Source code for django_select2.views
"""JSONResponse views for model widgets."""
from django.core import signing
from django.core.signing import BadSignature
from django.http import Http404, JsonResponse
from django.utils.module_loading import import_string
from django.views.generic.list import BaseListView
from .cache import cache
from .conf import settings
[docs]
class AutoResponseView(BaseListView):
"""
View that handles requests from heavy model widgets.
The view only supports HTTP's GET method.
"""
[docs]
def get(self, request, *args, **kwargs):
"""
Return a :class:`.django.http.JsonResponse`.
Example::
{
'results': [
{
'text': "foo",
'id': 123
}
],
'more': true
}
"""
self.widget = self.get_widget_or_404()
self.term = kwargs.get("term", request.GET.get("term", ""))
self.object_list = self.get_queryset()
context = self.get_context_data()
return JsonResponse(
{
"results": [
{"text": self.widget.label_from_instance(obj), "id": obj.pk}
for obj in context["object_list"]
],
"more": context["page_obj"].has_next(),
},
encoder=import_string(settings.SELECT2_JSON_ENCODER),
)
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def get_queryset(self):
"""Get QuerySet from cached widget."""
kwargs = {
model_field_name: self.request.GET.get(form_field_name)
for form_field_name, model_field_name in self.widget.dependent_fields.items()
}
kwargs.update(
{
f"{model_field_name}__in": self.request.GET.getlist(
f"{form_field_name}[]", []
)
for form_field_name, model_field_name in self.widget.dependent_fields.items()
}
)
return self.widget.filter_queryset(
self.request,
self.term,
self.queryset,
**{k: v for k, v in kwargs.items() if v},
)
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def get_paginate_by(self, queryset):
"""Paginate response by size of widget's `max_results` parameter."""
return self.widget.max_results
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def get_widget_or_404(self):
"""
Get and return widget from cache.
Raises:
Http404: If if the widget can not be found or no id is provided.
Returns:
ModelSelect2Mixin: Widget from cache.
"""
field_id = self.kwargs.get("field_id", self.request.GET.get("field_id", None))
if not field_id:
raise Http404('No "field_id" provided.')
try:
key = signing.loads(field_id)
except BadSignature:
raise Http404('Invalid "field_id".')
else:
cache_key = f"{settings.SELECT2_CACHE_PREFIX}{key}"
widget_dict = cache.get(cache_key)
if widget_dict is None:
raise Http404("field_id not found")
if widget_dict.pop("url") != self.request.path:
raise Http404("field_id was issued for the view.")
qs, qs.query = widget_dict.pop("queryset")
self.queryset = qs.all()
widget_dict["queryset"] = self.queryset
widget_cls = widget_dict.pop("cls")
return widget_cls(**widget_dict)