PHP: How to use the Twitter API's data to convert URLs, mentions, and hastags in tweets to links?

Question

I\'m really stumped on how Twitter expects users of its API to convert the plaintext tweets it sends to properly linked HTML.

Here\'s the deal: Twitter\'s JSON API sends

Answer 1

Here is an updated answer that works with Twitter's new Extended Mode. It combines the answer by @vita10gy and the comment by @Hugo (to make it utf8 compatible), with a few minor tweaks to work with the new api values.

function utf8_substr_replace($original, $replacement, $position, $length) {
    $startString = mb_substr($original, 0, $position, "UTF-8");
    $endString = mb_substr($original, $position + $length, mb_strlen($original), "UTF-8");
    $out = $startString . $replacement . $endString;
    return $out;
}

function json_tweet_text_to_HTML($tweet, $links=true, $users=true, $hashtags=true) {
    // Media urls can show up on the end of the full_text tweet, but twitter doesn't index that url. 
    // The display_text_range indexes show the actual tweet text length.
    // Cut the string off at the end to get rid of this unindexed url.
    $return = mb_substr($tweet->full_text, $tweet->display_text_range[0],$tweet->display_text_range[1]);
    $entities = array();

    if($links && is_array($tweet->entities->urls))
    {
        foreach($tweet->entities->urls as $e)
        {
            $temp["start"] = $e->indices[0];
            $temp["end"] = $e->indices[1];
            $temp["replacement"] = " ".$e->display_url."";
            $entities[] = $temp;
        }
    }
    if($users && is_array($tweet->entities->user_mentions))
    {
        foreach($tweet->entities->user_mentions as $e)
        {
            $temp["start"] = $e->indices[0];
            $temp["end"] = $e->indices[1];
            $temp["replacement"] = " @".$e->screen_name."";
            $entities[] = $temp;
        }
    }
    if($hashtags && is_array($tweet->entities->hashtags))
    {
        foreach($tweet->entities->hashtags as $e)
        {
            $temp["start"] = $e->indices[0];
            $temp["end"] = $e->indices[1];
            $temp["replacement"] = " #".$e->text."";
            $entities[] = $temp;
        }
    }

    usort($entities, function($a,$b){return($b["start"]-$a["start"]);});


    foreach($entities as $item)
    {
        $return =  utf8_substr_replace($return, $item["replacement"], $item["start"], $item["end"] - $item["start"]);
    }

    return($return);
}