Add a way to disable column sorting in the admin

[Ramiro Morales]

Consider this model:

# models.py
from __future__ import unicode_literals

from django.db import models


class CreditCard(models.Model):
    issued_to = models.CharField(max_length=40)
    good_thru = models.DateField()
    last_four_digits = models.CharField(max_length=4)

And this admin.py for the app:

from django.contrib import admin

from app.models import CreditCard


class CCAdmin(admin.ModelAdmin):
    list_display = [
        'issued_to',
        'good_thru',
        'last_four_digits',
    ]
    ordering = ['good_thru']


admin.site.register(CreditCard, CCAdmin)

The user has specified explicitly he/she wants the change list view grid to be sortable by default by the credt card expiration date by using the ModelAdmin.orderingoption.

Now, the interactive sorting changelist functionality that allows one to sort by a column by clicking on its header automagically allows one to also sort by other columns chosen by a documented logic (i.e. not if callable columns, etc.).

In the example, it allows users to also sort by the name of the credit card owner which, even if not asked for, seems useful.

Where it doesn't make so much sense is, for the example, in the case of the 'last four digits' column.

IMHO there should be a way to express which columns one wants this functionality for without having to resort to things like:

class CCAdmin(admin.ModelAdmin):
    list_display = [
        'issued_to',
        'good_thru',
        'last4digits',
    ]
    #...

    def last4digits(self, obj):
        """So we don't get bogus ordering by this field in the change list view."""
        return obj.last_four_digits
    last4digits.short_description = '4 last digits'

[Ramiro Morales]

There is some work in this branch: ​https://github.com/django/django/compare/master...ramiro:ticket_25790?expand=1

I'm thinking now it's wrong or at least incomplete.

I suspect this is overloading the ModelAdmin.ordering option (which is for specifying the change list default/initial ordering) with an additional function.

A possible solution, provided the feature proposed by this ticket is accepted, is to have another option e.g. orderable_by which when not provided makes things behave like they do now and when specified (a list of fields) is intersected with ordering to get the final list of columns which will actually be allowed to sort by.

[Tim Graham]

I guess we should add the the get_orderable_by(request) version too.

[Sasha Gaevsky]

​PR

[Philip James]

The PR looks good to me: the patch submitter has answered all questions, added tests, and all checks pass.

[Simon Charette]

The documentation requires adjustments as the feature didn't make it in 1.10.