BaseModelAdmin.formfield_for_dbfield() in desperate need of refactor

[James Bennett]

See attached patch, which moves all of the model-field-specific overrides out into a dictionary. This has the side effect of increasing customizability :)

[Malcolm Tredinnick]

I'd like to hear if brosner has any particular qualms about this, but it looks like a win to me. That function is a little scary and small children might accidentally look at it.

(Brian: wontfix if you have some really good reason why this is a bad idea.)

[Daniel Pope <dan@…>]

This fixes #8326 but breaks admin widgets for subclasses of model fields.

I suggest the dictionary keys are not model.Fields but forms.Widgets. It is the widgets that we are replacing, so as long as the admin widgets are drop-in replacements, we can just call .formfield() and check for replacement widgets for the widget class in the forms.Field returned.

[Jacob]

This is an obvious win, but I see no reason to let the code churn around at this point in the 1.0 process. Let's do this later.

[Jacob]

I've attached a more complete patch with tests/docs; it's also ​on my github. Since James' version, I've done a couple things:

• Broke what was left of formfield_for_dbfield into a handful of smaller methods to make those easier to screw around with.
• Separated the defaults and the overrides so that it's easier for subclasses to override the defaults without accidentally emptying out the dictionary (as I did while testing).
• Made sure that the ordering is correct (**kwargs overrides formfield_overrides which overrides the defaults) to fix #9148 while we at it.

[Jacob]

(In [9760]) Cleaned up and refactored ModelAdmin.formfield_for_dbfield:

• The new method uses an admin configuration option (formfield_overrides); this makes custom admin widgets especially easy.
• Refactored what was left of formfield_for_dbfield into a handful of smaller methods so that it's easier to hook in and return custom fields where needed.
• These formfield_for_* methods now pass around request so that you can easily modify fields based on request (as in #3987).

Fixes #8306, #3987, #9148.

Thanks to James Bennet for the original patch; Alex Gaynor and Brian Rosner also contributed.

[(none)]

Milestone post-1.0 deleted