django1/django/db/models/fields/files.py

316 lines
13 KiB
Python

import datetime
import os
from django.conf import settings
from django.db.models.fields import Field
from django.core.files.base import File, ContentFile
from django.core.files.storage import default_storage
from django.core.files.images import ImageFile, get_image_dimensions
from django.core.files.uploadedfile import UploadedFile
from django.utils.functional import curry
from django.db.models import signals
from django.utils.encoding import force_unicode, smart_str
from django.utils.translation import ugettext_lazy, ugettext as _
from django import oldforms
from django import forms
from django.core import validators
from django.db.models.loading import cache
class FieldFile(File):
def __init__(self, instance, field, name):
self.instance = instance
self.field = field
self.storage = field.storage
self._name = name or u''
self._closed = False
def __eq__(self, other):
# Older code may be expecting FileField values to be simple strings.
# By overriding the == operator, it can remain backwards compatibility.
if hasattr(other, 'name'):
return self.name == other.name
return self.name == other
# The standard File contains most of the necessary properties, but
# FieldFiles can be instantiated without a name, so that needs to
# be checked for here.
def _require_file(self):
if not self:
raise ValueError("The '%s' attribute has no file associated with it." % self.field.name)
def _get_file(self):
self._require_file()
if not hasattr(self, '_file'):
self._file = self.storage.open(self.name, 'rb')
return self._file
file = property(_get_file)
def _get_path(self):
self._require_file()
return self.storage.path(self.name)
path = property(_get_path)
def _get_url(self):
self._require_file()
return self.storage.url(self.name)
url = property(_get_url)
def open(self, mode='rb'):
self._require_file()
return super(FieldFile, self).open(mode)
# open() doesn't alter the file's contents, but it does reset the pointer
open.alters_data = True
# In addition to the standard File API, FieldFiles have extra methods
# to further manipulate the underlying file, as well as update the
# associated model instance.
def save(self, name, content, save=True):
name = self.field.generate_filename(self.instance, name)
self._name = self.storage.save(name, content)
setattr(self.instance, self.field.name, self.name)
# Update the filesize cache
self._size = len(content)
# Save the object because it has changed, unless save is False
if save:
self.instance.save()
save.alters_data = True
def delete(self, save=True):
self.close()
self.storage.delete(self.name)
self._name = None
setattr(self.instance, self.field.name, self.name)
# Delete the filesize cache
if hasattr(self, '_size'):
del self._size
if save:
self.instance.save()
delete.alters_data = True
def __getstate__(self):
# FieldFile needs access to its associated model field and an instance
# it's attached to in order to work properly, but the only necessary
# data to be pickled is the file's name itself. Everything else will
# be restored later, by FileDescriptor below.
return {'_name': self.name, '_closed': False}
class FileDescriptor(object):
def __init__(self, field):
self.field = field
def __get__(self, instance=None, owner=None):
if instance is None:
raise AttributeError, "%s can only be accessed from %s instances." % (self.field.name(self.owner.__name__))
file = instance.__dict__[self.field.name]
if not isinstance(file, FieldFile):
# Create a new instance of FieldFile, based on a given file name
instance.__dict__[self.field.name] = self.field.attr_class(instance, self.field, file)
elif not hasattr(file, 'field'):
# The FieldFile was pickled, so some attributes need to be reset.
file.instance = instance
file.field = self.field
file.storage = self.field.storage
return instance.__dict__[self.field.name]
def __set__(self, instance, value):
instance.__dict__[self.field.name] = value
class FileField(Field):
attr_class = FieldFile
def __init__(self, verbose_name=None, name=None, upload_to='', storage=None, **kwargs):
for arg in ('core', 'primary_key', 'unique'):
if arg in kwargs:
raise TypeError("'%s' is not a valid argument for %s." % (arg, self.__class__))
self.storage = storage or default_storage
self.upload_to = upload_to
if callable(upload_to):
self.generate_filename = upload_to
kwargs['max_length'] = kwargs.get('max_length', 100)
super(FileField, self).__init__(verbose_name, name, **kwargs)
def get_internal_type(self):
return "FileField"
def get_db_prep_lookup(self, lookup_type, value):
if hasattr(value, 'name'):
value = value.name
return super(FileField, self).get_db_prep_lookup(lookup_type, value)
def get_db_prep_value(self, value):
"Returns field's value prepared for saving into a database."
# Need to convert File objects provided via a form to unicode for database insertion
if value is None:
return None
return unicode(value)
def get_manipulator_fields(self, opts, manipulator, change, name_prefix='', rel=False, follow=True):
field_list = Field.get_manipulator_fields(self, opts, manipulator, change, name_prefix, rel, follow)
if not self.blank:
if rel:
# This validator makes sure FileFields work in a related context.
class RequiredFileField(object):
def __init__(self, other_field_names, other_file_field_name):
self.other_field_names = other_field_names
self.other_file_field_name = other_file_field_name
self.always_test = True
def __call__(self, field_data, all_data):
if not all_data.get(self.other_file_field_name, False):
c = validators.RequiredIfOtherFieldsGiven(self.other_field_names, ugettext_lazy("This field is required."))
c(field_data, all_data)
# First, get the core fields, if any.
core_field_names = []
for f in opts.fields:
if f.core and f != self:
core_field_names.extend(f.get_manipulator_field_names(name_prefix))
# Now, if there are any, add the validator to this FormField.
if core_field_names:
field_list[0].validator_list.append(RequiredFileField(core_field_names, field_list[1].field_name))
else:
v = validators.RequiredIfOtherFieldNotGiven(field_list[1].field_name, ugettext_lazy("This field is required."))
