Better ArrayField/list formatting in the admin

[Dan Watson]

When specifying an ArrayField in list_display or readonly_fields, the admin shows a rather ugly python representation of the list, e.g.:

[u'Value 1', u'Value 2', u'Value 3']

A simple solution would be to check for isinstance(value, (list, tuple)) in django.contrib.admin.utils.display_for_value and return a comma- or semicolon-separated display string, then change django.contrib.admin.utils.display_for_field to call display_for_value at the end instead of just smart_text. This would be pretty un-intrusive, and work for any fields providing list type values.

A more thorough solution might involve some mechanism by which fields or ModelAdmin instances can customize the display formatting of field values. Or maybe even some sort of template-based rendering solution in line with ​https://github.com/django/django/pull/6498.

[Dan Watson]

​https://github.com/django/django/pull/6558

[Dan Watson]

Added tests to the PR.

[Tim Graham <timograham@…>]

In ad403ffa:

Fixed #26582 -- Added prettier admin display for list values.