QUploader supporting other services

[Mike Key]

I need to process files locally and QUploader looks like the best match except it requires url and supports only http protocol by now.
Suppose file processing is just calculating files hashes. Large files can take long to process so I need to override progress as well.
I can’t quite get how to extend the component to override. There’s an example API in the docs extending QUploaderBase.js, but I can’t get the whole picture what to do with it next.

https://quasar.dev/vue-components/uploader#Supporting-other-services

You’ll be creating a new Vue component that extends the Base of QUploader that you can then import and use in your website/app.

I’d appreciate a more extended explanation on how to extend QUploader on some simple example like returning files sizes or hashes array.