Code PHP pour faire un cache de Gravatar. Utilité ? Éviter que Gravatar puisse tracer les internautes, que le site soit bousillé si Gravatar est injoignable, … Les commentaires sont en anglais.

get.php

<?php 
/*
How to use it:
call it from your website like this:
http://www.yoursite.com/some_folder_for_gravatar_caching/get.php?g={md5_from_email}
*/
$expire = time() -604800 ;  // default: 604800 (7 days)
if (isset($_GET['g']))  // g given ? if yes...
{
if (strlen($_GET['g']) !== 32) { die; }  // g is 32 character long ? if no, die.
$hash = ereg_replace("[^a-f0-9]", "", $_GET['g'] );  // strip out anything that doesn't belong in a md5 hash
if (strlen($hash) != 32) { die; }  // still 32 characters ? if no, given hash wasn't genuine. die.
$newfile = $hash.'.png';
$file = 'https://secure.gravatar.com/avatar/'.$hash.'?s=60&d=monsterid';  // gravatar, 60px monsterid.
if(file_exists($newfile) && filemtime($newfile) < $expire)
{ unlink($newfile); }  // expired gravatar, out !
if (file_exists($newfile))
{ }  // the gravatar wasn't removed before: it's valid and doesn't need refreshment
else
{ copy($file, $newfile);   // gravatar deleted, getting new.
$imagecheck = getimagesize($newfile);
if ($imagecheck['mime']!=='image/png')  // is it a PNG ?
  {   
imagepng(imagecreatefromjpeg($newfile),$newfile.'2');  // if no, creating PNG and replacing
unlink($newfile);
rename($newfile.'2', $newfile);
  }
}
header('Location: '.$newfile.''); }   // and finally let's redirect to the cached gravatar.
else
{ header("HTTP/1.0 404 Not Found"); echo "erreur"; }  // g not given, return error.
?>

Pour passer les avatars Wordpress, envoyez ce fichier dans le dossier des extensions et activez-le:

gravatar.php

<?php
add_filter('get_avatar', 'be_gravatar_filter', 10, 5);
function be_gravatar_filter($avatar, $id_or_email, $size, $default, $alt) {
$email = 'a@b.c';
if ( is_numeric($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;
	}
 
	if ( empty($default) ) {
		$avatar_default = get_option('avatar_default');
		if ( empty($avatar_default) )
			$default = 'mystery';
		else
			$default = $avatar_default;
	}
 
 
 
 
	if ( !empty($email) )
		$email_hash = md5( strtolower( $email ) );
$return = '<a href="https://secure.gravatar.com/avatar/'.$email_hash.'?d=monsterid&amp;r=G&amp;s=500"><img class="gravatar" src="http://www.votre.site/wp-content/gravatars/get.php?g='.$email_hash.'" alt="'.$alt.'"></a>';
return $return;
}
?>