Banktransfer: Big import refactoring

src/pretix/base/views/async.py

@@ -0,0 +1,134 @@
+import logging
+
+from django.conf import settings
+from django.contrib import messages
+from django.http import JsonResponse
+from django.shortcuts import redirect, render
+from django.utils.translation import ugettext as _
+
+logger = logging.getLogger('pretix.base.async')
+
+
+class AsyncAction:
+    task = None
+    success_url = None
+    error_url = None
+
+    def do(self, *args):
+        if settings.HAS_CELERY:
+            from pretix.celery import app
+
+            if hasattr(self.task, 'task') and isinstance(self.task.task, app.Task):
+                return self._do_celery(args)
+            else:
+                raise TypeError('Method has no task attached')
+        else:
+            return self._do_sync(args)
+
+    def get_success_url(self, value):
+        return self.success_url
+
+    def get_error_url(self):
+        return self.error_url
+
+    def get_check_url(self, task_id, ajax):
+        return self.request.path + '?async_id=%s' % task_id + ('&ajax=1' if ajax else '')
+
+    def get(self, request, *args, **kwargs):
+        if 'async_id' in request.GET and settings.HAS_CELERY:
+            return self.get_result(request)
+        return self.http_method_not_allowed(request)
+
+    def _return_celery_result(self, res, timeout=.5):
+        import celery.exceptions
+
+        if not res.ready():
+            try:
+                res.get(timeout=timeout)
+            except celery.exceptions.TimeoutError:
+                pass
+        ready = res.ready()
+        data = {
+            'async_id': res.id,
+            'ready': ready
+        }
+        if ready:
+            if res.successful() and not isinstance(res.info, Exception):
+                smes = self.get_success_message(res.info)
+                if smes:
+                    messages.success(self.request, smes)
+                # TODO: Do not store message if the ajax client stats that it will not redirect
+                # but handle the mssage itself
+                data.update({
+                    'redirect': self.get_success_url(res.info),
+                    'message': str(self.get_success_message(res.info))
+                })
+            else:
+                messages.error(self.request, self.get_error_message(res.info))
+                # TODO: Do not store message if the ajax client stats that it will not redirect
+                # but handle the mssage itself
+                data.update({
+                    'redirect': self.get_error_url(),
+                    'message': str(self.get_error_message(res.info))
+                })
+        return data
+
+    def get_result(self, request):
+        from celery.result import AsyncResult
+
+        res = AsyncResult(request.GET.get('async_id'))
+        if 'ajax' in self.request.GET:
+            return JsonResponse(self._return_celery_result(res, timeout=0.25))
+        else:
+            if res.ready():
+                if res.successful():
+                    return self.success(res.info)
+                else:
+                    return self.error(res.info)
+            return render(request, 'pretixpresale/waiting.html')
+
+    def _do_celery(self, args):
+        res = self.task.task.apply_async(args=args)
+        if 'ajax' in self.request.GET or 'ajax' in self.request.POST:
+            data = self._return_celery_result(res)
+            data['check_url'] = self.get_check_url(res.id, True)
+            return JsonResponse(data)
+        else:
+            return redirect(self.get_check_url(res.id, False))
+
+    def _do_sync(self, args):
+        try:
+            rs = getattr(self.__class__, 'task')(*args)
+            return self.success(rs)
+        except Exception as e:
+            logger.exception('Error while executing task synchronously')
+            return self.error(e)
+
+    def success(self, value):
+        smes = self.get_success_message(value)
+        if smes:
+            messages.success(self.request, smes)
+        if "ajax" in self.request.POST or "ajax" in self.request.GET:
+            return JsonResponse({
+                'ready': True,
+                'redirect': self.get_success_url(value),
+                'message': str(self.get_success_message(value))
+            })
+        return redirect(self.get_success_url(value))
+
+    def error(self, exception):
+        messages.error(self.request, self.get_error_message(exception))
+        if "ajax" in self.request.POST or "ajax" in self.request.GET:
+            return JsonResponse({
+                'ready': True,
+                'redirect': self.get_error_url(),
+                'message': str(self.get_error_message(exception))
+            })
+        return redirect(self.get_error_url())
+
+    def get_error_message(self, exception):
+        logger.error('Unexpected exception: %r' % exception)
+        return _('An unexpected error has occured.')
+
+    def get_success_message(self, value):
+        return _('The task has been completed.')