I was able to upload large file to server using the below code -
#app.route("/upload", methods=["POST"])
def upload():
with open("/tmp/output_file", "bw") as f:
chunk_size = 4096
while True:
chunk = request.stream.read(chunk_size)
if len(chunk) == 0:
return
f.write(chunk)
But if I use request.form['userId'] or any parameter which is sent as form data in the above code it fails.
As per one of the blog post it says- Flask’s request has a stream, that will have the file data you are uploading. You can read from it treating it as a file-like object. The trick seems to be that you shouldn’t use other request attributes like request.form or request.file because this will materialize the stream into memory/file. Flask by default saves files to disk if they exceed 500Kb, so don’t touch file.
Is there a way where we can send additional parameters like userId along with the file being uploaded in flask?
use headers in requests.
if you want to send user name along with data
headers['username'] = 'name of the user'
r = requests.post(url, data=chunk, headers=headers)
I try to use falcon package in my project. Problem is I didn't find a way to get body data from the HTTP post request.
I used code from example, but req.stream.read() doesn't return JSON as expected.
The code is:
raw_json = req.stream.read()
result.json(raw_json, encoding='utf-8')
resp.body = json.dumps(result_json, encoding='utf-8')
How to get the POST data?
Thanks for any help
in falcon 2, if you work with json type, use req.media
for example:
import falcon
from json import dumps
class Resource(object):
def on_post(self, req, resp, **kwargs):
result = req.media
# do your job
resp.body = dumps(result)
api = falcon.API()
api.add_route('/test', Resource())
Little digging into the problem led to the following linked issue on github. It states that falcon framework at least in its version 0.3 and working with Python 2 didn't parse data 'POSTed' as string if they are aptly escaped. We could use more information on what data you are trying to send over POST request and in what format is that being sent, as in if its being send as simple text, or with Header Information Content-Type:application/json, or if its coming through an HTML form.
While the exact issue is not clear from the question I could still suggest trying to use bounded_stream instead of stream as in:
raw_json = req.bounded_stream.read()
result.json(raw_json, encoding='utf-8')
resp.body = json.dumps(result_json, encoding='utf-8')
for the official documentation suggests use of bounded_stream where uncertain conditions such as Content-Length undefined or 0, or if header information is missing altogether.
bounded_stream is described as the following in the official falcon documentation.
File-like wrapper around stream to normalize certain differences between the native input objects employed by different WSGI servers. In particular, bounded_stream is aware of the expected Content-Length of the body, and will never block on out-of-bounds reads, assuming the client does not stall while transmitting the data to the server.
Falcon receives the HTTP requests data as buffer object as passed by WSGI wrapper which receives the data from client, and its possible it doesn't run proper parsing on top of the data to convert to a more usable data structure for performance reasons.
Big thanks to Ryan (and Prateek Jain) for the answer.
The solution is simply to put app.req_options.auto_parse_form_urlencoded=True. For example:
import falcon
class ThingsResource(object):
def on_post(self, req, resp):
value = req.get_param("value", required=True)
#do something with value
app = falcon.API()
app.req_options.auto_parse_form_urlencoded=True
things = ThingsResource()
app.add_route('/things', things)
The field you're looking for is somewhat confusingly named, but it's req.media:
Returns a deserialized form of the request stream. When called, it will attempt to deserialize the request stream using the Content-Type header as well as the media-type handlers configured via falcon.RequestOptions.
If the request is JSON, req.media already contains a python dict.
I have added changes in request.py in falcon framework to parse application/x-www-form-urlencoded and multipart/from-data.
I have raised pull request - https://github.com/falconry/falcon/pull/1236 but it is not yet merged in master.
Check this - https://github.com/branelmoro/falcon
I have added new code to parse POST, PUT and DELETE application/x-www-form-urlencoded and multipart/form-data.
Text fields will be available in req.form_data dictionary and upload file buffer stream will be available in req.files dictionary.
I hope this will help to access POST and GET parameters separately and we will be able to upload files as well.
Good thing about the change is that it will not load entire uploaded file in memory.
Below is sample code to show how to use POST, PUT and DELETE application/x-www-form-urlencoded and multipart/form-data:
import falcon
class Resource(object):
def on_post(self, req, resp):
# req.form_data will return dictionary of text field names and their values
print(req.form_data)
# req.form_data will return dictionary of file field names and
# their buffer class FileStream objects as values
print(req.files)
# support we are uploading a image.jpg in `pancard` file field then
# req.files["pancard"] will be FileStream buffer object
# We can use set_max_upload_size method to set maximum allowed
# file size let say 1Mb = 1*1024*1024 bytes for this file
req.files["pancard"].set_max_upload_size(1*1024*1024)
# We can use uploadto method to upload file on required path (Note: absolute filepath is required)
# This method returns boolean - `True` on successful upload
# and if upload is unsuccessful then it returns `False` and sets error on failure.
path = "/tmp/" + req.files["pancard"].name
response = req.files["pancard"].uploadto("/tmp/" + path)
print(response)
# Once file is uploaded sucessfully, we can check it's size
print(req.files["pancard"].size)
# If file is not uploaded sucessfully, we can check it's error
print(req.files["pancard"].error)
resp.body = "Done file upload"
resp.status = falcon.HTTP_200
# falcon.API instances are callable WSGI apps
app = falcon.API()
things = Resource()
# things will handle post requests to the '/post_path' URL path
app.add_route('/post_path', things)
Do let me know if you have any doubts.
