Processing entities to linkify a tweet

LinkifyEntities.php

<?php
public function getLinkifiedText(){
    $allEntities = array();
    foreach(json_decode($this->entities) as $entityGroup){
        foreach($entityGroup as $entity){
            $allEntities[$entity->indices[0]] = $entity;
        }
    }
    krsort($allEntities);
    $text = $this->text;
    foreach($allEntities as $entity){
        if(isset($entity->display_url)){
            $link = '<a href="'. $entity->url .'" class="tweet-entity" target="_Blank">'.$entity->display_url.'</a>';
        }
        else if(isset($entity->screen_name)){
            $link = '<a href="http://www.twitter.com/'.$entity->screen_name.'" class="user-mention-entity" target="_Blank">@'.$entity->screen_name.'</a>';
        }
        else{
            $link = '<a href="http://www.twitter.com/#!/search/realtime/'. $entity->text .'" class="hashtag-entity" target="_Blank">'.$entity->text.'</a>';
        }
        $text =substr_replace($text, $link, $entity->indices[0], $entity->indices[1] - $entity->indices[0]);
    }
    return $text;
}