import os
import os.path as op
from werkzeug import secure_filename
from werkzeug.datastructures import FileStorage
from wtforms import ValidationError, fields
from wtforms.widgets import HTMLString, html_params
try:
from wtforms.fields.core import _unset_value as unset_value
except ImportError:
from wtforms.utils import unset_value
from flask.ext.admin.babel import gettext
from flask.ext.admin.helpers import get_url
from flask.ext.admin._compat import string_types, urljoin
try:
from PIL import Image, ImageOps
except ImportError:
Image = None
ImageOps = None
__all__ = ['FileUploadInput', 'FileUploadField',
'ImageUploadInput', 'ImageUploadField',
'namegen_filename', 'thumbgen_filename']
# Widgets
[docs]class FileUploadField(fields.StringField):
"""
Customizable file-upload field.
Saves file to configured path, handles updates and deletions. Inherits from `StringField`,
resulting filename will be stored as string.
"""
widget = FileUploadInput()
[docs] def __init__(self, label=None, validators=None,
base_path=None, relative_path=None,
namegen=None, allowed_extensions=None,
permission=0o666,
**kwargs):
"""
Constructor.
:param label:
Display label
:param validators:
Validators
:param base_path:
Absolute path to the directory which will store files
:param relative_path:
Relative path from the directory. Will be prepended to the file name for uploaded files.
Flask-Admin uses `urlparse.urljoin` to generate resulting filename, so make sure you have
trailing slash.
:param namegen:
Function that will generate filename from the model and uploaded file object.
Please note, that model is "dirty" model object, before it was committed to database.
For example::
import os.path as op
def prefix_name(obj, file_data):
parts = op.splitext(file_data.filename)
return secure_filename('file-%s%s' % parts)
class MyForm(BaseForm):
upload = FileUploadField('File', namegen=prefix_name)
:param allowed_extensions:
List of allowed extensions. If not provided, will allow any file.
"""
self.base_path = base_path
self.relative_path = relative_path
self.namegen = namegen or namegen_filename
self.allowed_extensions = allowed_extensions
self.permission = permission
self._should_delete = False
super(FileUploadField, self).__init__(label, validators, **kwargs)
def is_file_allowed(self, filename):
"""
Check if file extension is allowed.
:param filename:
File name to check
"""
if not self.allowed_extensions:
return True
return ('.' in filename and
filename.rsplit('.', 1)[1].lower() in
map(lambda x: x.lower(), self.allowed_extensions))
def pre_validate(self, form):
if (self.data
and self.data.filename
and isinstance(self.data, FileStorage)
and not self.is_file_allowed(self.data.filename)):
raise ValidationError(gettext('Invalid file extension'))
def process(self, formdata, data=unset_value):
if formdata:
marker = '_%s-delete' % self.name
if marker in formdata:
self._should_delete = True
return super(FileUploadField, self).process(formdata, data)
def populate_obj(self, obj, name):
field = getattr(obj, name, None)
if field:
# If field should be deleted, clean it up
if self._should_delete:
self._delete_file(field)
setattr(obj, name, None)
return
if self.data and self.data.filename and isinstance(self.data, FileStorage):
if field:
self._delete_file(field)
filename = self.generate_name(obj, self.data)
filename = self._save_file(self.data, filename)
# update filename of FileStorage to our validated name
self.data.filename = filename
setattr(obj, name, filename)
def generate_name(self, obj, file_data):
filename = self.namegen(obj, file_data)
if not self.relative_path:
return filename
return urljoin(self.relative_path, filename)
def _get_path(self, filename):
if not self.base_path:
raise ValueError('FileUploadField field requires base_path to be set.')
if callable(self.base_path):
return op.join(self.base_path(), filename)
return op.join(self.base_path, filename)
def _delete_file(self, filename):
path = self._get_path(filename)
if op.exists(path):
os.remove(path)
def _save_file(self, data, filename):
path = self._get_path(filename)
if not op.exists(op.dirname(path)):
os.makedirs(os.path.dirname(path), self.permission | 0o111)
data.save(path)
return filename
[docs]class ImageUploadField(FileUploadField):
"""
Image upload field.
Does image validation, thumbnail generation, updating and deleting images.
Requires PIL (or Pillow) to be installed.
"""
widget = ImageUploadInput()
keep_image_formats = ('PNG',)
"""
If field detects that uploaded image is not in this list, it will save image
as PNG.
"""
[docs] def __init__(self, label=None, validators=None,
base_path=None, relative_path=None,
namegen=None, allowed_extensions=None,
max_size=None,
thumbgen=None, thumbnail_size=None,
permission=0o666,
url_relative_path=None, endpoint='static',
**kwargs):
"""
Constructor.
