Omniscope Help Center

Hi Simon,

We've put together a workflow with a Python block that demonstrates how to do this:

https://omniscope.me/Forums/POST+to+get+auth+token+before+downloading.iox/

You won't be able to execute this locked project, but feel free to copy/paste the Python into your own workflow, or download an IOZ of this project and import it locally.

For convenience here's the python code from inside that project; see comments inline:

# This script simulates doing a POST request to obtain an auth token
# then doing a GET request to retrieve a CSV, passing the auth token as a HTTP header.

# This is a common lifecycle for restricted-access API requests.

# In both cases we fake-up the remote server by using the handy postman-echo service
# and actually sending the data we are expecting to be returned.
# See https://docs.postman-echo.com/

# In the real world, for the first request, you'll be sending username and password,
# and getting back a token which you can't predict. And for the second request,
# you'll be hitting a URL which retrieves CSV data held remotely.

import urllib.request
import json
import pandas as pd

# Request the auth token; store in 'token' variable:
req = urllib.request.Request(url="https://postman-echo.com/post")
req.add_header('Content-Type', 'application/json; charset=utf-8')
responseData = urllib.request.urlopen(req, json.dumps({'token': 'abcd1234'}).encode('utf-8')).read().decode()
token = json.loads(responseData)['data']['token']

# Request the CSV data, passing the auth token:
req = urllib.request.Request(url="https://postman-echo.com/get?data=a%2Cb%2Cc%0A1%2C2%2C3%0A4%2C5%2C6%0A")
req.add_header('Authorization', 'Token '+token)
responseData = urllib.request.urlopen(req).read().decode()
csv = json.loads(responseData)['args']['data']

# Parse and return the CSV:
output_data = pd.read_csv(pd.compat.StringIO(csv))

Just to add that it’s now possible to add HTTP headers and parameters to the HTTP requests in the File block, so effectively you don’t need a custom block, but just a File block to connect to any REST API out there.