mirror of https://github.com/django/django.git
119 lines
3.2 KiB
Python
119 lines
3.2 KiB
Python
"""
|
|
42. Storing files according to a custom storage system
|
|
|
|
``FileField`` and its variations can take a ``storage`` argument to specify how
|
|
and where files should be stored.
|
|
"""
|
|
|
|
import tempfile
|
|
|
|
from django.db import models
|
|
from django.core.files.base import ContentFile
|
|
from django.core.files.storage import FileSystemStorage
|
|
from django.core.cache import cache
|
|
|
|
temp_storage = FileSystemStorage(location=tempfile.gettempdir())
|
|
|
|
# Write out a file to be used as default content
|
|
temp_storage.save('tests/default.txt', ContentFile('default content'))
|
|
|
|
class Storage(models.Model):
|
|
def custom_upload_to(self, filename):
|
|
return 'foo'
|
|
|
|
def random_upload_to(self, filename):
|
|
# This returns a different result each time,
|
|
# to make sure it only gets called once.
|
|
import random
|
|
return '%s/%s' % (random.randint(100, 999), filename)
|
|
|
|
normal = models.FileField(storage=temp_storage, upload_to='tests')
|
|
custom = models.FileField(storage=temp_storage, upload_to=custom_upload_to)
|
|
random = models.FileField(storage=temp_storage, upload_to=random_upload_to)
|
|
default = models.FileField(storage=temp_storage, upload_to='tests', default='tests/default.txt')
|
|
|
|
__test__ = {'API_TESTS':"""
|
|
# An object without a file has limited functionality.
|
|
|
|
>>> obj1 = Storage()
|
|
>>> obj1.normal
|
|
<FieldFile: None>
|
|
>>> obj1.normal.size
|
|
Traceback (most recent call last):
|
|
...
|
|
ValueError: The 'normal' attribute has no file associated with it.
|
|
|
|
# Saving a file enables full functionality.
|
|
|
|
>>> obj1.normal.save('django_test.txt', ContentFile('content'))
|
|
>>> obj1.normal
|
|
<FieldFile: tests/django_test.txt>
|
|
>>> obj1.normal.size
|
|
7
|
|
>>> obj1.normal.read()
|
|
'content'
|
|
|
|
# Files can be read in a little at a time, if necessary.
|
|
|
|
>>> obj1.normal.open()
|
|
>>> obj1.normal.read(3)
|
|
'con'
|
|
>>> obj1.normal.read()
|
|
'tent'
|
|
>>> '-'.join(obj1.normal.chunks(chunk_size=2))
|
|
'co-nt-en-t'
|
|
|
|
# Save another file with the same name.
|
|
|
|
>>> obj2 = Storage()
|
|
>>> obj2.normal.save('django_test.txt', ContentFile('more content'))
|
|
>>> obj2.normal
|
|
<FieldFile: tests/django_test_.txt>
|
|
>>> obj2.normal.size
|
|
12
|
|
|
|
# Push the objects into the cache to make sure they pickle properly
|
|
|
|
>>> cache.set('obj1', obj1)
|
|
>>> cache.set('obj2', obj2)
|
|
>>> cache.get('obj2').normal
|
|
<FieldFile: tests/django_test_.txt>
|
|
|
|
# Deleting an object deletes the file it uses, if there are no other objects
|
|
# still using that file.
|
|
|
|
>>> obj2.delete()
|
|
>>> obj2.normal.save('django_test.txt', ContentFile('more content'))
|
|
>>> obj2.normal
|
|
<FieldFile: tests/django_test_.txt>
|
|
|
|
# Default values allow an object to access a single file.
|
|
|
|
>>> obj3 = Storage.objects.create()
|
|
>>> obj3.default
|
|
<FieldFile: tests/default.txt>
|
|
>>> obj3.default.read()
|
|
'default content'
|
|
|
|
# But it shouldn't be deleted, even if there are no more objects using it.
|
|
|
|
>>> obj3.delete()
|
|
>>> obj3 = Storage()
|
|
>>> obj3.default.read()
|
|
'default content'
|
|
|
|
# Verify the fix for #5655, making sure the directory is only determined once.
|
|
|
|
>>> obj4 = Storage()
|
|
>>> obj4.random.save('random_file', ContentFile('random content'))
|
|
>>> obj4.random
|
|
<FieldFile: .../random_file>
|
|
|
|
# Clean up the temporary files.
|
|
|
|
>>> obj1.normal.delete()
|
|
>>> obj2.normal.delete()
|
|
>>> obj3.default.delete()
|
|
>>> obj4.random.delete()
|
|
"""}
|