用正则表达式包装<a>标签中的链接

Question

我需要在文本中使用带有正则表达式的"a"标记包装文本中的所有链接,除了已经包装的那些

所以我有文字:

Some text with html here
http://www.somelink.html
http://www.somelink.com/view/?id=95
<a href="http://anotherlink.html">http://anotherlink.html</a>
<a href="http://anotherlink.html">Title</a>

我需要得到什么:

Some text with html here
<a href="http://www.somelink.html">http://www.somelink.html</a> <a href="http://www.somelink.com/view/?id=2495">http://www.somelink.com/view/?id=95</a>
<a href="http://anotherlink.html">http://anotherlink.html</a>
<a href="http://anotherlink.html">Title</a>

我可以使用此表达式匹配链接:

(?:(?:https?|ftp):\/\/|www.)[-a-z0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|]

但它也匹配已经在"a"标签中的thouse

Answer 1

为了可靠性，我会拆分<a>标签（包括子内容）和其他标签（不包括子内容），例如：

$bits = preg_split('/(<a(?:\s+[^>]*)?>.*?<\/a>|<[a-z][^>]*>)/is', $content, null, PREG_SPLIT_DELIM_CAPTURE);

$reconstructed = '';

foreach ($bits as $bit) {
  if (strpos($bit, '<') !== 0) {//not inside an <a> or within < and > so check for urls
    $bit = link_urls($bit);
  }
  $reconstructed .= $bit;
}