Creating a JSON response using Django and Python

Question

I'm trying to convert a server side Ajax response script into a Django HttpResponse, but apparently it's not working.

This is the server-side script:

/* RECEIVE VALUE */
$validateValue=$_POST['validateValue'];
$validateId=$_POST['validateId'];
$validateError=$_POST['validateError'];

/* RETURN VALUE */
$arrayToJs = array();
$arrayToJs[0] = $validateId;
$arrayToJs[1] = $validateError;

if($validateValue =="Testuser"){  // Validate??
    $arrayToJs[2] = "true";       // RETURN TRUE
    echo '{"jsonValidateReturn":'.json_encode($arrayToJs).'}';  // RETURN ARRAY WITH success
}
else{
    for($x=0;$x<1000000;$x++){
        if($x == 990000){
            $arrayToJs[2] = "false";
            echo '{"jsonValidateReturn":'.json_encode($arrayToJs).'}';   // RETURNS ARRAY WITH ERROR.
        }
    }
}

And this is the converted code

def validate_user(request):
    if request.method == 'POST':
        vld_value = request.POST.get('validateValue')
        vld_id = request.POST.get('validateId')
        vld_error = request.POST.get('validateError')

        array_to_js = [vld_id, vld_error, False]

        if vld_value == "TestUser":
            array_to_js[2] = True
            x = simplejson.dumps(array_to_js)
            return HttpResponse(x)
        else:
            array_to_js[2] = False
            x = simplejson.dumps(array_to_js)
            error = 'Error'
            return render_to_response('index.html',{'error':error},context_instance=RequestContext(request))
    return render_to_response('index.html',context_instance=RequestContext(request))

I'm using simplejson to encode the Python list (so it will return a JSON array). I couldn't figure out the problem yet. But I think that I did something wrong about the 'echo'.

Answer 1

I usually use a dictionary, not a list to return JSON content.

import json

from django.http import HttpResponse

response_data = {}
response_data['result'] = 'error'
response_data['message'] = 'Some error message'

Pre-Django 1.7 you'd return it like this:

return HttpResponse(json.dumps(response_data), content_type="application/json")

For Django 1.7+, use JsonResponse as shown in this SO answer like so :

from django.http import JsonResponse
return JsonResponse({'foo':'bar'})

Answer 2

New in django 1.7

you could use JsonResponse objects.

from the docs:

from django.http import JsonResponse
return JsonResponse({'foo':'bar'})

Answer 3

I use this, it works fine.

from django.utils import simplejson
from django.http import HttpResponse

def some_view(request):
    to_json = {
        "key1": "value1",
        "key2": "value2"
    }
    return HttpResponse(simplejson.dumps(to_json), mimetype='application/json')

Alternative:

from django.utils import simplejson

class JsonResponse(HttpResponse):
    """
        JSON response
    """
    def __init__(self, content, mimetype='application/json', status=None, content_type=None):
        super(JsonResponse, self).__init__(
            content=simplejson.dumps(content),
            mimetype=mimetype,
            status=status,
            content_type=content_type,
        )

In Django 1.7 JsonResponse objects have been added to the Django framework itself which makes this task even easier:

from django.http import JsonResponse
def some_view(request):
    return JsonResponse({"key": "value"})

Answer 4

Since Django 1.7 you have a standard JsonResponse that's exactly what you need:

from django.http import JsonResponse
...
return JsonResponse(array_to_js, safe=False)

You don't even need to json.dump your array.

Answer 5

For those who use Django 1.7+

from django.http import JsonResponse

def your_view(request):
    json_object = {'key': "value"}
    return JsonResponse(json_object)

official docs

Answer 6

from django.http import HttpResponse
import json

class JsonResponse(HttpResponse):
    def __init__(self, content={}, mimetype=None, status=None,
             content_type='application/json'):
        super(JsonResponse, self).__init__(json.dumps(content), mimetype=mimetype,
                                           status=status, content_type=content_type)

And in the view:

resp_data = {'my_key': 'my value',}
return JsonResponse(resp_data)

Answer 7

With Django Class-based views you can write:

from django.views import View
from django.http import JsonResponse

class JsonView(View):
    def get(self, request):
        return JsonResponse({'some': 'data'})

and with Django-Rest-Framework you can write:

from rest_framework.views import APIView
from rest_framework.response import Response

class JsonView(APIView):
    def get(self, request):
        return Response({'some': 'data'})

