HTTP 500 error in Django while getting data using AJAX

Question

Following is my views.py function, that takes in customer key as AJAX input from user and checks the database and returns the customer name.

def bill(request):

if request.method == 'POST':
    customerkey = request.POST.get('customer_code')
    response_data['name'] = Customer.object.name(customer_key=customerkey)
    json = json.dumps(response_data)
    return HttpResponse(json, mimetype='application/json')
return render(request, 'bill/invoicing.html')

Following is the model in models. py:

class Customer (models.Model):
name=models.CharField(max_length=300, unique=True)
zone=models.ForeignKey(Zone,related_name='customer_zone', verbose_name='Zone')
slug=models.SlugField(max_length=300)
customer_key=models.CharField(max_length = 10, unique=True)
address=models.TextField(unique=True)
phone_no=models.TextField
details=models.TextField(blank=True)
object = models.Manager()

def get_absolute_url(self):
    return reverse('billbrain:master_detail', kwargs={'detail':self.slug})


def save(self, *args, **kwargs):
    if not self.id:
        self.slug=slugify(self.name)

    super(Customer, self).save(*args, **kwargs)


class Meta:
    ordering = ('name',)


def __str__(self):
    return self.name

However, after the AJAX call I'm getting a HTTP 500 error.

I dont know why. Can someone please elaborate.

For your further needful, following is the AJAX call to the django view.

(function() {
    console.log("AJAX about to start") // sanity check
    $.ajax({
        url : "", 
        type : "POST", 
        data : { customer_code: input,
                 'csrfmiddlewaretoken': csrf_token}, // data sent with the post request

                // handle a successful response
        success : function(json) {
            console.log(json); // log the returned json to the console
            console.log("success"); // another sanity check
        },

        });
}());

Edit 1

Following is the error shown in the console:

POST http://localhost:8000/master/sellbill/ 500 (INTERNAL SERVER ERROR)
send @ jquery.min.js:4
n.extend.ajax @ jquery.min.js:4
(anonymous function) @ script.js:260
(anonymous function) @ script.js:277
n.event.dispatch @ jquery.min.js:3
r.handle @ jquery.min.js:3

The anonymous function is the ajax function, that I've copied above

Update

Following is the traceback, after I put customer data and the AJAX call starts:

UnboundLocalError at /master/sellbill/
local variable 'json' referenced before assignment

Request Method: POST
Request URL: http://localhost:8000/master/sellbill/
Django Version: 1.8.6
Python Executable: C:\Users\Ganguly          PC\Desktop\DjangoStudy\my_env\Scripts\python.exe
Python Version: 3.5.1
Python Path: ['C:\\Users\\Ganguly PC\\Desktop\\DjangoStudy\\billinv',  'C:\\Users\\Ganguly PC\\Desktop\\DjangoStudy\\my_env\\lib\\site-packages\\pytz- 2015.7-py3.5.egg', 'C:\\Users\\Ganguly  PC\\Desktop\\DjangoStudy\\my_env\\Scripts\\python35.zip', 'C:\\Users\\Ganguly  PC\\Desktop\\DjangoStudy\\my_env\\DLLs', 'C:\\Users\\Ganguly PC\\Desktop\\DjangoStudy\\my_env\\lib', 'C:\\Users\\Ganguly PC\\Desktop\\DjangoStudy\\my_env\\Scripts', 'c:\\python35-32\\Lib',  'c:\\python35-32\\DLLs', 'C:\\Users\\Ganguly PC\\Desktop\\DjangoStudy\\my_env', 'C:\\Users\\Ganguly PC\\Desktop\\DjangoStudy\\my_env\\lib\\site-packages']
Server time: Sun, 3 Apr 2016 10:11:43 +0000
Installed Applications:
('django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'billbrain',
 'bootstrap_themes')
 Installed Middleware:
('django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware',
 'django.middleware.security.SecurityMiddleware')

Traceback:
File "C:\Users\Ganguly PC\Desktop\DjangoStudy\my_env\lib\site-packages\django\core\handlers\base.py" in get_response
132.                     response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "C:\Users\Ganguly PC\Desktop\DjangoStudy\billinv\billbrain\views.py" in  bill
118.        json = json.dumps(response_data)

Exception Type: UnboundLocalError at /master/sellbill/
Exception Value: local variable 'json' referenced before assignment
Request information:
GET: No GET data

POST:
customer_code = 'FR'
csrfmiddlewaretoken = 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'

FILES: No FILES data

COOKIES:
csrftoken = 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX'
toShowIxigo = '1'

Answer 1

Your code is not working properly because of this line:

response_data['name'] = Customer.objects.name(customer_key=customerkey)

Is should be something like:

response_data['name'] = Customer.objects.get(customer_key=customerkey).name

I would suggest to catch exception if the object is not found to avoid further errors.

try:
    customer = Customer.objects.get(customer_key=customerkey)
    response_data['name'] = customer.name
except Customer.DoesNotExists:
    show_error_response()

Update : I just noticed that you haven't defined response_data dict and are directly assigning values to 'name' key. You should define it before populating it.

response_data = {}
response_data['name'] = Customer.objects.name(customer_key=customerkey)