AV - Vote Button (ajax)

<?php
/*
Plugin Name: AV - Vote for Standalone Document
Plugin URI: http://pippinsplugins.com/write-a-love-it-plugin-with-ajax/
Description: AJAX voting on posts/pages
Version: 1.0
Author: Alex Vallejo
Author URI:
*/

if(!defined('DOC_VOTE_BASE_DIR')){
    define('DOC_VOTE_BASE_DIR', dirname(__FILE__));
}
if(!defined('DOC_VOTE_BASE_URL')){
    define('DOC_VOTE_BASE_URL',plugin_dir_url(__FILE__));
}

function vote_standalone_doc_table(){
global $wpdb;
$sql = "CREATE TABLE IF NOT EXISTS wp_vote_standalone_doc (
                                             ID INT UNSIGNED NOT NULL AUTO_INCREMENT  PRIMARY KEY,
                                             doc_id SMALLINT NOT NULL,
                                             votes SMALLINT NOT NULL,
                                             drilldown SMALLINT NOT NULL
                                             )";
require_once(ABSPATH . 'wp-admin/includes/upgrade.php');
dbDelta($sql);
}
register_activation_hook( __FILE__, 'vote_standalone_doc_table' );

class Vote_Standalone_Doc{

    function vote_load_js(){

            wp_enqueue_script('av-vote', DOC_VOTE_BASE_URL . 'js/av_vote.js', array( 'jquery' ));
            wp_localize_script('av-vote', 'av_vote_vars',
                               array(
                                     'ajaxurl' => admin_url( 'admin-ajax.php' ),
                                     'nonce' => wp_create_nonce('av-vote-nonce'),
                                     'thanks' => 'Thanks for your feedback.',
                                     'error_message' => 'Sorry, there was a problem processing your request.'
                                     )
                               );
            wp_register_style('vote_standalone_doc_survey', DOC_VOTE_BASE_URL . 'includes/style.css');
            wp_enqueue_style('vote_standalone_doc_survey', DOC_VOTE_BASE_URL . 'includes/style.css');
    }


    function __construct(){
    $this->hooks();
    }
    function hooks(){
        //add_action('wp_enqueue_scripts', 'vote_load_js');
        add_action('wp_head',array($this,'vote_load_js'));
        add_action( 'wp_ajax_register_vote', array($this,'handle_vote') );
    }

    function av_vsd_display_link(){
        global $wpdb;
        //Show Vote option only if Embeds_On_Page == 0
        global $post;

            $doc_id = $post->ID;

            $vote_count = $wpdb->get_results($wpdb->prepare("SELECT votes FROM wp_vote_standalone_doc WHERE doc_id = %d", $doc_id));
            if(is_array($vote_count)){$vote_count = intval($vote_count[0]->votes);}
          if(is_int($vote_count)){
                if($vote_count == 1){$vote_or_votes = 'Vote';}else{$vote_or_votes = 'Votes';} // Display "vote" or "votes"
                if(isset($doc_id)){
                    $html = '<div class="questions"><span id="question1"><a href="#" class="vote_for_doc" data-doc_id="'.$doc_id.'">
                    I would like to have this document integrated into CT2</a></span>

                    <span id="question2" class="drilldown_text">I would like the document to have in-line links to further information on various topics: <a href="#" class="drilldown" data-drilldown=1>Yes, show me drilldown content</a><a href="#" class="drilldown" data-drilldown=0>No thanks</a></span>

                    <span id="status">(<span class="vote-count">' . $vote_count . '</span> '.$vote_or_votes.' for ' . get_the_title($doc_id) . ')</span></div>';

                }else{ // get_the_title failed
                    $html = 'The title for this document was not found.';
                }

          }else{
              if(is_string($vote_count)){
                  $html = '$vote_count is a string in the database<p>' . print_r($vote_count);
              }if(is_array($vote_count)){
                    $html = '$vote_count is an array in the database<p>' . print_r($vote_count);
              }else{
                  $html = '$vote_count is not a string or an integer<p>' . var_dump($vote_count);
              }
          }
        //}
        return $html;
    }
    function handle_vote(){
        global $wpdb;

            /*if( !is_user_logged_in() )
            return false;*/

            if( !wp_verify_nonce( $_POST['nonce'], 'av-vote-nonce' ))
            die( 'Go away!');

            $get_old_votes = $wpdb->get_results($wpdb->prepare("SELECT votes FROM wp_vote_standalone_doc WHERE doc_id = %d", $_POST['doc_id']));
            if(is_array($get_old_votes)){$get_old_votes = $get_old_votes[0]->votes;}

            $old_drilldown = $wpdb->get_results($wpdb->prepare("SELECT drilldown FROM wp_vote_standalone_doc WHERE doc_id = %d", $_POST['doc_id']));
            if(is_array($get_old_votes)){$get_old_votes = $get_old_votes[0]->votes;}

            if($get_old_votes){
                $new_votes = $get_old_votes + 1;
                $new_drilldown = intval($_POST['drilldown']) + intval($old_drilldown);
                if(is_int($new_votes)){

                $update_vote = $wpdb->update( 'wp_vote_standalone_doc',
                                             array( 'votes' => $new_votes,
                                                   'drilldown' => $new_drilldown
                                                   ),
                                             array( 'doc_id' => $_POST['doc_id']
                                                     ),
                                             array( '%d', '%d' ),
                                             array( '%d' )
                                             );

                if(!$update_vote){
                    echo "Vote not recorded" . $wpdb->print_error();
                }else{
                    echo "Vote recorded";
                }
                }
                //$wpdb->print_error();
            }else{ // New row entry
                $insert_row = $wpdb->insert( 'wp_vote_standalone_doc',
                                            array( 'doc_id' => $_POST['doc_id'],
                                                    'drilldown' => $_POST['drilldown'],
                                                    'votes' => 1),
                                            array(  '%d','%d','%d' )
                                            );

                //$wpdb->print_error();
                if(!$insert_row){
                    echo "Vote not recorded";
                }else{
                    echo "Vote recorded";
                }
            }
        //}
        die();
    }

} // END CLASS MY_LIKE_BUTTON

$vote_button = new Vote_Standalone_Doc;
add_shortcode( 'vote', array('Vote_Standalone_Doc', 'av_vsd_display_link') );
?>