class BP_Blog_Post_Fav {

	var $activity_id;

	function init() {
		add_action( 'the_post', array( &$this, 'get_blog_post_activity_id' ) );
	}

	function get_blog_post_activity_id() {
		global $current_blog, $post;

		if( isset($post->ID) ) :
			$activity_id = bp_activity_get_activity_id( array(
			'user_id' => $post->post_author,
			'type' => 'new_blog_post',
			'component' => 'blogs',
			'item_id' => $current_blog->blog_id,
			'secondary_item_id' => $post->ID) );

			$this->activity_id = $activity_id;

			if( !empty($this->activity_id) ) {
				add_filter( 'bp_get_activity_favorite_link', array( &$this, 'bp_get_activity_favorite_link' ) );
				add_filter( 'bp_get_activity_unfavorite_link', array( &$this, 'bp_get_activity_unfavorite_link' ) );
				add_filter( 'bp_get_activity_is_favorite', array( &$this, 'bp_get_activity_is_favorite' ) );
			}

		endif;

	}

	function bp_get_activity_favorite_link() {
		global $current_blog;

		if( $current_blog->blog_id != BP_ROOT_BLOG )
			switch_to_blog( BP_ROOT_BLOG );

		$nonce = wp_nonce_url( site_url( BP_ACTIVITY_SLUG . '/favorite/' . $this->activity_id . '/' ), 'mark_favorite' );

		if( $current_blog->blog_id != BP_ROOT_BLOG )
			restore_current_blog();

		return $nonce;
	}

	function bp_get_activity_unfavorite_link() {
		global $current_blog;

		if( $current_blog->blog_id != BP_ROOT_BLOG )
			switch_to_blog( BP_ROOT_BLOG );

		$nonce = wp_nonce_url( site_url( BP_ACTIVITY_SLUG . '/unfavorite/' . $this->activity_id . '/' ), 'unmark_favorite' );

		if( $current_blog->blog_id != BP_ROOT_BLOG )
			restore_current_blog();

		return $nonce;
	}

	function bp_get_activity_is_favorite() {
		global $bp;

 		return in_array( $this->activity_id, (array)bp_activity_get_user_favorites($bp->loggedin_user->id) );
	}
}
$my_bp_favorite = new BP_Blog_Post_Fav();
$my_bp_favorite->init();