(Django) Send POST ID back to the Client

Question

I'm new to Django and I'm trying to create a somewhat basic API. But one thing that has been bugging me is how to create a callback function for when certain (asynchronous) events occur.

For example, one of my simplest cases is for when the client sends a POST request. I would like to send back to him the ID of that request in the DB. How would I do that?

My code mostly follows William S. Vincent's Django for APIs book with minor modifications.

The most important parts are:

models.py:

from django.db import models

class SegmentcliApi(models.Model): 

    request_id = models.AutoField(primary_key = True)
    database = models.CharField(max_length = 100)
    created_at = models.DateTimeField(auto_now_add = True)
    updated_at = models.DateTimeField(auto_now = True)

    def __str__(self): 

        return f'DB Request to {self.database}: created at {self.created_at}'

serializers.py:

from rest_framework import serializers 
from .models import SegmentcliApi 

class SegmentcliApiSerializer(serializers.ModelSerializer):

    class Meta: 

        fields = (
            'request_id',
            'database',
            'created_at',
            'updated_at',    
        ) 

        model = SegmentcliApi

views.py:

from rest_framework import generics 
from .models import SegmentcliApi
from .serializers import SegmentcliApiSerializer 

class SegmentcliApiList(generics.ListCreateAPIView):

    queryset = SegmentcliApi.objects.all() 
    serializer_class = SegmentcliApiSerializer 

class SegmentcliApiDetail(generics.RetrieveUpdateDestroyAPIView): 

    queryset = SegmentcliApi.objects.all() 
    serializer_class = SegmentcliApiSerializer

Answer 1

I would suggest starting to look at Django Forms and specifically Model Form, which is what I think SegmentcliApiSerializer is supposed to be. Then, I'm not sure how your urls.py is set up to work with your app, but in your template, the form would be something like:

<form action="{% url 'name_of_your_url_to_get_to_view_method' %}" method="POST">
    {% csrf_token %}
        {{ form }} 
    <button type="submit">BUTTON</button>
</form>

and view.py would be something like this:

def yourViewMethod(request):
    if(request.method == "POST"):
        form = SegmentcliApiSerializer(request.POST)
        if(form.is_valid()):
            form.save()
            savedId = request.POST.get("request_id")
            return render(request, "yourFolder/yourHtmlFile.html", {"savedId": savedId})
    else:
        form = SegmentcliApiSerializer()
    return render(request, "yourFolder/yourHtmlFile.html", {"form": form})

and then, in whatever yourHtmlFile.html is, you can use

{{ savedId }}

somewhere to display it. I think that's what you're asking.

EDIT: Fixed so it got the value correctly.

Answer 2

I can't comment cause I don't have enough reputation but, with respect to @marsonfire's answer, if you want to have only simple JSON response you can use JsonResponse instead of render.

So, you'd have something like return JsonResponse({"savedId": savedId})

Answer 3

In your views.py, more specifically, in the CreateApiView or ListCreateApiView classes, you can override the create method such that you can get a specific response from post request.

The create method comes from the CreateModelMixin class, which is inherited by the ListCreateAPIView, and which is in turn inherited by your specific Django model.

So follow the steps below:

from rest_framework import status
from rest_framework.response import Response

class SegmentcliApiList(generics.ListCreateAPIView):

    queryset = SegmentcliApi.objects.all() 
    serializer_class = SegmentcliApiSerializer 

    def create(self, request, *args, **kwargs):

        serializer = self.get_serializer(data=request.data)
        serializer.is_valid(raise_exception=True)
        self.perform_create(serializer)
        headers = self.get_success_headers(serializer.data)

        # Original Response (inside the `CreateModelMixin` class)
        # return Response(
        #     serializer.data, 
        #     status=status.HTTP_201_CREATED, 
        #     headers=headers
        # )

        # We will replace the original response with this line 
        return Response(
            {'id': serializer.data.get('request_id')},
            status=status.HTTP_201_CREATED, 
            headers=headers
        )
        # serailizer.data is the created object in a JSON format 

This works for me. If it is not working for you, tell me what you're getting in comments. If it works for you, please accept the answer.