Developing a Facebook Application for absolute beginners – step 5

<?php
 
require_once 'facebook.php';
 
$appapikey = 'xxxxx';
$appsecret = 'xxxxx';
 
$facebook = new Facebook($appapikey, $appsecret);
 
$user_id = $facebook->require_login();
 
$friends = $facebook->api_client->friends_get();
 
echo "<p>Hello <fb:name uid=\"$user_id\" useyou=\"false\" linked=\"false\" firstnameonly=\"true\"></fb:name>, you have ".count($friends)." friends";
 
foreach($friends as $friend){
     $infos.=$friend.",";
}
 
$infos = substr($infos,0,strlen($infos)-1);
 
$gender=$facebook->api_client->users_getInfo($infos,'sex');
 
$gender_array = array(); 
 
foreach($gender as $gendervalue){
     $gender_array[$gendervalue[sex]]++;
}
 
$male = round($gender_array[male]*100/($gender_array[male]+$gender_array[female]),2);
$female = 100-$male;
 
echo "<ul><li>Males: $male%</li><li>Females: $female%</li></ul>";
 
$message = "has ".count($friends)." friends. $male% of them are male. $female% are female";
 
$image = array();
$image[type]="image";
$image[src]="http://www.gamemummy.com/facebook/genderz_demo/genderz.png";
$image[href]="http://apps.facebook.com/genderz_demo/";
 
$attachment = array();
$attachment[name] =  "Try the application!!";
$attachment[href] = "http://apps.facebook.com/genderz_demo/";
$attachment[caption] = "{*actor*} has ".count($friends)." friends";
$attachment[description] = "powered by genderz_demo";
$attachment[media] = array($image);
 
$has_permission = $facebook->api_client->users_hasAppPermission("publish_stream");
 
if(!$has_permission){
     echo "<br /><fb:prompt-permission perms=\"publish_stream\">Publish results on your wall!!</fb:prompt-permission>";
}
else{
     $facebook->api_client->stream_publish($message,$attachment);
}
 
if(isset($_POST[ids])){
     $message = "is inviting you to use <a href = \"http://apps.facebook.com/genderz_demo/\">genderz_demo</a>!! Try it!";
     $ids_list = implode(",",$_POST[ids]);
     $facebook->api_client->notifications_send($ids_list,$message,'user_to_user');
     echo "<br /><br />Thank you for inviting ".count($_POST[ids])." friends to genderz_demo";
}
else {
 
?>
 
<fb:request-form
     action="http://apps.facebook.com/genderz_demo/"
     method="POST" 
     type="genderz_demo" 
     content="Hello. Please use my app. <?php echo htmlentities("<fb:req-choice url=\"http://apps.facebook.com/genderz_demo/\" label=\"Try it!!\"") ?>" >
     <fb:multi-friend-selector showborder="false" actiontext="Send some spam invites to Genderz Demo!"> 
</fb:request-form>
 
<?php } ?>