Admin form UI improvements and multi file upload support

[paigewilliams]

Adds the following features to the package

Admin form UI changes:

• Shows a progress bar while upload is in progress
• Shows a cancel all button while uploads are in progress to stop all uploads
• Shows a pause/resume all button while uploads in progress to pause/resume all uploads
• Adds a remove button for each file in an upload
• Hides the input after a file is uploaded. User must delete all files to re show the input

Supports Multi-file uploads

• adds a field called FormResumableMultipleFileField that handles sending multiple files in a list
• Consumers of the package can manage this by in the save_model method, doing the following:

def save_model(): 
 uploaded_file_paths = form.cleaned_data.get("files") # whatever is the name of the field using FormResumableMultipleFileField

 if uploaded_file_paths and isinstance(uploaded_file_paths, list):
   for uploaded_file_path in uploaded_file_paths:
     ... 

Config changes

• Adds a max_files param for AsyncFileField to allow for configuration of how many files can be uploaded to a file input. Defaults to undefined, which is unlimited.

Storages changes

• adds path for upgrading to Django 5+ which deprecates the DEFAULT_FILE_STORAGE in favor of storages while maintaining backwards compatibility

Testing

• Adds selenium tests for pause, resume, cancel behavior
• Adds testing for storage change

Screenshots

[paigewilliams]

I tried to get selenium tests to work and didnt seem like worth the effort. If time allows, it might be worth looking into using something like playwright instead considering they have better docs on how to run in a GH action https://playwright.dev/python/docs/ci-intro

[paigewilliams]

copilot was EXTREMELY helpful in migrating to playwright! wooooo

[paigewilliams]

Changes in this file are in the effort of resolving the following error, while maintaining support for older versions of django

RemovedInDjango51Warning: django.core.files.storage.get_storage_class is deprecated in favor of using django.core.files.storage.storages

[paigewilliams]

markdown > rst

[pollardld]

Okay to ship without resolving this:

If an there is an error during json.loads() on line 50, then file_path will raise an error here bc it hasn't been defined.

A potential fix is to declare file_path before try statement file_path = None.

[paigewilliams]

good catch! I made the change per your suggestion.

[pollardld]

This is quality open source software!