AJAX-Action-Hook-Plugin-Functions.php

AJAX-Action-Hook-Plugin-Functions.php

<?php // used here only for enabling syntax highlighting. Leave this out if it's already included in your plugin file.

// define the actions for the two hooks created, first for logged in users and the next for logged out users
add_action("wp_ajax_my_user_like", "my_user_like");
add_action("wp_ajax_nopriv_my_user_like", "please_login");

// define the function to be fired for logged in users
function my_user_like() {
   
   // nonce check for an extra layer of security, the function will exit if it fails
   if ( !wp_verify_nonce( $_REQUEST['nonce'], "my_user_like_nonce")) {
      exit("Woof Woof Woof");
   }   
   
   // fetch like_count for a post, set it to 0 if it's empty, increment by 1 when a click is registered 
   $like_count = get_post_meta($_REQUEST["post_id"], "likes", true);
   $like_count = ($like_count == ’) ? 0 : $like_count;
   $new_like_count = $like_count + 1;
   
   // Update the value of 'likes' meta key for the specified post, creates new meta data for the post if none exists
   $like = update_post_meta($_REQUEST["post_id"], "likes", $new_like_count);
   
   // If above action fails, result type is set to 'error' and like_count set to old value, if success, updated to new_like_count  
   if($like === false) {
      $result['type'] = "error";
      $result['like_count'] = $like_count;
   }
   else {
      $result['type'] = "success";
      $result['like_count'] = $new_like_count;
   }
   
   // Check if action was fired via Ajax call. If yes, JS code will be triggered, else the user is redirected to the post page
   if(!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest') {
      $result = json_encode($result);
      echo $result;
   }
   else {
      header("Location: ".$_SERVER["HTTP_REFERER"]);
   }

   // don't forget to end your scripts with a die() function - very important
   die();
}

// define the function to be fired for logged out users
function please_login() {
   echo "You must log in to like";
   die();
}