Preg_Replace and Capture Value? PHP

Question

I'm building a filter plugin in Wordpress and I'm replacing some plugin specific tags with bits of html.

Example: [VIDEO ID=12] will be replaced via preg_replaced in this function

function display_video($text){

   $pattern = '/\[VIDEO ID\=\d+\]/';

   $text=preg_replace($pattern,get_video_block($id),$text);

   return $text;
}

I'm not exactly sure how to make sure I supply the correct ($id) param to my get_video_block function for each replacement occurrence.

There's no real loop going on other than inside the preg_replace function so, how would I supply that value?

Thoughts?

EDIT (get_video_block) function:

function get_video_block($id){
    global $wpdb;
    $wpdb->show_errors();
    $table_name = $wpdb->prefix . "video_manager";
    $query = "SELECT * FROM " . $table_name . " WHERE `index` = '$id'"; 
    $results = $wpdb->get_results($query, ARRAY_A);

    $results = $results[0];

    $returnString = '<div class="vidBlock">';
        $returnString .= $results['embed_code'];

        $returnString .= '<div class="voteBar">';
            $returnString .= $results['vote_text'];
            $returnString .= '<input type="button" value="YES" class="voteButton">';
            $returnString .= '<input type="button" value="NO" class="voteButton">';
        $returnString .= '</div>';

        $returnString .= $results['title'] . '<br>';
        $returnString .= $results['description'] . '<br>';

    $returnString .= '</div>';

    return $returnString;

}

Answer 1

You can use preg_replace_callback() for that purpose. You'll also need to wrap \d+ in ( parentheses ) so it can be captured and used in the callback function.

function display_video($text) {
    $callback = create_function('$matches', 'return get_video_block($matches[1])');
    return preg_replace_callback('/\[VIDEO ID\=(\d+)\]/', $callback, $text);
}

Note that $matches[1] is used because $matches[0] contains the entire string matched by the regular expression.

Erwin's comment may be of use to you — WordPress has a shortcode API that manages parsing of shortcodes for you, so you can concentrate on dealing with what you want to do with the shortcode attributes.