:param label:
Display label
:param validators:
Validators
:param base_path:
Absolute path to the directory which will store files
:param relative_path:
Relative path from the directory. Will be prepended to the file name for uploaded files.
Flask-Admin uses `urlparse.urljoin` to generate resulting filename, so make sure you have
trailing slash.
:param namegen:
Function that will generate filename from the model and uploaded file object.
Please note, that model is "dirty" model object, before it was committed to database.
For example::
import os.path as op
def prefix_name(obj, file_data):
parts = op.splitext(file_data.filename)
return secure_filename('file-%s%s' % parts)
class MyForm(BaseForm):
upload = FileUploadField('File', namegen=prefix_name)
:param allowed_extensions:
List of allowed extensions. If not provided, will allow any file.
:param max_size:
Tuple of (width, height, force) or None. If provided, Flask-Admin will
resize image to the desired size.
:param thumbgen:
Thumbnail filename generation function. All thumbnails will be saved as JPEG files,
so there's no need to keep original file extension.
For example::
import os.path as op
def thumb_name(filename):
name, _ = op.splitext(filename)
return secure_filename('%s-thumb.jpg' % name)
class MyForm(BaseForm):
upload = ImageUploadField('File', thumbgen=prefix_name)
:param thumbnail_size:
Tuple or (width, height, force) values. If not provided, thumbnail won't be created.
Width and height is in pixels. If `force` is set to `True`, will try to fit image into dimensions and
keep aspect ratio, otherwise will just resize to target size.
:param url_relative_path:
Relative path from the root of the static directory URL. Only gets used when generating
preview image URLs.
For example, your model might store just file names (`relative_path` set to `None`), but
`base_path` is pointing to subdirectory.
:param endpoint:
Static endpoint for images. Used by widget to display previews. Defaults to 'static'.
"""
# Check if PIL is installed
if Image is None:
raise ImportError('PIL library was not found')
self.max_size = max_size
self.thumbnail_fn = thumbgen or thumbgen_filename
self.thumbnail_size = thumbnail_size
self.endpoint = endpoint
self.image = None
self.url_relative_path = url_relative_path
if not allowed_extensions:
allowed_extensions = ('gif', 'jpg', 'jpeg', 'png', 'tiff')
super(ImageUploadField, self).__init__(label, validators,
base_path=base_path,
relative_path=relative_path,
namegen=namegen,
allowed_extensions=allowed_extensions,
permission=permission,
**kwargs)
def pre_validate(self, form):
super(ImageUploadField, self).pre_validate(form)
if (self.data and
isinstance(self.data, FileStorage) and
self.data.filename):
try:
self.image = Image.open(self.data)
except Exception as e:
raise ValidationError('Invalid image: %s' % e)
# Deletion
def _delete_file(self, filename):
super(ImageUploadField, self)._delete_file(filename)
self._delete_thumbnail(filename)
def _delete_thumbnail(self, filename):
path = self._get_path(self.thumbnail_fn(filename))
if op.exists(path):
os.remove(path)
# Saving
def _save_file(self, data, filename):
path = self._get_path(filename)
if not op.exists(op.dirname(path)):
os.makedirs(os.path.dirname(path), self.permission)
# Figure out format
filename, format = self._get_save_format(filename, self.image)
if self.image and (self.image.format != format or self.max_size):
if self.max_size:
image = self._resize(self.image, self.max_size)
else:
image = self.image
self._save_image(image, self._get_path(filename), format)
else:
data.seek(0)
data.save( self._get_path(filename) )
self._save_thumbnail(data, filename, format)
return filename
def _save_thumbnail(self, data, filename, format):
if self.image and self.thumbnail_size:
path = self._get_path(self.thumbnail_fn(filename))
self._save_image(self._resize(self.image, self.thumbnail_size),
path,
format)
def _resize(self, image, size):
(width, height, force) = size
if image.size[0] > width or image.size[1] > height:
if force:
return ImageOps.fit(self.image, (width, height), Image.ANTIALIAS)
else:
thumb = self.image.copy()
thumb.thumbnail((width, height), Image.ANTIALIAS)
return thumb
return image
def _save_image(self, image, path, format='JPEG'):
if image.mode not in ('RGB', 'RGBA'):
image = image.convert('RGBA')
with open(path, 'wb') as fp:
image.save(fp, format)
def _get_save_format(self, filename, image):
if image.format not in self.keep_image_formats:
name, ext = op.splitext(filename)
filename = '%s.jpg' % name
return filename, 'JPEG'
return filename, image.format
# Helpers
def namegen_filename(obj, file_data):
"""
Generate secure filename for uploaded file.
"""
return secure_filename(file_data.filename)
def thumbgen_filename(filename):
"""
Generate thumbnail name from filename.
"""
name, ext = op.splitext(filename)
return '%s_thumb%s' % (name, ext)
