If you provide a one-argument block to the TLLoginComponent>>#onRegistration: method, your block will be evaluated with pending new user objects before the registration email confirmation (if any) is sent. Your block should answer true to allow the registration to proceed, or false to cancel the registration without further interaction with the user. If you return false, you should arrange to inform the user as to why their registration attempt is being rejected.
In your onRegistration block, you can populate the new user's applicationProperties dictionary with initial values. This can be useful if, for example, you have allowed an unregistered user to work at your website and for them to save their work you require them to register for an account. Since the registration confirmation will take place in another session the question arises as to where to save their work during the registration confirmation process (and how to dispose of it if the registration is not confirmed.) Saving the user's work in the pending user object's applicationProperties dictionary provides the answer. When the new user logs in the first time, anything placed in their applicationProperties dictionary in the onRegister block will be present in their TLSession user object.
Here is an example onRegistration block in which userObjects are saved in the pending user's applicationProperties:
loginComponent onRegistration: [ :pendingUser |
put: self userObjects.