In wordpress, a better way to check if an author has a gravatar or not. Sometimes you might want to check to see if a gravatar exists and not display any image if there isn't one. Uses the wordpress HTTP and caching apis. A better version of this: http://codex.wordpress.org/Using_Gravatars#Checking_for_the_Existence_of_a_Gravatar
/**
* Utility function to check if a gravatar exists for a given email or id
* @param int|string|object $id_or_email A user ID, email address, or comment object
* @return bool if the gravatar exists or not
*/
function validate_gravatar($id_or_email) {
//id or email code borrowed from wp-includes/pluggable.php
$email = '';
if ( is_numeric($id_or_email) ) {
$id = (int) $id_or_email;
$user = get_userdata($id);
if ( $user )
$email = $user->user_email;
} elseif ( is_object($id_or_email) ) {
// No avatar for pingbacks or trackbacks
$allowed_comment_types = apply_filters( 'get_avatar_comment_types', array( 'comment' ) );
if ( ! empty( $id_or_email->comment_type ) && ! in_array( $id_or_email->comment_type, (array) $allowed_comment_types ) )
return false;
if ( !empty($id_or_email->user_id) ) {
$id = (int) $id_or_email->user_id;
$user = get_userdata($id);
if ( $user)
$email = $user->user_email;
} elseif ( !empty($id_or_email->comment_author_email) ) {
$email = $id_or_email->comment_author_email;
}
} else {
$email = $id_or_email;
}
$hashkey = md5(strtolower(trim($email)));
$uri = 'http://www.gravatar.com/avatar/' . $hashkey . '?d=404';
$data = wp_cache_get($hashkey);
if (false === $data) {
$response = wp_remote_head($uri);
if( is_wp_error($response) ) {
$data = 'not200';
} else {
$data = $response['response']['code'];
}
wp_cache_set($hashkey, $data, $group = '', $expire = 60*5);
}
if ($data == '200'){
return true;
} else {
return false;
}
}