Web tutorial: handling a WILL file
Due to the specifics of the web architecture there is no support for the WILL file contents.
The only way to get the information from the file is to extract its contents.
While the Web SDK does not have support for the WILL file format, it provides InkEncoder and InkDecoder classes that can access the protobuf data from the file.
For more information about the structure of the file see WILL File Format
Also we highly recommend you to check 2.2 (Stroke serialization) from the examples which can be found in the downloaded SDK.