如何通过javascript文件中的ajax调用在views.py中调用特定功能？

Question

In Django we map URLs to functions in views.py. If we do an ajax call then we need to mention url in ajax call but that will call the function mapped to that url. I want to call specific function from views.py via ajax call? What should I do so that I can call any function in views.py via AJAX call without changing url?

views.py

def index(request):
    codes=Code.objects.all()[:10]
    context={
        'name': 'KD',
        'codes': codes
    }
    return render(request,'coding/index.html',context)


def details(request):
    code=Code.objects.get(1)
    context={
        'code': code
    }
    return render(request, 'coding/details.html', context)

urls.py

from django.contrib import admin
from django.urls import path,include
from . import views

urlpatterns = [
    path('',views.index, name="index" ),
    path('details',views.details, name="details" ),
];

javascript

<script type="text/javascript">
   $(document).ready(function() {
       $("#tests").submit(function(event){
       event.preventDefault();
            $.ajax({
                 type:"POST",
                 url:"/details/",  // what changes should be done so that I can call other function in views.py?
                 data: {
                        'video': $('#tests').val() 
                        },
                 success: function(){
                     $('#message').html("<h2>Code Submitted!</h2>") 
                    }
            });
            return false;
       });

    });
</script>

Answer 1

Just wrap function call in view and use it like usual view. For example, you have a function:

   def print_hello():
       print("Hello!")

You should create view:

   def print_hello_view(request):
       print_hello()
       return HttpResponse(status=200)

And add it into urls:

    path('print-hello',views.print_hello_view, name="print_hello_view"),

And in template replace ajax url by new endpoint:

    {% url 'print_hello_view' %}

If you want have possibility to choose function you should add some condition.

Answer 2

I think what Nikitka was saying is that you can listen for the POST request in the details view and use it to run your other python function. Try something like the following:

def details(request):
    # Check if there was a POST request that contains the 'video' key
    if 'video' in request.POST:
        # Run your python script here.

    code=Code.objects.get(1)
    context={
        'code': code
    }
    return render(request, 'coding/details.html', context)

For further reading I would like to recommend Vitor Freitas's blog .

Answer 3

I'm not sure why you would want to do this, and from a security perspective it's a bad idea. Allowing access to arbitrary functions could be exploitable, so you should avoid it.

The ajax client will need to know in advance the names of the internal functions so that it can invoke them, and possibly also know what arguments can be passed to the function. If the client has that information, then you might as well explicitly expose the functions in urls.py and leave it at that.

Having made my objection, you could implement a dispatch view function that accepts the request and delegates to a function specified in the request using globals()['function_name'] .

Assuming that the functions to be called are view functions that return an appropriate value (rendered HttpResponse , JSON, etc.) your view might look like this:

def call_named_function(request, function_name):
    try:
        return globals()[function_name](request)
    except KeyError:
        return JsonResponse({'error': True, 'message': 'Function {!r} not found'.format(function_name)}, status=404)
    except Exception, exc:
        return JsonResponse({'error': True, 'message': 'Exception calling function {!r}: {}'.format(function_name, exc)}, status=500)

Add a route to urls.py to capture the function name and call the view function:

path('call/<function_name>', views.call_named_function, name='call'),

Now you can add view functions to your code, or import them from another module, and call them using the function name appended to the URL:

http://127.0.0.1:8000/call/function_1
http://127.0.0.1:8000/call/some_function

etc.

---

I think that it's easier to use the above, but if you do not want to change the URL, then you will have to add something to the body of the POST request that specifies the name of the function to call:

def call_named_function(request):
    try:
        function_name = request.POST['function_name']
        return globals()[function_name](request)
    except KeyError:
        return JsonResponse({'error': True, 'message': 'Function {!r} not found'.format(function_name)}, status=404)
    except Exception as exc:
        return JsonResponse({'error': True, 'message': 'Exception calling function {!r}: {}'.format(function_name, exc)}, status=500)

with route:

path('call', views.call_named_function, name='call'),

and POST the name of the function to call in the request with name 'function_name' .

You could also POST arguments as JSON encoded lists for positional arguments and JSON encoded dicts for keyword arguments.