JSONP in Flask

jsonp-in-flask.py

import json
from functools import wraps
from flask import redirect, request, current_app

def support_jsonp(f):
    """Wraps JSONified output for JSONP"""
    @wraps(f)
    def decorated_function(*args, **kwargs):
        callback = request.args.get('callback', False)
        if callback:
            content = str(callback) + '(' + str(f(*args,**kwargs).data) + ')'
            return current_app.response_class(content, mimetype='application/javascript')
        else:
            return f(*args, **kwargs)
    return decorated_function

# then in your view
@default.route('/test', methods=['GET'])
@support_jsonp
def test():
    return jsonify({"foo":"bar"})

Works like a charm, for those of us who don't return a dictionary with "data" and instead returns dump_json output, just change:

content = str(callback) + '(' + str(f(args,*kwargs).data) + ')'

to

content = str(callback) + '(' + str(f(args,*kwargs)) + ')'

Hi,

as far as I saw you always return an http status code equals to 200. When I use the POST method I'd like to have a 201 response. Provided that a changed a little bit your code:

from functools import wraps
from flask import request, current_app

def jsonp(func):
"""Wraps JSONified output for JSONP requests."""
@wraps(func)
def decorated_function(_args, *_kwargs):
callback = request.args.get('callback', False)
if callback:
res = func(_args, *_kwargs)
data = str(res.data)
content = str(callback) + '(' + data + ')'
mimetype = 'application/javascript'
response = current_app.response_class(content, mimetype=mimetype, status=res.status_code)
return response
else:
return func(_args, *_kwargs)
return decorated_function

Why you create so many code?
It is simply, in flask, only decorator and it work!

import flask
def jsonp(func):
  def decorated_function(*args, **kwargs):
        return flask.jsonify(func(*args, **kwargs))
  return decorated_function

@jsonp
def someController():
  return {'json': 'object'}

Move jsonp function in your libs or helpers packeg and only use.

@Zerstoren where is your callback for jsonp?

Thanks for this!

cool!

Response.data should not be used for recent versions of Werkzeug (and thus Flask). So the following uses get_data() and set_data(). Furthermore, using get_data(as_text=True) makes it work with Python3 as well as Python2. I also just modify the original request instead of creating a new one. Is there something wrong with doing that?

def jsonp(func):
    """Wraps JSONified output for JSONP requests."""
    @wraps(func)
    def decorated_function(*args, **kwargs):
        callback = request.args.get('callback', False)
        if callback:
            resp = func(*args, **kwargs)
            resp.set_data('{}({})'.format(
                str(callback),
                resp.get_data(as_text=True)
            ))
            resp.mimetype = 'application/javascript'
            return resp
        else:
            return func(*args, **kwargs)
    return decorated_function

@aisipos
Based on your gist, I edit some place to make json response can contain status code, please see my fork https://gist.github.com/JiaKunUp/a9df722bad15c61ea555fa860997edc9

good job, helped me