Getting rest history from Django simple History - django-rest-framework

Question

I am using django-simple-history (1.8.1) and DRF (3.5.3). I want to get a rest service containing the history of each element. Let's take an example !
models.py
class Product(models.Model):
name = models.CharField(max_length=50)
price = models.IntegerField()
history = HistoricalRecords()
def __str__(self):
return self.name
So, what must be serializers.py ? I'd like to GET something like :
[
{
"id": 1,
"name": "Apple",
"price": 8,
"history": [
{
"history_id": 1,
"id": 1,
"name": "Apple",
"price": 0,
"history_date": "2016-11-22T08:02:08.739134Z",
"history_type": "+",
"history_user": 1
},
{
"history_id": 2,
"id": 1,
"name": "Apple",
"price": 10,
"history_date": "2016-11-22T08:03:50.845634Z",
"history_type": "~",
"history_user": 1
},
{
"history_id": 3,
"id": 1,
"name": "Apple",
"price": 8,
"history_date": "2016-11-22T08:03:58.243843Z",
"history_type": "~",
"history_user": 1
}
]
}
]
After searching whitout finding the solution, I finally found it by myself. But if someone have a better solution...

Answer 1

I know it's been a year, but anyway, maybe someone finds it useful. Here is my solution (it seems far easier to me):
A new serializer field:
class HistoricalRecordField(serializers.ListField):
child = serializers.DictField()
def to_representation(self, data):
return super().to_representation(data.values())
Now simply use it as a a field in your serializer:
history = HistoricalRecordField(read_only=True)
This makes use of DRF's built in list and dict serializers, only trick is to pass it the correct iterable, which is being done by calling .values() on the simple-history model manager class.

Answer 2

Here's my solution.
In serializers.py :
from rest_framework import serializers
from .models import Product
class sHistory(serializers.ModelSerializer):
def __init__(self, model, *args, fields='__all__', **kwargs):
self.Meta.model = model
self.Meta.fields = fields
super().__init__()
class Meta:
pass
class sProduct(serializers.ModelSerializer):
class Meta:
model = Product
fields = '__all__'
history = serializers.SerializerMethodField()
def get_history(self, obj):
model = obj.history.__dict__['model']
fields = ['history_id', ]
serializer = sHistory(model, obj.history.all().order_by('history_date'), fields=fields, many=True)
serializer.is_valid()
return serializer.data
It works ! I'm quite proud about it ! any suggestions ?

Answer 3

There seems to be an even clearer and simpler way
class AnySerializer(serializers.ModelSerializer):
history = serializers.SerializerMethodField()
class Meta:
model = MyModel
fields = (....
....
'history',
)
read_only_fields = ('history',)
def get_history(self, obj):
# using slicing to exclude current field values
h = obj.history.all().values('field_name')[1:]
return h

Answer 4

You can create a serializer like this:
class ProductHistorySerializer(serializers.ModelSerializer):
class Meta:
model = Product.history.model
fields = '__all__'
Then in view, You can have the code below:
#...
logs = ProductHistorySerializer(Product.history.filter(price__gt=100), many=True)
return Response({'isSuccess': True, 'data': logs.data})