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FLASK REST API returns 400 on POST

I'm building a REST API for a simple Todo application using flask and SQLAlchemy as my ORM. I am testing my API using Postman. I'm on a windows 10 64-bit machine.
A GET request works and returns the data that I've entered into my database using python.
I'd like to try to add a task now. But when I POST my request, I receive an error.
My route in flask looks like this.
#add task
#app.route('/todo/api/v1.0/tasks', methods=['POST'])
def create_task():
if not request.json or not 'title' in request.json:
raise InvalidUsage('Not a valid task!', status_code=400)
task = {
'title': request.json['title'],
'description': request.json['description'],
'done': False
}
Todo.add_todo(task)
return jsonify({'task': task}), 201
And the method it's calling on the Todo object looks like this.
def add_todo(_title, _description):
new_todo = Todo(title=_title, description=_description , completed = 0)
db.session.add(new_todo)
db.session.commit()
What I've tried
I thought that maybe the ' in my Postman Params was causing an issue so I removed them. But I still get the same error.
Then I thought that maybe the way that Postman was sending the POST was incorrect so I checked to make sure that the Content-Type headers was correct. It is set to application/json
Finally, to confirm that the issue was that flask didn't like the request, I removed the check in the add task route to make sure the request had a title. So it looks like this.
if not request.json:
And I get the same error. So I think that the problem must be with how I'm actually sending the POST rather than some kind of formatting issue.
My entire code looks like this.
from flask import Flask
from flask_sqlalchemy import SQLAlchemy
import json
from flask import jsonify
from flask import request
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:///todo.db'
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
db = SQLAlchemy(app)
class Todo(db.Model):
id = db.Column(db.Integer, primary_key=True)
title = db.Column(db.String(300), unique=False, nullable=False)
description = db.Column(db.String(), unique=False, nullable=False)
completed = db.Column(db.Boolean, nullable=False)
def json(self):
return {'id': self.id,'title': self.title, 'description': self.description, 'completed': self.completed}
def add_todo(_title, _description):
new_todo = Todo(title=_title, description=_description , completed = 0)
db.session.add(new_todo)
db.session.commit()
def get_all_tasks():
return [Todo.json(todo) for todo in Todo.query.all()]
def get_task(_id):
task = Todo.query.filter_by(id=_id).first()
if task is not None:
return Todo.json(task)
else:
raise InvalidUsage('No task found', status_code=400)
def __repr__(self):
return f"Todo('{self.title}')"
class InvalidUsage(Exception):
status_code = 400
def __init__(self, message, status_code=None, payload=None):
Exception.__init__(self)
self.message = message
if status_code is not None:
self.status_code = status_code
self.payload = payload
def to_dict(self):
rv = dict(self.payload or ())
rv['message'] = self.message
return rv
#app.route('/')
def hello_world():
return 'Hello to the World of Flask!'
#get all tasks
#app.route('/todo/api/v1.0/tasks', methods=['GET'])
def get_tasks():
return_value = Todo.get_all_tasks()
return jsonify({'tasks': return_value})
#get specific task
#app.route('/todo/api/v1.0/tasks/<int:task_id>', methods=['GET'])
def get_task(task_id):
task = Todo.get_task(task_id)
#if len(task) == 0:
#raise InvalidUsage('No such task', status_code=404)
return jsonify({'task': task})
#add task
#app.route('/todo/api/v1.0/tasks', methods=['POST'])
def create_task():
if not request.json or not 'title' in request.json:
raise InvalidUsage('Not a valid task!', status_code=400)
task = {
'title': request.json['title'],
'description': request.json['description'],
'done': False
}
Todo.add_todo(task)
return jsonify({'task': task}), 201
#update task
#app.route('/todo/api/v1.0/tasks/<int:task_id>', methods=['PUT'])
def update_task(task_id):
task = [task for task in tasks if task['id'] == task_id]
if len(task) == 0:
raise InvalidUsage('No provided updated', status_code=400)
if not request.json:
raise InvalidUsage('request not valid json', status_code=400)
if 'title' in request.json and type(request.json['title']) != unicode:
raise InvalidUsage('title not unicode', status_code=400)
if 'description' in request.json and type(request.json['description']) != unicode:
raise InvalidUsage('description not unicode', status_code=400)
if 'done' in request.json and type(request.json['done']) is not bool:
raise InvalidUsage('done not boolean', status_code=400)
task[0]['title'] = request.json.get('title', task[0]['title'])
task[0]['description'] = request.json.get('description', task[0]['description'])
task[0]['done'] = request.json.get('done', task[0]['done'])
return jsonify({'task': task[0]})
#delete task
#app.route('/todo/api/v1.0/tasks/<int:task_id>', methods=['DELETE'])
def delete_task(task_id):
task = [task for task in tasks if task['id'] == task_id]
if len(task) == 0:
raise InvalidUsage('No task to delete', status_code=400)
tasks.remove(task[0])
return jsonify({'result': True})
#app.errorhandler(InvalidUsage)
def handle_invalid_usage(error):
response = jsonify(error.to_dict())
response.status_code = error.status_code
return response
if __name__ == '__main__':
app.run(debug=True)
EDIT:
Turns out I wasn't setting the request type in POSTMAN correctly. I've updated it to 'application/json' in the header. Now I'm receiving a different error.
Bad Request Failed to decode JSON object: Expecting value: line 1
column 1 (char 0)
I've tried all the previous steps as before but I continue to get this error.
EDIT 2:
Per a response below, I tried putting the values into the body of the POST. But I still get back a 400 response.

