正则表达式条<a>包含特定href值的标签

问题描述：

I am not good at regex.

I got this string with some html <a> tags and i need to strip some of them out, but only <a> tags containing a certain value in the "href" attribut (mysite.com).

I still need to keep the link text, like the php function strip_tags($string, "<a>")

Here is what I got so far.:

/<a href=["\']?(http:\/\/mysite.com[^"\'\s>]+)["\'\s>]?/i

This is also working, but the problem is that I can't get the "text" in fx. <a href="http://mysite.com/testing/something">"text"</a>

So the input.:

Lorem ipsum <a href="http://mysite.com/testing/something">dolor</a> sit amet, <a href="http://keepingThisLink.com">consectetur</a> adipiscing elit. Duis dignissim <a href="http://mysite.com/testing">golor</a> vitae turpis fermentum tincidunt.

Should output.:

Lorem ipsum dolor sit amet, <a href="http://keepingThisLink.com">consectetur</a> adipiscing elit. Duis dignissim golor vitae turpis fermentum tincidunt.

我不擅长正则表达式。 p>

我有一些字符串 html ＆lt; a＆gt; code>标签，我需要删除其中一些标签，但只有＆lt; a＆gt; code>标签在“href”attribut中包含一定值（mysite。 COM）。 p>

我仍然需要保留链接文本，例如php函数 strip_tags（$ string，“＆lt; a＆gt;”） code> p> \ n

这是我到目前为止所得到的： p> nn


  /<a href = [“\']？（http：\ / \ / mysite.com [  ^“\'\ s＆gt;] +）[”\'\ s＆gt;]？/ i 
  code>  pre> 
 
 这也有效，但问题是我可以 在fx中得到“text”。＆lt; a href =“http://mysite.com/testing/something”＆gt;“text”＆lt; / a＆gt;  code>  p> \  n 
 
 所以输入。： strong>  p> 
nn 
  Lorem ipsum＆lt; a href =“http://mysite.com/testing/  “＆gt; dolor＆lt; / a＆gt;坐下来，＆lt; a href =”http://keepingThisLink.com“＆gt; consectetur＆lt; / a＆gt; adipiscing elit.Duis dignissim＆lt; a href =”http：// mysite。  com / testing“＆gt; golor＆lt; / a＆gt; vitae turpis fermentum tincidunt。
  code>  pre> 
 
  应该输出。： strong> 
  
   Lorem ipsum dolor sit amet，＆lt; a href =“http://keepingThisLink.com”＆gt; consectetur＆lt; / a＆gt; adipiscing elit.Duis dignissim golor vitae turpis fermentum tincidunt。
  码 >  pre> 
  div>

答

Here's a more reliable, DOM-based approach:

<?php

$a = 'Lorem ipsum <a href="http://mysite.com/testing/something">dolor</a> sit amet, <a href="http://keepingThisLink.com">consectetur</a> adipiscing elit. Duis dignissim <a href="http://mysite.com/testing">golor</a> vitae turpis fermentum tincidunt.';

$domd = new DOMDocument();
libxml_use_internal_errors(true);
$domd->loadHTML($a);

$domx = new DOMXPath($domd);
foreach ($domx->query("//a") as $link) {
    $href = $link->getAttribute("href");
    if ($href === "http://keepingThisLink.com") {
        continue;
    }

    $text = $domd->createTextNode($link->nodeValue);

    $link->parentNode->replaceChild($text, $link);
}

//unfortunately saveHTML adds doctype and a few unneccessary tags    
var_dump(preg_replace('/^<!DOCTYPE.+?>/', '', str_replace( array('<html>', '</html>', '<body>', '</body>'), array('', '', '', ''), $domd->saveHTML())));

the output is:

string(161) "
<p>Lorem ipsum dolor sit amet, <a href="http://keepingThisLink.com">consectetur</a> adipiscing elit. Duis dignissim golor vitae turpis fermentum tincidunt.</p>
"

答

You might want to look at PHP's DOM classes, they'll let you locate all the hyperlinks within a HTML document, get their href attributes and update/remove them in a way that's far more robust than attempting to do it with regex.

(Please note that the following example is "from the hip" and hasn't been tested)

$dom = new DOMDocument ();

// Load from a file
$dom -> load ('/path/to/my/file.html');

// Or load a HTML string
$dom -> loadHTML ($string);

// Or load an XHTML string as XML
$dom -> loadXML ($string);

// Find all the hyperlinks
if ($nodes = $dom -> getElementsByTagName ('a'))
{
    foreach ($nodes as $node)
    {
        var_dump ($node -> getAttribute ('href'));
    }
}

正则表达式条包含特定href值的标签

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