PHP replace string help...

Question

i am designing a site with a comment system and i would like a twitter like reply system.

The if the user puts @a_registered_username i would like it to become a link to the user's profile.

i think preg_replace is the function needed for this.

$ALL_USERS_ROW *['USERNAME'] is the database query array for all the users and ['USERNAME'] is the username row.

$content is the comment containing the @username

i think this should not be very hard to solve for someone who is good at php.

Does anybody have any idea how to do it?

Answer 1

You want it to go through the text and get it, here is a good starting point:

$txt='this is some text @seanja';

$re1='.*?'; # Non-greedy match on filler
$re2='(@)'; # Any Single Character 1
$re3='((?:[a-z][a-z]+))';   # Word 1

if ($c=preg_match_all ("/".$re1.$re2.$re3."/is", $txt, $matches))
{
      $c1=$matches[1][0];
      $word1=$matches[2][0]; //this is the one you want to replace with a link
      print "($c1) ($word1) \n";
}

Generated with:

http://www.txt2re.com/index-php.php3?s=this%20is%20some%20text%20@seanja&-40&1

[edit]

Actually, if you go here ( http://www.gskinner.com/RegExr/ ), and search for twitter in the community tab on the right, you will find a couple of really good solutions for this exact problem:

$mystring = 'hello @seanja @bilbobaggins [email protected] and @slartibartfast';
$regex = '/(?<=@)((\w+))(\s)/g';
$replace = '<a href='http://twitter.com/$1' target="_blank">$1</a>$3';
preg_replace($regex, $replace, $myString);

Answer 2

$content = preg_replace( "/\b@(\w+)\b/", "http://twitter.com/$1", $content );

should work, but I can't get the word boundary matches to work in my test ... maybe dependent on the regex library used in versions of PHP

 $content = preg_replace( "/(^|\W)@(\w+)(\W|$)/", "$1http://twitter.com/$2$3", $content );

is tested and does work

Answer 3

$str = preg_replace('~(?<!\w)@(\w+)\b~', 'http://twitter.com/$1', $str);

Does not match emails. Does not match any spaces around it.