From the image [second postman screenshot] it looks like you pass data in query string but create_task() expects them in request body.
Either replace all occurrences of request.json with request.args in create_task() (to make it work with query params) or leave it as it is and send data in request body.
curl -X POST http://localhost:5000/todo/api/v1.0/tasks \
-H "Content-Type: application/json" \
-d '{"title":"Learn more flask","description":"its supper fun"}'
Also, take a look at Get the data received in a Flask request.
EDITED
Update your add_todo to something like
#classmethod
def add_todo(cls, task):
new_todo = cls(title=task["title"], description=task["description"], completed=0)
db.session.add(new_todo)
db.session.commit()
Related: generalised insert into sqlalchemy using dictionary.

Middleware logging limitation Django 1.11

Background:
I have integration test which is working fine, but later on failed when I
added the customized middleware
def test_mobile_update_customer(self):
user = User.objects.create(username='warhead')
self.client.force_authenticate(user=user)
mommy.make(Customer, family_name='IBM', created_user=self.soken_staff, updated_user=self.soken_staff)
data = {
"family_name": "C0D1UM"
}
customer = Customer.objects.first()
res = self.client.patch(reverse('api:customer-detail', kwargs={'pk': customer.id}), data=data)
self.assertEqual(200, res.status_code)
customer.refresh_from_db()
self.assertEqual('C0D1UM', customer.family_name)
self.assertEqual('spearhead', customer.created_user.username)
self.assertEqual('warhead', customer.updated_user.username)
Problem:
The middleware break it with Exception
File "/Users/el/Code/norak-cutter/soken/soken-web/soken_web/middleware.py", line 47, in process_request
data['PATCH'] = json.loads(request.body)
File "/Users/el/.pyenv/versions/soken/lib/python3.6/site-packages/django/http/request.py", line 264, in body
raise RawPostDataException("You cannot access body after reading from request's data stream")
django.http.request.RawPostDataException: You cannot access body after reading from request's data stream
The problem is data has been read before the RESTful api do the job.
Then the program raises an exception.
def process_request(self, request):
if request.path.startswith('/api/'):
data = collections.OrderedDict()
data["user"] = request.user.username
data["path"] = request.path
data["method"] = request.method
data["content-type"] = request.content_type
if request.method == 'GET':
data['GET'] = request.GET
elif request.method == 'POST':
data['POST'] = request.POST
# https://stackoverflow.com/questions/4994789/django-where-are-the-params-stored-on-a-put-delete-request
# elif request.method == 'PUT':
# data['PUT'] = json.loads(request.body)
# test_mobile_update_customer
# raise RawPostDataException("You cannot access body after reading from request's data stream")
# django.http.request.RawPostDataException: You cannot access body after reading from request's data stream
# elif request.method == 'PATCH':
# data['PATCH'] = json.loads(request.body)
elif request.method == 'DELETE':
pass
self.__uuid = str(uuid.uuid4())
request_logger.info(f'{self.__uuid} {json.dumps(data)}')
Update2
Attempt:
I change client constructor refer to https://github.com/encode/django-rest-framework/issues/2774
def test_mobile_update_customer(self):
user = User.objects.create(username='warhead')
# self.client.force_authenticate(user=user)
from django.test import Client
client = Client()
client.force_login(user)
mommy.make(Customer, family_name='IBM', created_user=self.soken_staff, updated_user=self.soken_staff)
data = {
"family_name": "C0D1UM"
}
customer = Customer.objects.first()
res = client.patch(reverse('api:customer-detail', kwargs={'pk': customer.id}), data=data, content_type='application/json')
self.assertEqual(200, res.status_code)
customer.refresh_from_db()
