Mongoengine supportΒΆ

Flask-FS provides a thin mongoengine integration as field classes.

Both FileField and ImageField provides a common interface:

images = fs.Storage('images', fs.IMAGES,
                    upload_to=lambda o: 'prefix',
                    basename=lambda o: 'basename')

class MyDoc(Document):
    file = FileField(fs=files)

doc = MyDoc()

# Test file presence
print(bool(doc.file))  # False
# Get filename
print(doc.file.filename)  # None
# Get file URL
print(doc.file.url)  # None
# Print file URL
print(str(doc.file))  # '''xxx'), 'test.file')

print(bool(doc.file))  # True
print(doc.file.filename)  # 'test.file'
print(doc.file.url)  # ''
print(str(doc.file))  # ''

# Override Werkzeug Filestorage filename with basename
f = FileStorage(io.Bytes(b'xxx'), 'test.file')
print(doc.file.filename)  # 'basename.file'

The ImageField provides some extra features.

On declaration:

  • an optionnal max_size attribute allows to limit image size
  • an optionnal thumbnails list of thumbnail sizes to be generated
  • an optionnal optimize booleanoverriding the FS_IMAGES_OPTIMIZE setting by field.

On instance:

  • the original property gives the unmodified image filename
  • the best_url(size) method match a thumbnail URL given a size
  • the thumbnail(size) method get a thumbnail filename given a registered size
  • the save method accept an optionnal bbox kwarg for to crop the thumbnails
  • the rerender method allows to force a new image rendering (taking in account new parameters)
  • the instance is callable as shortcut for best_url()
images = fs.Storage('images', fs.IMAGES)
files = fs.Storage('files', fs.ALL)

class MyDoc(Document):
    image = ImageField(fs=images,
                       thumbnails=[100, 32])

doc = MyDoc()

with open(some_image, 'rb') as f:, 'test.png')

print(doc.image.filename)  # 'test.png'
print(doc.image.original)  # 'test-original.png'
print(doc.image.thumbnail(100))  # 'test-100.png'
print(doc.image.thumbnail(32))  # 'test-32.png'

# Guess best image url for a given size
assert doc.image.best_url().endswith(doc.image.filename)
assert doc.image.best_url(200).endswith(doc.image.filename)
assert doc.image.best_url(150).endswith(doc.image.filename)
assert doc.image.best_url(100).endswith(doc.image.thumbnail(100))
assert doc.image.best_url(90).endswith(doc.image.thumbnail(100))
assert doc.image.best_url(30).endswith(doc.image.thumbnail(32))

# Call as shortcut for best_url()
assert doc.image().endswith(doc.image.filename)
assert doc.image(200).endswith(doc.image.filename)
assert doc.image(150).endswith(doc.image.filename)
assert doc.image(100).endswith(doc.image.thumbnail(100))

# Save an optionnal bbox for thumbnails cropping
bbox = (10, 10, 100, 100)
with open(some_image, 'rb') as f:, 'test.png', bbox=bbox)