Mini parsing script

[astropirit]

Greetings all

i am trying to write a templating engine and i require a simple conditional statement to be part of it.

the syntax for the statement would go something like this:

{-IF UserOnline DO 'this will be printed out! and this {-UserName-}' ''-}

 

what i would like to do is find a statement such as that and get the argument in this case "UserOnline" and if it returns true then it will replace the while thing  with what is inside the single quotes ''.

i just need help with the ragex part. i dont know how i would test if there is another "{-" inside it should look for two "-}" before ending the search.

so far i have this but it definatly isnt working

 

$prepat = '([A-Za-z0-9(\<(/?[^\>]+)\>)(\{\-([A-Za-z0-9-]+)\-\})-]+)';
$pattern = '`' .$this->LEFT_DELIMITER ."\s*" ."IF" ."\s*" ."UserOnline"."\s*" ."DO" ."\s*'\s*" .$prepat ."\s*'\s*" .$this->RIGHT_DELIMITER .'`i';
        

 

any help would be greatly apreciated.