regex for a link
I have a text with 'a' tags there. I have to add some new tags and attributes.
It looks like this:
'Some test <a href="site">here</a>. Yet <a href="site2">another</a> test.'
Now I have to get:
'Some test <noindex><a rel="nofollow" href="site">here&开发者_如何学Clt;/a></noindex>.'
'Yet <noindex><a rel="nofollow" href="site2">another</a></noindex> test.'
Any fast ways to do that with php? Thanks.
Something like this would cover most real world cases:
$text = 'Some test <a href="site">here</a>. Yet <a href="site2">another</a> test.';
$regex = '%(<a\s)(.*?</a>)%i';
$replacement = '<noindex>$1rel="nofollow" $2</noindex>';
preg_replace($regex, $replacement, $text);
Bearing in mind that HTML parsing with regular expression is a bad idea (you should use something like DOMDocument instead), this should do it:
$str = 'Some test <a href="site">here</a>. Yet <a href="site2">another</a> test.';
echo preg_replace('/<a(.+?)<\/a>/', '<noindex><a$1</a></noindex>', $str);
// Some test <noindex><a href="site">here</a></noindex>. Yet <noindex><a href="site2">another</a></noindex> test.
Just wanted to give the DOMDocument (docs) version, since the conventional wisdom says "Don't use RegEx on HTML!!". Well, that's a fine thing to say, but then what!? Well, here you go:
// create a new DOMDocument
$doc = new DOMDocument();
// load the string into the DOM
$doc->loadHTML('Some test <a href="site">here</a>. Yet <a href="site2">another</a> test.');
// since we are working with HTML fragments here, remove <!DOCTYPE
$doc->removeChild($doc->firstChild);
// likewise remove <html><body></body></html>
$doc->replaceChild($doc->firstChild->firstChild->firstChild, $doc->firstChild);
//Loop through each <a> tag in the dom and wrap it with <noindex>
foreach($doc->getElementsByTagName('a') as $link) {
$parent = $link->parentNode;
$ni = $doc->createElement('noindex');
$ni->appendChild($link->cloneNode(true));
$parent->replaceChild($ni, $link);
}
echo $doc->saveHTML();
Check it out here: http://codepad.org/ANi93sBj
$string = preg_replace('~<a.*?href=(.*?)>(.*?)</a>~msi', '<noindex><a rel="nofollow" href=$1>$2</a></noindex>', $html);
加载中,请稍侯......
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