Initially empty Signature has no value -> signatureObject.value() returns undefined. When the control is focused it gets a default value representing the blank background of the signature pad.
Validating the Signature based on its value gets quite complex as it requires considering this default base64string.
It would be great if the control would provide functionality to validate for mandatory user input
If one wants to read the resulting signature server-side (after a button-click / form submission), one kind of has to work with a lot of javascript and hidden input fields to transfer the base64-encoded png towards the server. It would be way nicer if you could provide the content of the signature as a server-side property of the RadSignature-control (during post-back).
Would it be possible to include an additional button with a feature that allows a user to Type their signature (e.g., like in MS Paint, you can still type and it saves as an image).