def json_index(request):
"""
Answer to ajax requests of the client returning
JSON serialized data.
"""
# give a response only if this is an ajax request
if request.is_ajax():
# get application label and object name
app_label = request.GET.get('app_label')
object_name = request.GET.get('object_name')
if app_label and object_name:
from django.db.models.loading import get_model
# get the model
model = get_model(app_label, object_name)
if model is not None:
from django.utils import simplejson
# get the lookup dict
lookup_string = request.GET.get('lookup_string', '')
lookup_dict = utils.stringToLookup(lookup_string)
# get the select related part
select_related = utils._cleanValue(
request.GET.get('select_related'))
# get the queryset
objects = utils.getObjects(model, lookup_dict, select_related)
# get the raw data and dump the json
raw_data = [(i.pk, unicode(i)) for i in objects]
data = simplejson.dumps(raw_data)
# return data with the right content type
return HttpResponse(data, content_type="application/json")
raise Http404
def _getAllChoices(self, value):
value = value or []
choices = list(self.choices)
# convert to unicode for safe comparisong during a ValidationError
choices_keys = [unicode(i[0]) for i in choices]
objects_to_fetch = []
for i in value:
if not unicode(i) in choices_keys:
objects_to_fetch.append(i)
if objects_to_fetch:
objects = utils.getObjects(self.model, {"pk__in": objects_to_fetch}, self.select_related)
for obj in objects:
choices.append((obj.pk, unicode(obj)))
choices.sort(key=operator.itemgetter(1))
return choices
def __init__(
self,
model,
lookups,
default_index=0,
select_related=None,
widget=FilteredSelectMultiple,
filter_widget=SelectBoxFilter,
*args,
**kwargs
):
"""
model: the related model
lookups: a sequence of (label, lookup_dict) that tells how to
filter the objects
e.g. (
('active', {'is_active': True}),
('inactive', {'is_active': False}),
)
you may specify what you want in lookup_dict, give multiple
filter lookups for the same choice and also set a choice that
gets all unfiltered objects
e.g. (
('some stuff', {
'field1__startswith': 'a',
'field2': 'value'
}),
('all stuff', {}),
)
default_index: the index of the lookup sequence that will
be the default choice when the field is initially displayed.
set to None if you want the widget to start empty
select_related: if not None the resulting querydict is performed
using select_related(select_related), allowing foreign keys
to be retrieved (e.g. useful when the unicode representation
of the model objects contains references to foreign keys)
It is possible to pass all the other args and kwargs accepted by
the django field class.
"""
# get the default index and queryset
# queryset is empty if default index is None
if default_index is None:
queryset = model.objects.none()
else:
lookups_list = utils.getLookups(lookups)
if default_index >= len(lookups_list):
default_index = 0
lookup_dict = lookups_list[default_index][1]
# get the queryset
queryset = utils.getObjects(model, lookup_dict, select_related)
# call the parent constructor
super(AjaxManyToManyField, self).__init__(queryset, widget=widget, *args, **kwargs)
# populate widget with some data
self.widget.lookups = self.lookups = lookups
self.widget.model = self.model = model
self.widget.select_related = select_related
self.widget.filter_widget = filter_widget()
self.widget.default_index = default_index
