# -*- coding: utf-8 -*-
#
# jQuery File Upload Plugin GAE Python Example
# https://github.com/blueimp/jQuery-File-Upload
#
# Copyright 2011, Sebastian Tschan
# https://blueimp.net
#
# Licensed under the MIT license:
# https://opensource.org/licenses/MIT
#
from google.appengine.api import memcache, images
import json
import os
import re
import urllib
import webapp2
DEBUG=os.environ.get('SERVER_SOFTWARE', '').startswith('Dev')
WEBSITE = 'https://blueimp.github.io/jQuery-File-Upload/'
MIN_FILE_SIZE = 1 # bytes
# Max file size is memcache limit (1MB) minus key size minus overhead:
MAX_FILE_SIZE = 999000 # bytes
IMAGE_TYPES = re.compile('image/(gif|p?jpeg|(x-)?png)')
ACCEPT_FILE_TYPES = IMAGE_TYPES
THUMB_MAX_WIDTH = 80
THUMB_MAX_HEIGHT = 80
THUMB_SUFFIX = '.'+str(THUMB_MAX_WIDTH)+'x'+str(THUMB_MAX_HEIGHT)+'.png'
EXPIRATION_TIME = 300 # seconds
# If set to None, only allow redirects to the referer protocol+host.
# Set to a regexp for custom pattern matching against the redirect value:
REDIRECT_ALLOW_TARGET = None
class CORSHandler(webapp2.RequestHandler):
def cors(self):
headers = self.response.headers
headers['Access-Control-Allow-Origin'] = '*'
headers['Access-Control-Allow-Methods'] =\
'OPTIONS, HEAD, GET, POST, DELETE'
headers['Access-Control-Allow-Headers'] =\
'Content-Type, Content-Range, Content-Disposition'
def initialize(self, request, response):
super(CORSHandler, self).initialize(request, response)
self.cors()
def json_stringify(self, obj):
return json.dumps(obj, separators=(',', ':'))
def options(self, *args, **kwargs):
pass
class UploadHandler(CORSHandler):
def validate(self, file):
if file['size'] < MIN_FILE_SIZE:
file['error'] = 'File is too small'
elif file['size'] > MAX_FILE_SIZE:
file['error'] = 'File is too big'
elif not ACCEPT_FILE_TYPES.match(file['type']):
file['error'] = 'Filetype not allowed'
else:
return True
return False
def validate_redirect(self, redirect):
if redirect:
if REDIRECT_ALLOW_TARGET:
return REDIRECT_ALLOW_TARGET.match(redirect)
referer = self.request.headers['referer']
if referer:
from urlparse import urlparse
parts = urlparse(referer)
redirect_allow_target = '^' + re.escape(
parts.scheme + '://' + parts.netloc + '/'
)
return re.match(redirect_allow_target, redirect)
return False
def get_file_size(self, file):
file.seek(0, 2) # Seek to the end of the file
size = file.tell() # Get the position of EOF
file.seek(0) # Reset the file position to the beginning
return size
def write_blob(self, data, info):
key = urllib.quote(info['type'].encode('utf-8'), '') +\
'/' + str(hash(data)) +\
'/' + urllib.quote(info['name'].encode('utf-8'), '')
try:
memcache.set(key, data, time=EXPIRATION_TIME)
except: #Failed to add to memcache
return (None, None)
thumbnail_key = None
if IMAGE_TYPES.match(info['type']):
try:
img = images.Image(image_data=data)
img.resize(
width=THUMB_MAX_WIDTH,
height=THUMB_MAX_HEIGHT
)
thumbnail_data = img.execute_transforms()
thumbnail_key = key + THUMB_SUFFIX
memcache.set(
thumbnail_key,
thumbnail_data,
time=EXPIRATION_TIME
)
except: #Failed to resize Image or add to memcache
thumbnail_key = None
return (key, thumbnail_key)
def handle_upload(self):
results = []
for name, fieldStorage in self.request.POST.items():
if type(fieldStorage) is unicode:
continue
result = {}
result['name'] = urllib.unquote(fieldStorage.filename)
result['type'] = fieldStorage.type
result['size'] = self.get_file_size(fieldStorage.file)
if self.validate(result):
key, thumbnail_key = self.write_blob(
fieldStorage.value,
result
)
if key is not None:
result['url'] = self.request.host_url + '/' + key
result['deleteUrl'] = result['url']
result['deleteType'] = 'DELETE'
if thumbnail_key is not None:
result['thumbnailUrl'] = self.request.host_url +\
'/' + thumbnail_key
else:
result['error'] = 'Failed to store uploaded file.'
results.append(result)
return results
def head(self):
pass
def get(self):
self.redirect(WEBSITE)
def post(self):
if (self.request.get('_method') == 'DELETE'):
return self.delete()
result = {'files': self.handle_upload()}
s = self.json_stringify(result)
redirect = self.request.get('redirect')
if self.validate_redirect(redirect):
return self.redirect(str(
redirect.replace('%s', urllib.quote(s, ''), 1)
))
if 'application/json' in self.request.headers.get('Accept'):
self.response.headers['Content-Type'] = 'application/json'
self.response.write(s)
class FileHandler(CORSHandler):
def normalize(self, str):
return urllib.quote(urllib.unquote(str), '')
def get(self, content_type, data_hash, file_name):
content_type = self.normalize(content_type)
file_name = self.normalize(file_name)
key = content_type + '/' + data_hash + '/' + file_name
data = memcache.get(key)
if data is None:
return self.error(404)
# Prevent browsers from MIME-sniffing the content-type:
self.response.headers['X-Content-Type-Options'] = 'nosniff'
content_type = urllib.unquote(content_type)
if not IMAGE_TYPES.match(content_type):
# Force a download dialog for non-image types:
content_type = 'application/octet-stream'
elif file_name.endswith(THUMB_SUFFIX):
content_type = 'image/png'
self.response.headers['Content-Type'] = content_type
# Cache for the expiration time:
self.response.headers['Cache-Control'] = 'public,max-age=%d' \
% EXPIRATION_TIME
self.response.write(data)
def delete(self, content_type, data_hash, file_name):
content_type = self.normalize(content_type)
file_name = self.normalize(file_name)
key = content_type + '/' + data_hash + '/' + file_name
result = {key: memcache.delete(key)}
content_type = urllib.unquote(content_type)
if IMAGE_TYPES.match(content_type):
thumbnail_key = key + THUMB_SUFFIX
result[thumbnail_key] = memcache.delete(thumbnail_key)
if 'application/json' in self.request.headers.get('Accept'):
self.response.headers['Content-Type'] = 'application/json'
s = self.json_stringify(result)
self.response.write(s)
app = webapp2.WSGIApplication(
[
('/', UploadHandler),
('/(.+)/([^/]+)/([^/]+)', FileHandler)
],
debug=DEBUG
)
