How to post array data through serializers? - django

Question

I want to post some array data through serializer's create method. How do I get array data in serializer's create method?
this is my result which gives error because of array's data. I have to post belows particular,inch_first...rate arrays data.
{
"order_media": {
"client_employee": "4",
"client": "63",
"narration": "Print ad",
"vendor": "68",
"total_amount": "2590.00",
"discount_rate_client": "10.00",
"discount_amount_client": "259.00",
"service_percentage": "10.00",
"service_amount": "259.00",
"client_vat": "388.50",
"total_receivable": "2978.50",
},
"pub_date": "2019-04-03",
"particular": ["Banner", "Poster", "Plastic banner"],
"inch_first": ["4", "5", "3"],
"inch_second": ["4", "5", "3"],
"size": ["16.00", "25.00", "9.00"],
"quantity": ["5", "5", "6"],
"rate": ["10", "10", "10"],
}
This is my model
class RequestPrintProduction(models.Model):
particular = models.CharField(max_length=255,null=True,blank=True)
inch_first = models.CharField(max_length=45,null=True,blank=True)
inch_second = models.CharField(max_length=45,null=True,blank=True)
size = models.CharField(max_length=45,blank=True, null=True)
quantity = models.CharField(max_length=45,null=True, blank=True)
rate = models.DecimalField(max_digits=12, decimal_places=2, default=Decimal(0.00), null=True, blank=True)
pub_date = models.DateField(blank=True, null=True)
vendor = models.ForeignKey(Party, blank=True, null=True)
request_id = models.ForeignKey(Request, blank=True, null=True, related_name='requestprint')
def __str__(self):
return self.particular
this is my api views:
class PrintRequestAPIView(ListBulkCreateAPIView):
serializer_class = RequestPrintSerializer
this is my serializer:
class RequestPrintSerializer(serializers.ModelSerializer):
order_media = OrderMediaSerializer(required=False)
class Meta:
model = RequestPrintProduction
fields = '__all__'
def create(self, validated_data):
service_request = Request()
service_request.save()
validated_data['request_id'] = service_request
order_media = validated_data.pop('order_media')
print(order_media)
online_service_request = self.Meta.model.objects.create(**data)
order_media['request_id'] = service_request
order_media = OrderMedia.objects.create(**order_media)
return online_service_request
I expect to post array's data successfully.

Answer 1

Let's try to arrange the post data like below. And then whenever you are initializing RequestPrintSerializer for this request initialize the serializer with many=True. Hope it helps. Good lucks.
{
"order_media": {
"client_employee": "4",
"client": "63",
"narration": "Print ad",
"vendor": "68",
"total_amount": "2590.00",
"discount_rate_client": "10.00",
"discount_amount_client": "259.00",
"service_percentage": "10.00",
"service_amount": "259.00",
"client_vat": "388.50",
"total_receivable": "2978.50"
},
"request_print_production": [
{
"pub_date" : "2019-04-03",
"particular": "Banner",
"inch_first": "4",
"inch_second": "4",
"size": "16.00",
"quantity": "5",
"rate": "10"
},
{
"pub_date" : "2019-04-03",
"particular": "Poster",
"inch_first": "5",
"inch_second": "5",
"size": "25.00",
"quantity": "5",
"rate": "10"
},
{
"pub_date" : "2019-04-03",
"particular": "Plastic Banner",
"inch_first": "3",
"inch_second": "3",
"size": "9.00",
"quantity": "6",
"rate": "10"
}
]
}

Answer 2

It seems like you have a char field in your database, but want to post an array to DRF. In fact, as the comments mentioned, this is an issue with nearly all your fields. You seem to get around this by just passing strings in everywhere.
Without database support this won't work directly. However, if you do really want to do this then you are going to have to do some of the work in your own code. There are custom fields for this out there somewhere, probably, but I've never seen 'em.
JSON Post Only
Here's an easy way to go about doing that:
Declare the field on your serializer directly as a ListField
In the 'validate' function, convert to a string (csv, json.dumps, etc)
Note that I'm not checking for empty values, settings defaults, etc. Please read the documentation (and source) for ListField on your own.
class Serializer(ModelSerializer):
particular = ListField(child=CharField(max_length=10))
def validate_particular(self, value):
"""Convert the list to a json string, and do extra validation if needed"""
return json.dumps(value)
Input & Output (Post & Get)
If you are using this both for input and output, and want to return a list from your model, you are going to need to make a custom field:
class ListAsJsonField(fields.ListField):
"""
Converts an incoming list of string values to json.
This field is _very_ primitive, lots of edge cases may break it.
"""
child = fields.CharField(min_length=1) # always use a char field
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
def to_representation(self, data):
"""Convert to our output representation. Assumes input is always valid json now"""
return json.loads(data)
def to_internal_value(self, data):
"""Convert to the internal value -> database (and validated_data)"""
return json.dumps(data)
class MySerializer(serializers.ModelSerializer):
particular = ListAsJsonField(required=True, min_length=1)
...
Notes:
Some databases like postgres have a custom JSON field & Array field. Django ships with fields for those in django.contrib.postgres. Using these would imply you also want to fix your other model issues.
What the heck is ListBulkCreateAPIView?