how to add attribute rel nofollow on tag a with regex

Question

how to add attribute rel nofollow on tag a with regex

Sample:

<a href="http://www.test.org/5521" rel="follow">test1</a>
<a href="http://www.test.org/5522" rel="external">test1</a>
<a href="http://www.test.org/5523">test1</a>

To:

<a href="http://www.test.org/5521" rel="nofollow">test1</a>
<a href="http://www.test.org/5522" rel="nofollow">test1</a>
<a href="http://www.test.org/5523" rel="nofollow">test1</a>

Answer 1

Using a DOM parser would be a more natural solution here:

$html = <<<STR
<html><body>
<a href="http://www.test.org/5521" rel="follow">test1</a><br/>
<a href="http://www.test.org/5522" rel="external">test1</a><br/>
<a href="http://www.test.org/5523">test1</a>
</body></html>
STR;

$dom = new DOMDocument('1.0', 'UTF-8');
$dom->loadHTML($html, LIBXML_HTML_NOIMPLIED | LIBXML_HTML_NODEFDTD);
$links = $dom->getElementsByTagName("a");

foreach($links as $link) { 
   $link->setAttribute('rel', 'nofollow');
}

echo $dom->saveHTML();

See the PHP demo

With $links = $dom->getElementsByTagName("a"); , you get all the a nodes, and with $link->setAttribute('rel', 'nofollow'); , you set the rel attribute regardless whether it was present or not.

Output:

<html><body>
<a href="http://www.test.org/5521" rel="nofollow">test1</a><br>
<a href="http://www.test.org/5522" rel="nofollow">test1</a><br>
<a href="http://www.test.org/5523" rel="nofollow">test1</a>
</body></html>

Answer 2

Step1: Remove All Rel from tag a

$result = preg_replace('@rel="(.*)"@U', '', $html);

Step2: Add Rel Nofollow on taf a

$result = preg_replace('@<a(.*)>@U', '<a$1 rel="nofollow">', $result);

how to add attribute rel nofollow on tag a with regex

Question

2 answers

solution1
2 2017-05-08 07:54:53

solution2
1 2017-05-08 07:33:04

how to add attribute rel nofollow on tag a with regex

Question

2 answers

solution1 2 2017-05-08 07:54:53

solution2 1 2017-05-08 07:33:04

solution1
2 2017-05-08 07:54:53

solution2
1 2017-05-08 07:33:04