Waiting for and retrieving data

This example illustrates using a Server-Sent Event (SSE) connection to receive data. The advantage of using an SSE is that you do not have to write a polling loop to check for new data.

Creating a Granta Integration Service session

The first part of this script (creating a session) is the same as in the Getting Started example:

import requests
import json
import webbrowser
import msal # pip install msal
import sseclient # pip install sseclient
from itertools import islice

# Authentication parameters for Ansys ID
ansys_id_client_id = "28982bbf-f354-4e48-8bfb-e542d44c588c"
ansys_id_authority = "https://ansysaccount.b2clogin.com/ansysaccount.onmicrosoft.com/B2C_1A_ANSYSID_SIGNUP_SIGNIN"
scope = "https://ansysaccount.onmicrosoft.com/AnsysID/Authentication"

# Use Microsoft Authentication Library (MSAL) to log in using the system browser
token_resp = msal.PublicClientApplication(ansys_id_client_id, authority=ansys_id_authority).acquire_token_interactive(scopes=[scope], port=32284)

# Store the token from logging in for use in subsequent HTTP requests
auth_header = {"Authorization": f"Bearer {token_resp['access_token']}"}

host = "https://cloudserver.com/is"

sessions_endpoint = f"{host}/api/v1/sessions/"

# Create a session. Set a title for the Granta Material Picker. Store the response
put_session_resp = requests.post(sessions_endpoint, json={'name':'My Application', 'settings':{'title':'My Application', 'packageName':'Workbench'}}, headers=auth_header, verify=0).json()

# Launch default browser at the Granta Material Picker session
webhost = "https://cloudserver.com"

webbrowser.open(f"{webhost}/grantami/#/granta-material-picker?sessionId={put_session_resp['id']}")

Opening an SSE connection

Next we add the code to connect via SSE:

messages = sseclient.SSEClient(f"{sessions_endpoint}{put_session_resp['id']}/data/sse", headers=auth_header, verify=0)

This connection will stay open indefinitely, and you can receive data on this connection as soon as it is available.

To demonstrate receiving data from the SSE connection, add:

for event in islice((msg for msg in messages if msg.data), 3):
    print(f"Event received: {event.data}")

This waits for events that have data and provides the information. In this example we wait for 3 events. An event will fire when you click "Fetch material data" in the Granta Material Picker.

Ending the session

To close the session down and ensure no more materials can be received, send an HTTP DELETE request to the session URL:

requests.delete(f"{sessions_endpoint}{put_session_resp['id']}", json={}, headers=auth_header, verify=0)
print("Session deleted")