Django MultipleChoiceField JSONField

admin.py

from django.contrib import admin
from django.template.loader import render_to_string

from .forms import UserRoleAdminForm
from .models import UserRole


@admin.register(UserRole)
class UserRoleAdmin(admin.ModelAdmin):
    list_display = ('name', 'fields_data',)
    form = UserRoleAdminForm

    def fields_data(self, obj):
        return render_to_string('fields_data.html', {
            'fields': obj.fields_dict.items()
        })

fields_data.html

{% load staticfiles %}
<ul>
  {% for field, selected in fields %}
  <li>
    {% if selected %}
    <img src="{% static 'admin/img/icon-yes.svg' %}" alt="True">
    {% else %}
    <img src="{% static 'admin/img/icon-no.svg' %}" alt="False">
    {% endif %}
    {{ field }}
  </li>
  {% endfor %}
</ul>

forms.py

from django import forms

from .models import UserRole


class UserRoleAdminForm(forms.ModelForm):
    fields = forms.MultipleChoiceField(choices=UserRole.CHOICES, widget=forms.CheckboxSelectMultiple)

    class Meta:
        model = UserRole
        fields = ('name', 'fields',)

models.py

from collections import OrderedDict

from django.contrib.postgres.fields import JSONField
from django.db import models


class UserRole(models.Model):
    CHOICES = (
        ('admin:invite', 'Invite user'),
    )

    name = models.CharField(max_length=255, unique=True)
    fields = JSONField(default=list)

    @property
    def fields_dict(self):
        fields = set(self.fields)
        return OrderedDict([
            (field[0], field[0] in fields)
            for field in self.CHOICES
        ])

Thank you very much.