admin_v3.py

import tempfile
from itertools import chain

from django.contrib import admin
from django.contrib.admin.utils import NestedObjects
from django.core import serializers
from django.http import HttpResponse

from example_app.models import *


@admin.action(description="Export Model")
def export_model(modeladmin, request, queryset):
    model_file = tempfile.TemporaryFile()
    with model_file as tmp_file:
        serialized_objects = serializers.serialize(
            "json", queryset
        )
        tmp_file.write(serialized_objects.encode("utf-8"))
        tmp_file.seek(0)
        response = HttpResponse(tmp_file.read(), content_type="application/json")
        response["Content-Disposition"] = "attachment; filename=model.json"
        return response


# New
@admin.action(description="Export Model with related objects")
def export_model_with_related_objects(modeladmin, request, queryset):
    data_model_file = tempfile.TemporaryFile()
    with data_model_file as tmp_file:
        collector = NestedObjects(using="default")
        collector.collect(queryset)
        objects = list(chain.from_iterable(collector.data.values()))
        serialized_objects = serializers.serialize(
            "json", objects, use_natural_foreign_keys=True, use_natural_primary_keys=True
        )
        tmp_file.write(serialized_objects.encode("utf-8"))
        tmp_file.seek(0)
        response = HttpResponse(tmp_file.read(), content_type="application/json")
        response["Content-Disposition"] = "attachment; filename=model_with_related_objects.json"
        return response


class PersonAdmin(admin.ModelAdmin):
    # New
    actions = [export_model, export_model_with_related_objects]


admin.site.register(Person, PersonAdmin)
admin.site.register(Book)