How to set properties for post while posting news feed using graph api

I am trying to set properties of post. And I am posting news feed using curl.

I am setting properties like this but it is not working.

$message = 'Message 1';
$caption = 'Caption 1';
$media["properties"] = array('category' => array( 'text' => 'humor', 'href' => 'http://www.icanhascheezburger.com/category/humor'));
$media["media"] = array("type" => "image", "src"=> $imageUrl , "href"=>$link);
$attachment = array ('name' => $caption,
             'link' => $appUrl ,
             'caption' => 'Test Caption',
             'description' => $message,
             'attachment' =>  $media
            );

Feed is getting published, but properties are not coming.

Please suggest me to how I should set the properties.