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from __future__ import unicode_literals
import datetime
import decimal
from django.db import models
from django.db.models.constants import LOOKUP_SEP
from django.db.models.deletion import Collector
from django.db.models.related import RelatedObject
from django.forms.forms import pretty_name
from django.utils import formats
from django.utils.html import format_html
from django.utils.text import capfirst
from django.utils import timezone
from django.utils.encoding import force_str, force_text, smart_text
from django.utils import six
from django.utils.translation import ungettext
from django.core.urlresolvers import reverse
def lookup_needs_distinct(opts, lookup_path):
Returns True if 'distinct()' should be used to query the given lookup path.
field_name = lookup_path.split('__', 1)[0]
field = opts.get_field_by_name(field_name)[0]
if ((hasattr(field, 'rel') and
isinstance(field.rel, models.ManyToManyRel)) or
(isinstance(field, models.related.RelatedObject) and
not field.field.unique)):
return True
return False
def prepare_lookup_value(key, value):
Returns a lookup value prepared to be used in queryset filtering.
# if key ends with __in, split parameter into separate values
if key.endswith('__in'):
value = value.split(',')
# if key ends with __isnull, special case '' and false
if key.endswith('__isnull'):
if value.lower() in ('', 'false'):
value = False
value = True
return value
def quote(s):
Ensure that primary key values do not confuse the admin URLs by escaping
any '/', '_' and ':' and similarly problematic characters.
Similar to urllib.quote, except that the quoting is slightly different so
that it doesn't get automatically unquoted by the Web browser.
if not isinstance(s, six.string_types):
return s
res = list(s)
for i in range(len(res)):
c = res[i]
if c in """:/_#?;@&=+$,"<>%\\""":
res[i] = '_%02X' % ord(c)
return ''.join(res)
def unquote(s):
Undo the effects of quote(). Based heavily on urllib.unquote().
mychr = chr
myatoi = int
list = s.split('_')
res = [list[0]]
myappend = res.append
del list[0]
for item in list:
if item[1:2]:
myappend(mychr(myatoi(item[:2], 16)) + item[2:])
except ValueError:
myappend('_' + item)
myappend('_' + item)
return "".join(res)
def flatten_fieldsets(fieldsets):
"""Returns a list of field names from an admin fieldsets structure."""
field_names = []
for name, opts in fieldsets:
for field in opts['fields']:
# type checking feels dirty, but it seems like the best way here
if type(field) == tuple:
return field_names
def get_deleted_objects(objs, opts, user, admin_site, using):
Find all objects related to ``objs`` that should also be deleted. ``objs``
must be a homogenous iterable of objects (e.g. a QuerySet).
Returns a nested list of strings suitable for display in the
template with the ``unordered_list`` filter.
collector = NestedObjects(using=using)
perms_needed = set()
def format_callback(obj):
has_admin = obj.__class__ in admin_site._registry
opts = obj._meta
if has_admin:
admin_url = reverse('%s:%s_%s_change'
% (,
None, (quote(obj._get_pk_val()),))
p = '%s.%s' % (opts.app_label,
if not user.has_perm(p):
# Display a link to the admin page.
return format_html('{0}: <a href="{1}">{2}</a>',
# Don't display link to edit, because it either has no
# admin or is edited inline.
return '%s: %s' % (capfirst(opts.verbose_name),
to_delete = collector.nested(format_callback)
protected = [format_callback(obj) for obj in collector.protected]
return to_delete, perms_needed, protected
class NestedObjects(Collector):
def __init__(self, *args, **kwargs):
super(NestedObjects, self).__init__(*args, **kwargs)
self.edges = {} # {from_instance: [to_instances]}
self.protected = set()
def add_edge(self, source, target):
self.edges.setdefault(source, []).append(target)
def collect(self, objs, source_attr=None, **kwargs):
for obj in objs:
if source_attr:
self.add_edge(getattr(obj, source_attr), obj)
self.add_edge(None, obj)
return super(NestedObjects, self).collect(objs, source_attr=source_attr, **kwargs)
except models.ProtectedError as e:
def related_objects(self, related, objs):
qs = super(NestedObjects, self).related_objects(related, objs)
return qs.select_related(
def _nested(self, obj, seen, format_callback):
if obj in seen:
return []
children = []
for child in self.edges.get(obj, ()):
children.extend(self._nested(child, seen, format_callback))
if format_callback:
ret = [format_callback(obj)]
ret = [obj]
if children:
return ret
def nested(self, format_callback=None):
Return the graph as a nested list.
seen = set()
roots = []
for root in self.edges.get(None, ()):
roots.extend(self._nested(root, seen, format_callback))
return roots
def model_format_dict(obj):
Return a `dict` with keys 'verbose_name' and 'verbose_name_plural',
typically for use with string formatting.
`obj` may be a `Model` instance, `Model` subclass, or `QuerySet` instance.
if isinstance(obj, (models.Model, models.base.ModelBase)):
opts = obj._meta
elif isinstance(obj, models.query.QuerySet):
opts = obj.model._meta
opts = obj
return {
'verbose_name': force_text(opts.verbose_name),
'verbose_name_plural': force_text(opts.verbose_name_plural)
def model_ngettext(obj, n=None):
Return the appropriate `verbose_name` or `verbose_name_plural` value for
`obj` depending on the count `n`.
`obj` may be a `Model` instance, `Model` subclass, or `QuerySet` instance.
