMDocument, works with HTML5 and is about 2x faster than other solutions I've tried (at least on my machine, 0.22 ms vs 0.43 ms using html_cut($text, $max_length)from the top answer on a 500 text-node-characters string with a limit of 400).

这是我在我的一个项目中使用的一个函数。它基于 DOMDocument，适用于 HTML5，比我尝试过的其他解决方案快约 2 倍（至少在我的机器上，0.22 毫秒 vs 0.43 毫秒，使用html_cut($text, $max_length)500 个文本节点字符字符串的顶部答案，限制为400）。

function cut_html ($html, $limit) {
    $dom = new DOMDocument();
    $dom->loadHTML(mb_convert_encoding("<div>{$html}</div>", "HTML-ENTITIES", "UTF-8"), LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD);
    cut_html_recursive($dom->documentElement, $limit);
    return substr($dom->saveHTML($dom->documentElement), 5, -6);
}

function cut_html_recursive ($element, $limit) {
    if($limit > 0) {
        if($element->nodeType == 3) {
            $limit -= strlen($element->nodeValue);
            if($limit < 0) {
                $element->nodeValue = substr($element->nodeValue, 0, strlen($element->nodeValue) + $limit);
            }
        }
        else {
            for($i = 0; $i < $element->childNodes->length; $i++) {
                if($limit > 0) {
                    $limit = cut_html_recursive($element->childNodes->item($i), $limit);
                }
                else {
                    $element->removeChild($element->childNodes->item($i));
                    $i--;
                }
            }
        }
    }
    return $limit;
}

回答by Muhammad Umar

try this function

试试这个功能

// trim the string function
function trim_word($text, $length, $startPoint=0, $allowedTags=""){
    $text = html_entity_decode(htmlspecialchars_decode($text));
    $text = strip_tags($text, $allowedTags);
    return $text = substr($text, $startPoint, $length);
}

and

和

echo trim_word("<h2 class='zzzz'>abcasdsdasasdas</h2>","6");

回答by Kubee

Here is my try at the cutter. Maybe you guys can catch some bugs. The problem, i found with the other parsers, is that they don't close tags properly and they cut in the middle of a word (blah)

这是我在刀具上的尝试。也许你们可以抓住一些错误。我在其他解析器中发现的问题是，它们没有正确关闭标签，而是在单词中间切掉了（废话）

function cutHTML($string, $length, $patternsReplace = false) {
    $i = 0;
    $count = 0;
    $isParagraphCut = false;
    $htmlOpen = false;
    $openTag = false;
    $tagsStack = array();

    while ($i < strlen($string)) {
        $char = substr($string, $i, 1);
        if ($count >= $length) {
            $isParagraphCut = true;
            break;
        }

        if ($htmlOpen) {
            if ($char === ">") {
                $htmlOpen = false;
            }
        } else {
            if ($char === "<") {
                $j = $i;
                $char = substr($string, $j, 1);

                while ($j < strlen($string)) {
                    if($char === '/'){
                        $i++;
                        break;
                    }
                    elseif ($char === ' ') {
                        $tagsStack[] = substr($string, $i, $j);
                    }
                    $j++;
                }
                $htmlOpen = true;
            }
        }

        if (!$htmlOpen && $char != ">") {
            $count++;
        }

        $i++;
    }

    if ($isParagraphCut) {
        $j = $i;
        while ($j > 0) {
            $char = substr($string, $j, 1);
            if ($char === " " || $char === ";" || $char === "." || $char === "," || $char === "<" || $char === "(" || $char === "[") {
                break;
            } else if ($char === ">") {
                $j++;
                break;
            }
            $j--;
        }
        $string = substr($string, 0, $j);
        foreach($tagsStack as $tag){
            $tag = strtolower($tag);
            if($tag !== "img" && $tag !== "br"){
                $string .= "</$tag>";
            }
        }
        $string .= "...";
    }

    if ($patternsReplace) {
        foreach ($patternsReplace as $value) {
            if (isset($value['pattern']) && isset($value["replace"])) {
                $string = preg_replace($value["pattern"], $value["replace"], $string);
            }
        }
    }
    return $string;
}