returns the current fb_sig_params (only if they validated properly)
returns the current user‘s Facebook session (an instance of FacebookWebSession)
Aliases to path_to_image for Rails 1.0 backwards compatibility
returns true if the render is using mock ajax
returns true if the user is viewing the canvas
returns true if the user is in an iframe
overrides the path_to_image method to ensure that all images are written with absolute paths
[Validate]