PHP: Filter all codes except scripts and images from MY site?

Lets say a member left a comment.

Hi! Look at these cars.
<img src="http://www.mysite.com/possiblefolder/possiblesub/image.jpg"></img>
<img src="http://othersite.com/possiblefolder/possiblesub/image.jpg"></img>
<img src="http://www.mysite.otherside.com/possiblefolder/image.jpg"></img>
Which is your favorite?

I want the results to come up as:

Hi! Look at these cars.
<img src="http://www.mysite.com/possiblefolder/possiblesub/image.jpg"></img>
http://othersite.com/possiblefolder/possiblesub开发者_运维技巧/image.jpg  
http://www.mysite.otherside.com/possiblefolder/possiblesub/image.jpg  
Which is your favorite?

I want to filter all codes except images and scripts coming from my site. Anyone got any ideas?

Hope this helps

<(\w+).+src=[\x22|'](?![^\x22']+mysite\.com[^\x22']+)([^\x22']+)[\x22|'].*>(?:</\1>)?

Group 1 is the tag used and group 2 is the "src" value so you can do a replace.

In Browser Demo

In most reasonable cases and in particular in your examples, this will work:

$new_comment = preg_replace('%<img.*?\ssrc="(http://(?!www.mysite.com).*?)".*?>.*?</img>%', '\1', $old_comment);

It will give the result you describe.

If it's not proper XHTML, run it through Tidy. If it's already clean XHTML, skip this part

$config = array('output-xhtml'   => true);
$tidy = new tidy();
$html = $tidy->repareString($html, $config, 'utf8');

Now, having clean XHTML you can use XPath:

$xhtml = new SimpleXMLElement($html);
foreach ($xhtml->xpath('//*/img') as $img_parent) {
   if(!(strpos($img_parent->img->src, 'http://www.mysite.com/') === 0)) {
     $img_parent->img = new SimpleXMLElement($img_parent->img->src);
   }
}
$cleaned_html = $xhtml->asXML();

You can use PHP strip_tags() to strip all HTML tags out from user-comment (highly recommended), also you need to implement some script code such as BBCode on PHPbb forums, etc...

[img]possibleimgdir/someimage.jpg[/img]

later search for [img] and [/img], append your root URL in front of content found between tags (example. http://www.mysite.com/possibleimgdir/someimage.jpg), check if file exists and then create HTML IMG tags for that SRC property if it is valid...

That's just one of possible ideas!

You could do it with a jQuery oneliner:

$('img:not(src^="http://www.mysite.com/")').hide()