FileUpload: Validate files before adding on drop

[wolnynick]

[ ] bug report
[X] feature request
[ ] support request => Please do not submit support request here, instead see https://forum.primefaces.org/viewforum.php?f=57

Current behavior
There is no validation which types goes into file uploader

Expected behavior
Please add validation to FileUploader based on accept property. Or tell me how can I validate by myself and then remove items. I tried to remove wrong files on 'onSelect' event, but it's not working with

fileUploadRef.current.state.files = []
fileUploadRef.current.files = []
e.files = {}
e.originalEvent.dataTransfer.files[0] = {}

Minimal reproduction of the problem with instructions
FileUpload -> multiple: true -> mode: advanced

• PrimeReact version:
  7.2.1

[melloware]

Can you give me the example accept value you are using?

[wolnynick]

accept="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"

And I should mention it earlier, that I'm talking about drag and drop

[melloware]

I think we need to add an onBeforeDrop method so you can hook in and return false; if you don't want the drop to proceed.

[melloware]

Especially from the HTML5 docs for accept:

https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/file#accept

For instance, there are a number of ways Microsoft Word files can be identified, so a site that accepts Word files might use an like this:

<input type="file" id="docpicker"
  accept=".doc,.docx,application/msword,application/vnd.openxmlformats-officedocument.wordprocessingml.document">