Allow specifying a custom base URL when registering ModelAdmin

Is your proposal related to a problem?

Prompted by https://stackoverflow.com/q/71248504/1853523, where a user set up ModelAdmin for a model in an app named ‘users’, which resulted in it registering URLs under /admin/users/ that clashed with Wagtail’s own URLs from wagtail.users. It seems that there’s currently no straightforward way to customise the URL path that ModelAdmin registers - you need to override AdminURLHelper instead.

Describe the solution you’d like

ModelAdmin could support a base_url_path option, e.g.

class BookAdmin(ModelAdmin):
    model = Book
    base_url_path = 'library'  # make URLs appear under `/admin/library/` instead of `/admin/myapp/books/`

This could be implemented as follows:

• Extend wagtail.contrib.modeladmin.helpers.url.AdminURLHelper.__init__ to accept an optional base_url_path keyword argument
• In _get_action_url_pattern, use this to build the URL string, falling back on {app_label}/{model_name} if not specified
• Update wagtail.contrib.modeladmin.options.ModelAdmin to add base_url_path to the list of config attributes, and pass this on when initialising self.url_helper. Note that we need to deal with the possibility that a user might have created a subclass of AdminURLHelper in their own code and overridden __init__, as in this case their code won’t know about the new argument - I’d suggest using accepts_kwarg to check this before calling it, and outputting a deprecation warning if it doesn’t. We can then remove that extra check in a future release.
• Add tests and documentation

[vupham04]

Hi, because @Nawarrr hasn’t commented in 2 weeks, so I have worked on this issue and come up with a solution.

1. About the tests, I’m thinking about editing a Model in wagtail\test\modeladmintest\wagtail_hooks.py to include base_url_path, and then in wagtail\contrib\modeladmin\tests\test_modeladmin_edit_handlers.py, in response = self.client.get(…) for the appropriate model, I will edit the URL there to fit base_url_path. Is it okay?

2. For documentation, in ModelAdmin, should we create a sub-page for customizing base URL, or can I just add it to the Additional tips and tricks?

Should I still create a pull request without tests and documentations, and amend it later?

[lb-]

Go for it @vupham04 thanks for communicating.