Display form errors with django and ajax

问题

I have a contact form through which users would be able to contact me. I am using django with ajax, and it works fine if there's no error. I would like to show the errors if there's any like it displays above the input fields and not just the errors, but both the input and the errors. It does however differentiate between the success and error result, as the ajax request was successful. But I need to display the actual form errors. How do I that? Your help will be very much appreciated. Thank you.

views:

def contact(request):
    if request.is_ajax() and request.POST:
        form = ContactForm(request.POST)
        if form.is_valid():
            new_contact = form.save()
            data = {
                'result': 'success',
                'message': 'Message Sent.'
            }
            return JsonResponse(data)
        else:
            data = {
                'result': 'error',
                'message': 'Form invalid',
                'form': 'oops.'
            }
            return JsonResponse(data)
    else:
        form = ContactForm()
        return render(request, 'public_contact.html', {
            'form': form
        })

js:

contact_right_form.find('#submit').on('click', function(event) {
    event.preventDefault();
    $.ajax({
        type: contact_right_form.attr('method'),
        url: '/contact/',
        data: contact_right_form.serialize(),
        dataType: 'json',
        success: function(data) {
            if ( data.result == 'success') {
                contact_right_message_sent.text(data.message);
                contact_right_message_sent.show();
            }
            else {
                contact_right_message_sent.text(data.message);
                contact_right_message_sent.show();
            }
        },
        error: function() {
            contact_right_message_sent.text('Sorry! Something went wrong.')
        }
    });
})

Update

I would like to display the errors like the below as it normally does without ajax:

回答1:

as an example

django form returns errors with json format using form.errors.as_json(). assume:

{
    "sender": [
         {
           "message": "Enter a valid email address.", 
           "code": "invalid"
         }
    ],

    "subject": [
          {
            "message": "This field is required.", 
            "code": "required"
          }
    ]
}

after that, ajax get a response (in success: function(data) {}. assume already become an object:

    data = {
    "sender": [
    {
        "message": "Enter a valid email address.", 
      "code": "invalid"
    },
    {
        "message": "Enter a .", 
      "code": "invalid"
    }
  ], 
   "subject": [
    {
        "message": "This field is required.", 
      "code": "required"
    }
  ]
};

and you're already renders previous form, assume:

<input type="text" name="sender"> <br>
<input type="text" name="subject"> <br>
<button>Submit</button>

and to render these messages, you can write scripts in the click events:

// in ajax success (event click)
if ($("input").next('p').length) $("input").nextAll('p').empty();
    for (var name in data) {
    for (var i in data[name]) {
      // object message error django
      var $input = $("input[name='"+ name +"']");
      $input.after("<p>" + data[name][i].message + "</p>");
    }
  }

simulation example:

// simulation example, Data obtained from ajax response

var data = {
	"sender": [
  	{
    	"message": "Enter a valid email address.", 
      "code": "invalid"
    },
    {
    	"message": "Enter a .", 
      "code": "invalid"
    }
  ],
	"subject": [
  	{
    	"message": "This field is required.", 
      "code": "required"
    }
  ]
};

$("button").on("click", function() {
	if ($("input").next('p').length) $("input").nextAll('p').empty();
	for (var name in data) {
    for (var i in data[name]) {
      // object message error django
      var $input = $("input[name='"+ name +"']");
      $input.after("<p>" + data[name][i].message + "</p>");
    }
  }
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input type="text" name="sender"> <br>
<input type="text" name="subject"> <br>
<button>Submit</button>

回答2:

You need to define status_code argument for JsonResponse.

return JsonResponse(data, status_code=400)

This way it will end up in the error callback in $.ajax.

回答3:

While you could return all json back and add the errors to the fields, another approach would be to render a partial template of just the form and return the html back to the browser. You would then just replace the form with the returned form.

I'm not saying this is the best thing to do, but it is one approach.

For example, you have /form.html and you include it on the page

{% include 'form.html' %}

then in your form_invalid method, return the rendered html string

return render(self.request, 'form.html', {'form' : form}, status=500)

then in your JS error method, replace the form on the page with the html returned from the server.

来源：https://stackoverflow.com/questions/34457696/display-form-errors-with-django-and-ajax