self.assertEqual('C0D1UM', customer.family_name)
self.assertEqual('spearhead', customer.created_user.username)
self.assertEqual('warhead', customer.updated_user.username)
It does not work. The Client misinterpret the payload
>>> res.content
b'{"detail":"JSON parse error - Expecting property name enclosed in double quotes: line 1 column 2 (char 1)"}'
Workaround:
I don't know this is correct for all cases or not, but I workaround by this
test.py
https://gist.github.com/elcolie/88eb7c90cfca1c369a020ac232c7fbcc
middleware.py
https://gist.github.com/elcolie/5d9b1a2f890a0efcb46fdb95c0e90908
result.py
https://gist.github.com/elcolie/298e595b404c1a5839ed8dd584d2f07f
Question:
How do I do integration test of PATCH with the same time that testcase will not break by my middleware?
Right now I have to choose either one of them.

Django Unit Testing testing views

I am testing my views using Django Unit testing. I am making get and post requests with params to check what status i get back.
But the problem how to check for context variables which are retuned in the response?
For example, on the View Cities page, I make a get request, the context dict in the view has the variable cities. So I want to check for context.
resp = self.client.post(
path=reverse('upload_video'),
data={"video_url": video_url, "pro": 1}
)
self.assertEqual(resp.status_code, 200)
Condition is True both ways, if the form is invalid or valid it returns 200. If I can check for context, then I can check what has been retuned from the view in response.
What I tried
=> resp.__dict__
{'templates': [], '_handler_class': None, '_headers': {'vary': ('Vary', 'Cookie'), 'content-type': ('Content-Type', 'application/json')}, '_charset': 'utf-8', '_closable_objects': [], 'cookies': <SimpleCookie: >, 'client': <django.test.client.Client object at 0x112bace10>, '_base_content_is_iter': False, 'context': None, 'request': {u'CONTENT_LENGTH': 202, u'wsgi.input': <django.test.client.FakePayload object at 0x113667990>, u'REQUEST_METHOD': 'POST', u'PATH_INFO': '/upload/video/modal/', u'CONTENT_TYPE': u'multipart/form-data; boundary=BoUnDaRyStRiNg', u'QUERY_STRING': ''}, '_container': ['{"error": {"msg": "Pro: Select a valid choice. That choice is not one of the available choices.", "head": null}}']}
Check _container has that variable. The form is invalidated, and retuned an error in the context. but when I do the following i get None
=> resp.context
None
Test
import os
from django.contrib.auth import authenticate
from django.core.urlresolvers import reverse
from django.test import TestCase
def test_video_upload(self):
""" Test that video upload is successful """
self.create_and_login(username="su", password="su", is_superuser=True)
video_urls = [
u"https://www.youtube.com/watch?v=abc",
u"https://vimeo.com/32222",
u"http://www.dailymotion.com/video/rer"
]
for video_url in video_urls:
resp = self.client.post(
path=reverse('upload_video'),
data={"video_url": video_url, "pro": 1}
)
set_trace() #Breakpoint
a = resp.context[-1] # <=== Not getting it here.
self.assertEqual(resp.status_code, 200) #passes
videos = Video.objects.all()
self.assertEqual(len(videos), 3)
View
ctx = {}
if request.method == Enums.Request.POST:
video_form = UploadVideoEasyForm(data=request.POST)
if video_form.is_valid():
video, log = video_form.save(request=request)
msg = 'Successfully Uploaded, View: here'.format(video.get_absolute_url())
ctx[Enums.ResponseAlert.Success] = {'msg': msg}
else:
ctx[Enums.ResponseAlert.Error] = make_alert(msg=form_error_to_string(video_form))
return HttpResponse(json.dumps(ctx), content_type="application/json")
elif request.method == Enums.Request.GET:
ctx['upload_video'] = UploadVideoEasyForm()
if request.user.is_authenticated() and request.user.is_superuser:
return render_to_response('new/modals/upload_video.html', context_instance=RequestContext(request, ctx))
Cheers.