Answer 8

You'll want to use the django serializer to help with unicode stuff:

from django.core import serializers

json_serializer = serializers.get_serializer("json")()
    response =  json_serializer.serialize(list, ensure_ascii=False, indent=2, use_natural_keys=True)
    return HttpResponse(response, mimetype="application/json")

Answer 9

Its very convenient with Django version 1.7 or higher as you have the JsonResponse class, which is a subclass of HttpResponse.

from django.http import JsonResponse
    def profile(request):
        data = {
            'name': 'Raghav',
            'location': 'India',
            'is_active': False,
            'count': 28
        }
        return JsonResponse(data)

For older versions of Django, you must use an HttpResponse object.

import json
from django.http import HttpResponse

def profile(request):
    data = {
        'name': 'Raghav',
        'location': 'India',
        'is_active': False,
        'count': 28
    }
    dump = json.dumps(data)
    return HttpResponse(dump, content_type='application/json')

Answer 10

How to use google app engine with ajax (json)?

Code Javascript with JQuery:

$.ajax({
    url: '/ajax',
    dataType : 'json',
    cache: false,
    success: function(data) {
        alert('Load was performed.'+data.ajax_resp);
    }
});

Code Python

class Ajax(webapp2.RequestHandler):
    def get(self):
        my_response = {'ajax_resp':'Hello, webapp World!'}
        datos = json.dumps(my_response)

        self.response.headers.add_header('content-type', 'application/json', charset='utf-8')
        self.response.out.write(datos)

Answer 11

Django code views.py:

def view(request):
    if request.method == 'POST':
        print request.body
        data = request.body
        return HttpResponse(json.dumps(data))

HTML code view.html:

<!DOCTYPE html>
<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script>
$(document).ready(function(){
    $("#mySelect").change(function(){
        selected = $("#mySelect option:selected").text()
        $.ajax({
            type: 'POST',
            dataType: 'json',
            contentType: 'application/json; charset=utf-8',
            url: '/view/',
            data: {
                    'fruit': selected
                  },
            success: function(result) {
                        document.write(result)
                    }
    });
  });
});
</script>
</head>
<body>

<form>
    {{data}}
    <br>
Select your favorite fruit:
<select id="mySelect">
  <option value="apple" selected >Select fruit</option>
  <option value="apple">Apple</option>
  <option value="orange">Orange</option>
  <option value="pineapple">Pineapple</option>
  <option value="banana">Banana</option>
</select>
</form>
</body>
</html>

Answer 12

First import this:

from django.http import HttpResponse

If you have the JSON already:

def your_method(request):
    your_json = [{'key1': value, 'key2': value}]
    return HttpResponse(your_json, 'application/json')

If you get the JSON from another HTTP request:

def your_method(request):
    response = request.get('https://www.example.com/get/json')
    return HttpResponse(response, 'application/json')

Answer 13

This is my preferred version using a class based view. Simply subclass the basic View and override the get()-method.

import json

class MyJsonView(View):

    def get(self, *args, **kwargs):
        resp = {'my_key': 'my value',}
        return HttpResponse(json.dumps(resp), mimetype="application/json" )

Answer 14

Use JsonResponse

from django.http import JsonResponse

Answer 15

In View use this:

form.field.errors|striptags

for getting validation messages without html

Answer 16

Most of these answers are out of date. JsonResponse is not recommended because it escapes the characters, which is usually undesired. Here's what I use:

views.py (returns HTML)

from django.shortcuts import render
from django.core import serializers

def your_view(request):
    data = serializers.serialize('json', YourModel.objects.all())
    context = {"data":data}
    return render(request, "your_view.html", context)

views.py (returns JSON)

from django.core import serializers
from django.http import HttpResponse

def your_view(request):
    data = serializers.serialize('json', YourModel.objects.all())
    return HttpResponse(data, content_type='application/json')

Bonus for Vue Users

If you want to bring your Django Queryset into Vue, you can do the following.

template.html

<div id="dataJson" style="display:none">
{{ data }}
</div>

<script>
let dataParsed = JSON.parse(document.getElementById('dataJson').textContent);
var app = new Vue({
  el: '#app',
  data: {
    yourVariable: dataParsed,
  },
})
</script>