如何用链接替换 ​​HTML 文本中的词汇表术语？

Question

我想运行str_replace 或preg_replace，它在我的$content 中查找某些单词（在$glossary_terms 中找到）并将它们替换为链接（如<a href="/glossary/initial/term">term</a>）。

但是，$content 是完整的 HTML，我的链接/图像也受到影响，这不是我想要的。

$content 的一个例子是：

<div id="attachment_542" class="wp-caption alignleft" style="width: 135px"><a href="http://www.seriouslyfish.com/dev/wp-content/uploads/2011/12/Amazonas-English-1.jpg"><img class="size-thumbnail wp-image-542" title="Amazonas English" src="http://www.seriouslyfish.com/dev/wp-content/uploads/2011/12/Amazonas-English-1-288x381.jpg" alt="Amazonas English" width="125" height="165" /></a><p class="wp-caption-text">Amazonas Magazine - now in English!</p></div>
<p>Edited by Hans-Georg Evers, the magazine &#8216;Amazonas&#8217; has been widely-regarded as among the finest regular publications in the hobby since its launch in 2005, an impressive achievment considering it&#8217;s only been published in German to date. The long-awaited English version is just about to launch, and we think a subscription should be top of any serious fishkeeper&#8217;s Xmas list&#8230;</p>
<p>The magazine is published in a bi-monthly basis and the English version launches with the January/February 2012 issue with distributors already organised in the United States, Canada, the United Kingdom, South Africa, Australia, and New Zealand. There are also mobile apps availablen which allow digital subscribers to read on portable devices.</p>
<p>It&#8217;s fair to say that there currently exists no better publication for dedicated hobbyists with each issue featuring cutting-edge articles on fishes, invertebrates, aquatic plants, field trips to tropical destinations plus the latest in husbandry and breeding breakthroughs by expert aquarists, all accompanied by excellent photography throughout.</p>
<p>U.S. residents can subscribe to the printed edition for just $29 USD per year, which also includes a free digital subscription, with the same offer available to Canadian readers for $41 USD or overseas subscribers for $49 USD. Please see the <a href="http://www.amazonasmagazine.com/">Amazonas website</a> for further information and a sample digital issue!</p>
<p>Alternatively, subscribe directly to the print version <a href="https://www.amazonascustomerservice.com/subscribe/index2.php">here</a> or digital version <a href="https://www.amazonascustomerservice.com/subscribe/digital.php">here</a>. Just gonna add this to the end of the post so I can do some testing.</p>

我遇到了this link，但我不确定这种方法是否适用于嵌套 HTML。

我有什么办法可以str_replace 或preg_replace 内容仅包含在<p> 标记中；排除任何嵌套的<a>、<img> 或<h1/2/3/4/5> 标签？

提前致谢，

Answer 1

“按部就班的解决方案”是这样的：

<?php

$html = "<your HTML string>";
$glossary_terms = array('fishes', 'invertebrates', 'aquatic plants');

$dom = new DOMDocument;
$dom->loadHTML($html);

dom_link_glossary($dom, $glossary_terms);

echo $dom->saveHTML();

// wraps all occurrences of the glossary terms in links
function dom_link_glossary(&$document, &$glossary) {
  $xpath   = new DOMXPath($document);
  $urls    = array();
  $pattern = array();

  // build a normalized lookup (case-insensitive, whitespace-agnostic)
  foreach ($glossary as $term) {
    $term_norm = preg_replace('/\s+/', ' ', strtoupper(trim($term)));
    $pattern[] = preg_replace('/ /', '\\s+', preg_quote($term_norm));
    $urls[$term_norm] = '/glossary/initial/' . rawurlencode($term);
  }

  $pattern  = '/\b(' . implode('|', $pattern) . ')\b/i';
  $text_nodes = $xpath->query('//text()[not(ancestor::a)]');

  foreach($text_nodes as $original_node) {
    $text     = $original_node->nodeValue;
    $hitcount = preg_match_all($pattern, $text, $matches, PREG_OFFSET_CAPTURE);

    if ($hitcount == 0) continue;

    $offset   = 0;
    $parent   = $original_node->parentNode;
    $refnode  = $original_node->nextSibling;

    $parent->removeChild($original_node);

    foreach ($matches[0] as $i => $match) {
      $term_txt = $match[0];
      $term_pos = $match[1];
      $term_norm = preg_replace('/\s+/', ' ', strtoupper($term_txt));

      // insert any text before the term instance
      $prefix = substr($text, $offset, $term_pos - $offset);
      $parent->insertBefore($document->createTextNode($prefix), $refnode);

      // insert the actual term instance as a link
      $link = $document->createElement("a", $term_txt);
      $link->setAttribute("href", $urls[$term_norm]);
      $parent->insertBefore($link, $refnode);

      $offset = $term_pos + strlen($term_txt);

      if ($i == $hitcount - 1) {  // last match, append remaining text
        $suffix = substr($text, $offset);
        $parent->insertBefore($document->createTextNode($suffix), $refnode);
      }
    }
  }
}
?>

dom_link_glossary() 的工作原理如下：

• 它将词汇表术语（修剪、大写、空白）标准化，并构建一个查找数组和一个匹配所有术语的正则表达式模式。
• 它使用 XPath 来查找尚未成为链接一部分的所有文本节点。无论嵌套深度如何，都会返回文本节点（即我们不需要递归）。我使用\b 来防止部分匹配。
• 对于每个包含术语的文本节点：
  • 删除原文节点($parent->removeChild())
  • 现在新节点被创建并插入到 DOM 中：文本节点用于词汇表术语之前（或之后）的任何内容，元素节点 (<a>) 用于实际术语表术语。

解决方案保留原始大小写和空白，因此

• term 将变为 <a href="/glossary/initial/term">term</a>
• Term 将变为 <a href="/glossary/initial/term">Term</a>
• Foo Bar 将变为 <a href="/glossary/initial/foo%20bar">Foo Bar</a>。 HTML 中多余的空格或换行符不会破坏机制。

请注意，在纯文本节点值上使用正则表达式是完全可以的。不能在完整的 HTML 上使用正则表达式。

我建议将词汇表术语与其各自的 URL 放在一个数组中，而不是在函数中计算 URL。这样你就可以让多个词条指向同一个 URL。

Answer 2

你可以试试这个：

$content = preg_replace('/(<p\sclass=\"wp\-caption\-text\">)[^<]+(<\/p>)/i', '', $content);