Switchboard Python

Switchboard Python provides helpers for writing Switchboard workers and clients in Python.

Installation

It's simplest to install this library from PyPi:

pip install switchboard-python

To build from source:

# Building
./setup.py build

# Running the tests
./setup.py test

# Development install
pip install -e .

# Actual install
pip install .

Usage

The switchboard.Client class is used to interact with both Switchboard workers and clients.

Assuming that the Switchboard application is running, the following example opens a connection to the server over the worker interface, and sends a batch request with a connect command (see the interfaces guide for command documentation).

worker = switchboard.Client("ws://192.168.50.2:8080/workers")
worker.connect()
worker.send_cmds(("connect", CONN_SPEC))
worker.run_forever()

To handle command responses, send_cmds returns a promise that is fulfilled by the tuple (cmds, resps) when the command's responses arrive, where cmds is the list of commands given to send_cmds, and resps is the list of responses returned by Switchboard.

def handle_get_mailboxes((cmds, resps)):
    print "For cmds", cmds, ", received resps:", resps

worker.send_cmds(("getMailboxes", {}).then(handle_get_mailboxes)

To add commands on connect, and/or handling of unsolicited messages subclass the base switchboard.Client -- an unsolicited message is not sent in response to a command, but when the server has new information, such as a new emails arriving

class TheWorker(switchboard.Client):
    def opened(self):
        print "Connected to Switchboard, issuing watchAll cmd."
        worker.send_cmds(("watchAll", {}))

    def received_unsolicited(resps):
        print "Received unsolicited resps from server:", resps
        for resp in resps:
            if resp[0] == 'newMessage':
                print "New message:", resp[1]


worker = TheWorker("ws://127.0.0.1:8080/workers")
worker.connect()
worker.run_forever()

Examples

All examples are located under /examples. Each example uses command line arguments which you can investigate via:

./examples/example.py --help

listener.py

This worker provides a simple example of bidirectional communication using the Switchboard worker interface. It listens for Switchboard to notify it of new emails, then fetches the raw email and parses it using the Python email module:

./examples/listener.py

apnsworker.py

This worker sends new email Apple Push Notifications to an iOS client given an APNS certificate, key, and pushtoken.

Note: it does not map from account to push token when sending push notifications -- it only sends the push notifications using the provided push token:

./examples/apnsworker.py --cert "path/to/cert.pem" --key "path/to/key.pem" --pushtoken "target users hex pushtoken"

twilioworker.py

This worker is similar to apnsworker.py, except instead of sending APNs when a new email arrives, it sends a text message via Twilio:

./examples/twilioworker.py --sid "twilio sid" --token "twilio token" --to "to phone #" --from "from phone #"