63 lines
2.2 KiB
Python
63 lines
2.2 KiB
Python
"""
|
|
This module collects helper functions and classes that "span" multiple levels
|
|
of MVC. In other words, these functions/classes introduce controlled coupling
|
|
for convenience's sake.
|
|
"""
|
|
|
|
from django.template import loader
|
|
from django.http import HttpResponse, Http404
|
|
from django.db.models.manager import Manager
|
|
from django.db.models.query import QuerySet
|
|
|
|
def render_to_response(*args, **kwargs):
|
|
"""
|
|
Returns a HttpResponse whose content is filled with the result of calling
|
|
django.template.loader.render_to_string() with the passed arguments.
|
|
"""
|
|
return HttpResponse(loader.render_to_string(*args, **kwargs))
|
|
load_and_render = render_to_response # For backwards compatibility.
|
|
|
|
def _get_queryset(klass):
|
|
"""
|
|
Returns a QuerySet from a Model, Manager, or QuerySet. Created to make
|
|
get_object_or_404 and get_list_or_404 more DRY.
|
|
"""
|
|
if isinstance(klass, QuerySet):
|
|
return klass
|
|
elif isinstance(klass, Manager):
|
|
manager = klass
|
|
else:
|
|
manager = klass._default_manager
|
|
return manager.all()
|
|
|
|
def get_object_or_404(klass, *args, **kwargs):
|
|
"""
|
|
Uses get() to return an object, or raises a Http404 exception if the object
|
|
does not exist.
|
|
|
|
klass may be a Model, Manager, or QuerySet object. All other passed
|
|
arguments and keyword arguments are used in the get() query.
|
|
|
|
Note: Like with get(), an AssertionError will be raised if more than one
|
|
object is found.
|
|
"""
|
|
queryset = _get_queryset(klass)
|
|
try:
|
|
return queryset.get(*args, **kwargs)
|
|
except queryset.model.DoesNotExist:
|
|
raise Http404('No %s matches the given query.' % queryset.model._meta.object_name)
|
|
|
|
def get_list_or_404(klass, *args, **kwargs):
|
|
"""
|
|
Uses filter() to return a list of objects, or raise a Http404 exception if
|
|
the list is empty.
|
|
|
|
klass may be a Model, Manager, or QuerySet object. All other passed
|
|
arguments and keyword arguments are used in the filter() query.
|
|
"""
|
|
queryset = _get_queryset(klass)
|
|
obj_list = list(queryset.filter(*args, **kwargs))
|
|
if not obj_list:
|
|
raise Http404('No %s matches the given query.' % queryset.model._meta.object_name)
|
|
return obj_list
|