So far... for me bounded_stream.read() and stream.read() both get the posted data as type str. I have only found one way around the issue so far:
def on_post(self, req, resp):
posted_data = json.loads(req.stream.read())
print(str(type(posted_data)))
print(posted_data)
Loading the string into a json dict once the posted data is received is my only solution that I can come up with
Here's something I used while designing an API.
import falcon
import json
class VerifierResource():
def on_post(self, req, resp):
credentials = json.loads(req.stream.read())
if credentials['username'] == USER \
and credentials['passwd'] == PASSWORD:
resp.body = json.dumps({"status": "verified"})
else:
resp.body = json.dumps({"status": "invalid"})
api = falcon.API()
api.add_route('/verify', VerifierResource())
This returns a serialized JSON with corresponding response body.
there is a sample way to get media from body. I use to get the body in the post method:
def on_post(req,resp)
arguments = {}
# get body media on post method
body = req.get_media()
if 'something' in body:
arguments['something'] = body['something']
send body content type Media-Type and print resp or use in code, but if want to send JSON body your code should cover give JSON parameters.
Do let me know if you have any doubts.
I'm very new to web2py and I'm trying to use it for testing remote server's application (I send a http POST request using python requests with file to process and expect to get counter POST request with report in json and display it in shell or save to file). I found following code for similar issue for XML data
# Controller code:
def index():
response.headers['content-type'] = 'text/xml'
xml = request.body.read() # retrieve the raw POST data
if len(xml) == 0:
xml = '<?xml version="1.0" encoding="utf-8" ?><root>no post data</root>'
return response.render(dict(xml=XML(xml)))
# View code:
{{=xml}}
but I can't make proper changes that will allow to use it for my purpose.
So the question is: how to simply receive json data via POST request and save it directly on my computer or to display it somehow using web2py? No buttons, upload fields, data bases needed.. only to get data from incoming request
In your client:
import requests
:
your_url='http://domain.com/app/controllerfile/j'
r=requests.post(your_url, json=jsonData)
In a web2py controller file 'controllerfile':
import json
def j():
with open("json.txt","a") as f:
json.dump(request.vars,f)
return
I am trying to upload a file to s3 from a form via ajax. I am using fineuploader http://fineuploader.com/ on the client side and webapp2 on the server side. it sends the parameter as qqfile in the request and I can see the image data in the request headers but I have no idea how to get it back in browsers that do not use the multipart encoding.
This is how I was doing it in the standard html form post with multipart.
image = self.request.POST["image"]
this gives me the image name and the image file
currently I have only been able to get the image filename back not the data with
image = self.request.get_all('image')
[u'image_name.png']
when using the POST I get a warning about the content headers being application/octet-stream
<NoVars: Not an HTML form submission (Content-Type: application/octet-stream)>
How do I implement a BlobStoreHandler in webapp2 outside of GAE?
Your question code is not very clear to me. But you can use an example.
Have a look at this article from Nick Johnson. He implements a dropbox service using app engine blobstore and Plupload in the client : http://blog.notdot.net/2010/04/Implementing-a-dropbox-service-with-the-Blobstore-API-part-2
I ended up using fineuploader http://fineuploader.com/ which sends a multipart encoded form to my handler endpoint.
inside the handler I could simply just reference the POST and then read the FieldStorage Object into a cStringIO object.
image = self.request.POST["qqfile"]
imgObj = cStringIO.StringIO(image.file.read())
# Connect to S3...
# create s3 Key
key = bucket.new_key("%s" % uuid.uuid4());
# guess mimetype for headers
file_mime_type = mimetypes.guess_type(image.filename)
if file_mime_type[0]:
file_headers = {"Content-Type": "%s" % file_mime_type[0]}
else:
file_headers = None
key.set_contents_from_string(imgObj.getvalue(), headers=file_headers)
key_str = key.key
#return JSON response with key and append to s3 url on front end.
note: qqfile is the parameter fineuploader uses.
I am faking the progress but that is ok for my use case no need for BlobStoreUploadHandler.
I am using Flask (based on Werkzeug) which uses Python.
The user can download a file, I'm using the send_from_directory-function.
However when actually downloading the file, the HTTP header content-length is not set. So the user has no idea how big the file being downloaded is.
I can use os.path.getsize(FILE_LOCATION) in Python to get the file size (in bytes), but cannot find a way to set the content-length header in Flask.
Any ideas?
I needed this also, but for every requests, so here's what I did (based on the doc) :
#app.after_request
def after_request(response):
response.headers.add('Access-Control-Allow-Origin', '*')
return response
Since version 0.6 the canonical way to add headers to a response object is via the make_response method (see Flask docs).
def index():
response = make_response(render_template('index.html', foo=42))
response.headers['X-Parachutes'] = 'parachutes are cool'
return response
I believe you'd do something like this (untested):
from flask import Response
response = Response()
response.headers.add('content-length', str(os.path.getsize(FILE_LOCATION)))
See: Werkzug's Headers object and Flask's Response object.