The internal implementation of the Upload widget allows you to identify which is the file object, that is being uploaded to the remote endpoint.
Regardless of the mode of operation, a unique identifier (
uid) is generated for each file. In the case of a synchronous or asynchronous upload with the batch option enabled, the single
uid that is generated, stands for the whole batch of files, selected at the same time. In the case of asynchronous upload with the batch option disabled, a
uid is generated for each separate file.
uid is added to all the below events as a property of the