Error: TypeError unhashable type: 'list'

[mathias4github]

Getting the same issue, the workaround is not working for me. My model ist not using any ReadOnly Fields.

destination = CountryField(default='DE', multiple=True)

Request Method: | GET
-- | --
/admin/products/shippingproduct/
3.0.8
TypeError
unhashable type: 'list'
/mpc/env/lib/python3.7/site-packages/django/contrib/admin/utils.py in display_for_field, line 382

Sees to be a problem here:

`

Variable	Value
_boolean_icon	<function _boolean_icon at 0x7ff8cb481510>
empty_value_display	'-'
field	<django_countries.fields.CountryField: destination>
value	[Country(code='DE')]

`

Originally posted by @mathias4github in #298 (comment)

[jedie]

I ran into the same problem and can't use the work-a-round from #298 (comment)

[browniebroke]

I have the same problem as well. I haven't tested it yet, but in case you're using PostgreSQL, an alternative option to using CountryField(multiple=True) might be to use an ArrayField.

The example in the readme would look like this (I think):

from django.contrib.postgres.fields import ArrayField
from django.db import models
from django_countries import countries
from django_countries.fields import CountryField


class Incident(models.Model):
    title = models.CharField(max_length=100)
    countries = ArrayField(
        base_field=CountryField(),
        size=len(countries),
    )

I guess this would work better out of the box with Django. Anyone tried this approach before?

[jedie]

I ran into the same problem and can't use the work-a-round from #298 (comment)

I made a work-a-round for Admin inlines. Looks like:

class DjangoCountriesInlineReadOnlyUserFixMixin:
    def countries_readonly(self, obj):
        return ', '.join(country.name for country in obj.countries)
    countries_readonly.short_description = _('Countries')

    def has_parent_change_permission(self, request):
        parent_model = self.parent_model
        opts = parent_model._meta
        codename = get_permission_codename('change', opts)
        return request.user.has_perm(f'{opts.app_label}.{codename}')

    def get_fields(self, request, obj=None):
        fields = super().get_fields(request, obj)

        can_change = (
            self.has_change_permission(request) and self.has_parent_change_permission(request)
        )
        if not can_change:
            fields.remove('countries')
            self.readonly_fields = list(self.readonly_fields) + ['countries_readonly']

        return fields

class FooBarInline(DjangoCountriesInlineReadOnlyUserFixMixin, admin.TabularInline):
    model = FooBarModel # this model has the 'countries' field
    #...

The idea is to replace the model field (in this example: counties) from the form.

[philgyford]

I have a similar problem but can't yet figure out a solution. For my ModelAdmin I want to add countries to readonly_fields – it's never user-editable on this model – but I'm stumped. I've tried adapting the above but the get_fields() method never seems to be called when rendering my change page, from what I can tell.

[philgyford]

While doing something else I figured out the solution.

models.py:

class MyModel(models.Model):
    countries = CountryField(multiple=True, blank=True)

admin.py:

from django.contrib import admin
from django.utils.html import format_html_join
from .models import MyModel

@admin.register(MyModel)
class MyModelAdmin(admin.ModelAdmin):
    fields = ("get_countries",)
    readonly_fields = ("get_countries",)

    @admin.display(description="Countries")
    def get_countries(self, obj):
        return format_html_join(
            ", ",
            "{}",
            ((country.name,) for country in obj.countries),
        )

That example doesn't really need format_html_join() but you could instead show the flags:

    @admin.display(description="Countries")
    def get_countries(self, obj):
        return format_html_join(
            " ",
            "<span title='{}'>{}</span>",
            ((country.name, country.unicode_flag) for country in obj.countries),
        )

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