v.always_test = True
field_list[0].validator_list.append(v)
field_list[0].is_required = field_list[1].is_required = False
# If the raw path is passed in, validate it's under the MEDIA_ROOT.
def isWithinMediaRoot(field_data, all_data):
f = os.path.abspath(os.path.join(settings.MEDIA_ROOT, field_data))
if not f.startswith(os.path.abspath(os.path.normpath(settings.MEDIA_ROOT))):
raise validators.ValidationError(_("Enter a valid filename."))
field_list[1].validator_list.append(isWithinMediaRoot)
return field_list
def contribute_to_class(self, cls, name):
super(FileField, self).contribute_to_class(cls, name)
setattr(cls, self.name, FileDescriptor(self))
setattr(cls, 'get_%s_filename' % self.name, curry(cls._get_FIELD_filename, field=self))
setattr(cls, 'get_%s_url' % self.name, curry(cls._get_FIELD_url, field=self))
setattr(cls, 'get_%s_size' % self.name, curry(cls._get_FIELD_size, field=self))
setattr(cls, 'save_%s_file' % self.name, lambda instance, name, content, save=True: instance._save_FIELD_file(self, name, content, save))
signals.post_delete.connect(self.delete_file, sender=cls)
def delete_file(self, instance, sender, **kwargs):
file = getattr(instance, self.attname)
# If no other object of this type references the file,
# and it's not the default value for future objects,
# delete it from the backend.
if file and file.name != self.default and \
not sender._default_manager.filter(**{self.name: file.name}):
file.delete(save=False)
elif file:
# Otherwise, just close the file, so it doesn't tie up resources.
file.close()
def get_manipulator_field_objs(self):
return [oldforms.FileUploadField, oldforms.HiddenField]
def get_manipulator_field_names(self, name_prefix):
return [name_prefix + self.name + '_file', name_prefix + self.name]
def save_file(self, new_data, new_object, original_object, change, rel, save=True):
upload_field_name = self.get_manipulator_field_names('')[0]
if new_data.get(upload_field_name, False):
if rel:
file = new_data[upload_field_name][0]
else:
file = new_data[upload_field_name]
# Backwards-compatible support for files-as-dictionaries.
# We don't need to raise a warning because the storage backend will
# do so for us.
try:
filename = file.name
except AttributeError:
filename = file['filename']
filename = self.get_filename(filename)
getattr(new_object, self.attname).save(filename, file, save)
def get_directory_name(self):
return os.path.normpath(force_unicode(datetime.datetime.now().strftime(smart_str(self.upload_to))))
def get_filename(self, filename):
return os.path.normpath(self.storage.get_valid_name(os.path.basename(filename)))
def generate_filename(self, instance, filename):
return os.path.join(self.get_directory_name(), self.get_filename(filename))
def save_form_data(self, instance, data):
if data and isinstance(data, UploadedFile):
getattr(instance, self.name).save(data.name, data, save=False)
def formfield(self, **kwargs):
defaults = {'form_class': forms.FileField}
# If a file has been provided previously, then the form doesn't require
# that a new file is provided this time.
# The code to mark the form field as not required is used by
# form_for_instance, but can probably be removed once form_for_instance
# is gone. ModelForm uses a different method to check for an existing file.
if 'initial' in kwargs:
defaults['required'] = False
defaults.update(kwargs)
return super(FileField, self).formfield(**defaults)
class ImageFieldFile(ImageFile, FieldFile):
def save(self, name, content, save=True):
if not hasattr(content, 'read'):
import warnings
warnings.warn(
message = "Representing files as strings is deprecated." \
"Use django.core.files.base.ContentFile instead.",
category = DeprecationWarning,
stacklevel = 2
)
content = ContentFile(content)
# Repopulate the image dimension cache.
self._dimensions_cache = get_image_dimensions(content)
# Update width/height fields, if needed
if self.field.width_field:
setattr(self.instance, self.field.width_field, self.width)
if self.field.height_field:
setattr(self.instance, self.field.height_field, self.height)
super(ImageFieldFile, self).save(name, content, save)
def delete(self, save=True):
# Clear the image dimensions cache
if hasattr(self, '_dimensions_cache'):
del self._dimensions_cache
super(ImageFieldFile, self).delete(save)
class ImageField(FileField):
attr_class = ImageFieldFile
def __init__(self, verbose_name=None, name=None, width_field=None, height_field=None, **kwargs):
self.width_field, self.height_field = width_field, height_field
FileField.__init__(self, verbose_name, name, **kwargs)
def get_manipulator_field_objs(self):
return [oldforms.ImageUploadField, oldforms.HiddenField]
def contribute_to_class(self, cls, name):
super(ImageField, self).contribute_to_class(cls, name)
# Add get_BLAH_width and get_BLAH_height methods, but only if the
# image field doesn't have width and height cache fields.
if not self.width_field:
setattr(cls, 'get_%s_width' % self.name, curry(cls._get_FIELD_width, field=self))
if not self.height_field:
setattr(cls, 'get_%s_height' % self.name, curry(cls._get_FIELD_height, field=self))
def formfield(self, **kwargs):
defaults = {'form_class': forms.ImageField}
defaults.update(kwargs)
return super(ImageField, self).formfield(**defaults)