Match and replace with the captured/matched characters - php

Question

I currently have a code that finds and replaces urls into complete html links. It works fine but now i need to update it so that if there is image url then it should convert it into a html img tag and display it. Function im using now is...
function auto_link_text($text) {
$pattern = '#\b(([\w-]+://?|www[.])[^\s()<>]+(?:\([\w\d]+\)|([^[:punct:]\s]|/)))#';
$callback = create_function('$matches', '
$url = array_shift($matches);
$url_parts = parse_url($url);
return sprintf(\'<a rel="nowfollow" target="_blank" href="%s">%s</a>\', $url, $url);
');
return preg_replace_callback($pattern, $callback, $text);
}
Got it from...
How to add anchor tag to a URL from text input
Here is an example of the text i would to it to go through...
asdf
http://google.com/
asfd
http://yahoo.com/logo.jpg
http://www.apple.com/sdfsd.php?page_id=13&id=18210&status=active#1
http://youtube.com/logo.png
like it updated function to output...
asdf
<a rel="nowfollow" target="_blank" href="http://google.com/">http://google.com/</a>
asfd
<img src="http://yahoo.com/logo.jpg" class="example">
<a rel="nowfollow" target="_blank" href="http://www.apple.com/sdfsd.php?page_id=13&id=18210&status=active#1">http://www.apple.com/sdfsd.php?page_id=13&id=18210&status=active#1</a>
<img src="http://youtube.com/logo.png" class="example">
Big thanks in advance!

Answer 1

You can use this for example:
function create_anchor_tag($url, $text = false) {
if ($text===false) $text = $url;
return '<a rel="no-follow" target="_blank" href="' . $url . '">'
. $text . '</a>';
}
function create_image_tag($url) {
return '<img src="' . $url . '"/>';
}
function auto_link_text($text) {
$pattern = '~\b(?:(?:ht|f)tps?://|www\.)\S+(?<=[\PP?])~i';
$callback = function ($m) {
$img_ext = array('jpg', 'jpeg', 'gif', 'png');
$path = parse_url($m[0], PHP_URL_PATH);
$ext = substr(strrchr($path, '.'), 1);
if (in_array(strtolower($ext), $img_ext))
return create_image_tag($m[0]);
return create_anchor_tag($m[0]);
};
return preg_replace_callback($pattern, $callback, $text);
}
I used several functions to make it more clea[rn], but you can easily adapt it as you like.

Answer 2

Here is the nice post about the best suitable regex pattern for valid URL. I picked one from there to group all the URLs.
Online demo
Steps to follow:
simply extract the url.
put a check on the url and based on your own logic substitute the tag as shown in demo.
sample code: (get all the valid urls in groups. get it from index 1)
$re = "/(([A-Za-z]{3,9}:(?:\\/\\/)?(?:[-;:&=\\+\\$,\\w]+#)?[A-Za-z0-9.-]+|(?:www.|[-;:&=\\+\\$,\\w]+#)[A-Za-z0-9.-]+)((?:\\/[\\+~%\\/.\\w-_]*)?\\??(?:[-\\+=&;%#.\\w_]*)#?(?:[\\w]*))?)/";
$str = "...";
preg_match_all($re, $str, $matches);
sample code: (substitute anchor tag (or what ever you want to add))
$re = "/(([A-Za-z]{3,9}:(?:\\/\\/)?(?:[-;:&=\\+\\$,\\w]+#)?[A-Za-z0-9.-]+|(?:www.|[-;:&=\\+\\$,\\w]+#)[A-Za-z0-9.-]+)((?:\\/[\\+~%\\/.\\w-_]*)?\\??(?:[-\\+=&;%#.\\w_]*)#?(?:[\\w]*))?)/";
$str = "...";
$subst = '$1';
$result = preg_replace($re, $subst, $str);