我正在使用Flask-Admin并且非常满意。但是，Flask-Admin中的示例仅提供将图像上载到静态文件夹。是否可以使用Flask-Admin直接将其上传到S3？感谢。
此致 亚历
答案 0 :(得分：3)
这是代码但不干净。
import os
import os.path as op
import cStringIO
import logging
import config
from flask import url_for
from werkzeug import secure_filename
from werkzeug.datastructures import FileStorage
import boto
from boto.s3.key import Key
from wtforms import ValidationError, fields
from wtforms.widgets import HTMLString, html_params
from flask.ext.admin.babel import gettext
from flask.ext.admin._compat import string_types, urljoin
from flask.ext.admin.form.upload import ImageUploadField
try:
from PIL import Image, ImageOps
except ImportError:
Image = None
ImageOps = None
__all__ = ['FileUploadInput', 'FileUploadField',
'ImageUploadInput', 'ImageUploadField',
'namegen_filename', 'thumbgen_filename']
class ImageUploadInput(object):
"""
Renders a image input chooser field.
You can customize `empty_template` and `data_template` members to customize
look and feel.
"""
empty_template = ('<input %(file)s>')
data_template = ('<div class="image-thumbnail">'
' <img %(image)s>'
' <input type="checkbox" name="%(marker)s">Delete</input>'
'</div>'
'<input %(file)s>')
def __call__(self, field, **kwargs):
kwargs.setdefault('id', field.id)
kwargs.setdefault('name', field.name)
args = {
'file': html_params(type='file',
**kwargs),
'marker': '_%s-delete' % field.name
}
if field.data and isinstance(field.data, string_types):
url = self.get_url(field)
args['image'] = html_params(src=url)
template = self.data_template
else:
template = self.empty_template
return HTMLString(template % args)
def get_url(self, field):
if field.thumbnail_size:
filename = field.thumbnail_fn(field.data)
else:
filename = field.data
if field.url_relative_path:
filename = urljoin(field.url_relative_path, filename)
return field.data
#return url_for(field.endpoint, filename=field.data)
class s3ImageUploadField(ImageUploadField):
"""
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.
"""
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 Exception('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):
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._resize(self.image, (500, 500))
#image = self.image
self._save_image(image, filename, format)
else:
data.seek(0)
data.save(path)
savedUrl=self._save_image(self.image, filename, format)
self._save_thumbnail(data, filename, format)
return savedUrl
def _save_thumbnail(self, data, filename, format):
if self.image and self.thumbnail_size:
path = self._get_path(self.thumbnail_fn(filename))
savedUrl=self._save_image(self._resize(self.image, self.thumbnail_size),
thumbgen_filename(filename),
format)
return savedUrl
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')
conn =boto.connect_s3( config.AWS_KEY, config.AWS_SECRET,)
bucket = conn.get_bucket("vipbutton")
k = Key(bucket)
k.key= path
tempFile = cStringIO.StringIO()
image.save(tempFile,format)
#image.seek(0)
#tempFile.seek(0)
#k.set_contents_from_string('This is a test of S3')
k.set_contents_from_string(tempFile.getvalue())
k.set_acl('public-read')
#k.set_contents_from_file(tempFile.getValue())
#with open(path, 'wb') as fp:
# image.save(fp, format)
return k.generate_url(expires_in=0, query_auth=False)
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)
答案 1 :(得分：3)
感谢您的示例代码，Alex Chan。我也需要此功能，因此我决定根据您的代码和其他各种代码段编写更完整的S3FileUploadField和S3ImageUploadField类。
您可以在以下网址找到我的代码：
https://github.com/Jaza/flask-admin-s3-upload
也在pypi上，所以你可以安装：
pip install flask-admin-s3-upload
我已经在自述文件中记录了一个基本用法示例（可以在github项目页面上看到它）。希望这对于需要在flask-admin中上传S3文件的任何其他人都有帮助。
答案 2 :(得分：2)
我终于解决了但是继承了ImageUploadField并使用boto上传图像。 ：）