Fixes: #17360 - Ensure model is defined when rendering bulk_edit_button

[bctiemann]

Fixes: #17360

Addresses a common issue in HTMX navigation where the inclusion of a call to bulk_edit_button where the param model is a string raises an AttributeError: 'str' object has no attribute '_meta'.

This fix adds a check for truthiness of model before trying to render {% bulk_edit_button %} or {% bulk_delete_button %} in table.py.

[arthanson]

I'm not sure this is the correct fix (or might be a partial fix) as I think it might just be masking the underlying issue - if you do the scenario to go to the interface and then click the edit bulk edit button (without having any items selected) you are presented with an empty page instead of a toast as you are without HTMX navigation enabled and I think it might be because of this this change allowing a blank model.

I think (not sure) that we need to find why model isn't getting set and get it set correctly.

[bctiemann]

Yeah, agreed -- this didn't really sit right with me except as a one-liner noninvasive fix. I don't yet quite understand what the underlying issue is or whether model is even supposed to be present, but I'll set this to Draft and keep digging.

[bctiemann]

@arthanson I think the blank page on "no interfaces selected" condition is a separate issue entirely; it has to do with the fact that it's an HTMX request that encounters an error and then gets a redirect to the return_url, but because it's in an HTMX container it doesn't properly send the browser back to that URL at the top level. I think that needs to be addressed in a separate bugfix.

netbox/netbox/netbox/views/generic/bulk_views.py

Line 701 in 485d3ae

return redirect(self.get_return_url(request))

To deal with the immediate issue, I've reverted the change to the template and set model explicitly in the page context, after investigating more and finding that that variable is being set in a lot of other pages (particularly list views) but not in this ObjectChildrenView. It seems to behave correctly now without having to catch the conditional in the template because model is not used except in the {% if request.htmx %} block.

[bctiemann]

Note that the surface-level error (model being interpreted as a str) was because the construct {% bulk_edit_button model query_params=request.GET %} passes in an unset or missing model context variable as an empty string, because it's interpolated as nothing. It's not that model is actually a str, it's that it isn't present in the context at all and the template processor just swallows that condition by treating the missing param as a space in the tag.

[jeremystretch]

The template htmx/table.html is used in several places; this needs to be addressed in all of them. It's probably sufficient to tweak the template to pass object to the bulk action button tags, rather than model.

[bctiemann]

All the other occurrences of bulk_action_button are in list views though. Wouldn't those have an object_list rather than an object?

[bctiemann]

Passing self.child_model (e.g. Interface) to the template instead of model (e.g. Device) seems like the right answer here. The success URL now pushes to the Interfaces tab as is correct.