The resp (An instance of django.test.Response) should have an context attribute.
You can access context value using context[..]:
self.assertEqual(resp.context['cities'], ...)

Django Responds code 500 no matter what

I have a method in Django where I get POST data from a mobile app and all I do is save it and send a Response. The problem is though the the data gets saved but no matter what the app receives the response code 500.
<Response [500]>
code:
#csrf_exempt
def store_recordings(request):
if request.method == 'POST':
print "In POST",request.POST
driverName = request.POST['driverName']
driverMobileNum = request.POST['driverMobileNum']
customerMobileNum = request.POST['customerMobileNum']
salesOrderNo = request.POST['salesOrderNo']
callRecord = request.POST['callRecord']
latitude = request.POST['latitude']
longitude = request.POST['longitude']
callStart = request.POST['callStart']
callEnd = request.POST['callEnd']
callDuration = request.POST['callDuration']
callType = request.POST['callType']
driverrecording = DriverRecording(driverName=driverName,driverMobileNum=driverMobileNum,customerMobileNum=customerMobileNum,salesOrderNo=salesOrderNo,callRecord=callRecord,latitude=latitude,longitude=longitude,callStart=callStart,callEnd=callEnd,callDuration=callDuration,callType=callType)
save_or_not = driverrecording.save()
driverexist = DriverNames.objects.all()
new_driver_flag = False
driverName_list = [each.driverName for each in driverexist]
driverName_list = list(set(driverName_list))
if driverName in driverName_list:
pass
else:
DriverNames(driverName=driverName,driverMobileNum=driverMobileNum).save()
return HttpResponse(status=201)
else:
return HttpResponse(status=400)
I am perplexed what is the problem.
Thanks.

Almost certainly, one or more of those fields is not being sent, so you are getting a KeyError. If you set DEBUG to True you would see the traceback.
You should be using Django's forms framework, instead of directly accessing the POST data. That will validate the input and allow you to display any errors.

Django & Haystack: Beautify the search url

I have a problem with Django and Haystack. I'm trying to beautify the url (example.com/search/?q=hey in example/search/hey/) as follows:
def go(request):
"""
Search > Beautify
"""
search_query = request.GET.get('q', None)
return HttpResponseRedirect(reverse('search.views.root', kwargs={
'search_query': search_query,
}))
def root(request, search_query):
"""
Search > Root
"""
form = HaystackSearchForm(request.GET)
tutorials = form.search()
return render(request, 'search/search_root.html', {
'search_query' : search_query,
'tutorials' : tutorials,
})
The problem is that it doesn't work because the request for the go function is not the same than the root function. I want to find a way to pass the appropriate request to the HaystackForm (which mean with the query).