If `obj` is a `QuerySet` instance, `n` is optional and the length of the
`QuerySet` is used.
if isinstance(obj, models.query.QuerySet):
if n is None:
n = obj.count()
obj = obj.model
d = model_format_dict(obj)
singular, plural = d["verbose_name"], d["verbose_name_plural"]
return ungettext(singular, plural, n or 0)
def lookup_field(name, obj, model_admin=None):
opts = obj._meta
f = opts.get_field(name)
except models.FieldDoesNotExist:
# For non-field values, the value is either a method, property or
# returned via a callable.
if callable(name):
attr = name
value = attr(obj)
elif (model_admin is not None and hasattr(model_admin, name) and
not name == '__str__' and not name == '__unicode__'):
attr = getattr(model_admin, name)
value = attr(obj)
attr = getattr(obj, name)
if callable(attr):
value = attr()
value = attr
f = None
attr = None
value = getattr(obj, name)
return f, attr, value
def label_for_field(name, model, model_admin=None, return_attr=False):
Returns a sensible label for a field name. The name can be a callable or the
name of an object attributes, as well as a genuine fields. If return_attr is
True, the resolved attribute (which could be a callable) is also returned.
This will be None if (and only if) the name refers to a field.
attr = None
field = model._meta.get_field_by_name(name)[0]
if isinstance(field, RelatedObject):
label = field.opts.verbose_name
label = field.verbose_name
except models.FieldDoesNotExist:
if name == "__unicode__":
label = force_text(model._meta.verbose_name)
attr = six.text_type
elif name == "__str__":
label = force_str(model._meta.verbose_name)
attr = bytes
if callable(name):
attr = name
elif model_admin is not None and hasattr(model_admin, name):
attr = getattr(model_admin, name)
elif hasattr(model, name):
attr = getattr(model, name)
message = "Unable to lookup '%s' on %s" % (name, model._meta.object_name)
if model_admin:
message += " or %s" % (model_admin.__class__.__name__,)
raise AttributeError(message)
if hasattr(attr, "short_description"):
label = attr.short_description
elif callable(attr):
if attr.__name__ == "<lambda>":
label = "--"
label = pretty_name(attr.__name__)
label = pretty_name(name)
if return_attr:
return (label, attr)
return label
def help_text_for_field(name, model):
help_text = model._meta.get_field_by_name(name)[0].help_text
except models.FieldDoesNotExist:
help_text = ""
return smart_text(help_text)
def display_for_field(value, field):
from django.contrib.admin.templatetags.admin_list import _boolean_icon
from django.contrib.admin.views.main import EMPTY_CHANGELIST_VALUE
if field.flatchoices:
return dict(field.flatchoices).get(value, EMPTY_CHANGELIST_VALUE)
# NullBooleanField needs special-case null-handling, so it comes
# before the general null test.
elif isinstance(field, models.BooleanField) or isinstance(field, models.NullBooleanField):
return _boolean_icon(value)
elif value is None:
elif isinstance(field, models.DateTimeField):
return formats.localize(timezone.template_localtime(value))
elif isinstance(field, (models.DateField, models.TimeField)):
return formats.localize(value)
elif isinstance(field, models.DecimalField):
return formats.number_format(value, field.decimal_places)
elif isinstance(field, models.FloatField):
return formats.number_format(value)
return smart_text(value)
def display_for_value(value, boolean=False):
from django.contrib.admin.templatetags.admin_list import _boolean_icon
from django.contrib.admin.views.main import EMPTY_CHANGELIST_VALUE
if boolean:
return _boolean_icon(value)
elif value is None:
elif isinstance(value, datetime.datetime):
return formats.localize(timezone.template_localtime(value))
elif isinstance(value, (, datetime.time)):
return formats.localize(value)
elif isinstance(value, six.integer_types + (decimal.Decimal, float)):
return formats.number_format(value)
return smart_text(value)
class NotRelationField(Exception):
def get_model_from_relation(field):
if isinstance(field, models.related.RelatedObject):
return field.model
elif getattr(field, 'rel'): # or isinstance?
raise NotRelationField
def reverse_field_path(model, path):
""" Create a reversed field path.
E.g. Given (Order, "user__groups"),
return (Group, "user__order").
Final field must be a related model, not a data field.
reversed_path = []
parent = model
pieces = path.split(LOOKUP_SEP)
for piece in pieces:
field, model, direct, m2m = parent._meta.get_field_by_name(piece)
# skip trailing data field if extant:
if len(reversed_path) == len(pieces)-1: # final iteration
except NotRelationField:
if direct:
related_name = field.related_query_name()
parent =
related_name =
parent = field.model
reversed_path.insert(0, related_name)
return (parent, LOOKUP_SEP.join(reversed_path))
def get_fields_from_path(model, path):
""" Return list of Fields given path relative to model.
e.g. (ModelX, "user__groups__name") -> [
<django.db.models.fields.related.ForeignKey object at 0x...>,
<django.db.models.fields.related.ManyToManyField object at 0x...>,
<django.db.models.fields.CharField object at 0x...>,
pieces = path.split(LOOKUP_SEP)
fields = []
for piece in pieces:
if fields:
parent = get_model_from_relation(fields[-1])
parent = model
return fields
def remove_trailing_data_field(fields):
""" Discard trailing non-relation field if extant. """
except NotRelationField:
fields = fields[:-1]
return fields
def get_limit_choices_to_from_path(model, path):
""" Return Q object for limiting choices if applicable.
If final model in path is linked via a ForeignKey or ManyToManyField which
has a `limit_choices_to` attribute, return it as a Q object.
fields = get_fields_from_path(model, path)
fields = remove_trailing_data_field(fields)
limit_choices_to = (
fields and hasattr(fields[-1], 'rel') and
getattr(fields[-1].rel, 'limit_choices_to', None))
if not limit_choices_to:
return models.Q() # empty Q
elif isinstance(limit_choices_to, models.Q):
return limit_choices_to # already a Q
return models.Q(**limit_choices_to) # convert dict to Q
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