Event-API.md

Event API

The events fired by a damas-core server can be listened by an external process using socket.io.

For the internal API specifications, and how it was implemented, please see pull #112.

We provide three events:

• create
• update
• remove (delete)

Javascript

Here is a sample JavaScript client (see damas-socket.js):

var address = location.protocol + '//' + location.host;
var socket = io.connect(address, { path: '/socket.io' });

window.addEventListener('beforeunload', function (event) {
    socket.close();
});

socket.on('connect', function () {
    console.log('Connected to the Socket server ' + address);
});

socket.on('disconnect', function (reason) {
    console.log('Disconnected: ' + reason);
});

socket.on('create', function (nodes) {
    console.log(nodes.length + ' nodes created');
    console.log(nodes);
});

socket.on('update', function (nodes) {
    console.log(nodes.length + ' nodes updated');
    console.log(nodes);
});

socket.on('remove', function (nodes) {
    console.log(nodes.length + ' nodes removed');
    console.log(nodes);
});

Python

Here are examples to catch the events using python-socketio. See the sample Python websocket client.

First, using asyncio module socketio-async:

# Socketio Python client example for damas-core                                                                                                  
#
# pip install "python-socketio[asyncio_client]"
#

import asyncio
import socketio

sio = socketio.AsyncClient()

@sio.event
async def connect():
    print('connection established')

@sio.event
async def disconnect():
    print('disconnected from server')

@sio.event
async def create(nodes):
    print('create')
    print(nodes)

@sio.event
async def update(nodes):
    print('update')
    print(nodes)

@sio.event
async def remove(nodes):
    print('remove')
    print(nodes)

async def main():
    await sio.connect('http://localhost')
    await sio.wait()

if __name__ == '__main__':
    asyncio.run(main())

Or using the standard threaded method:

# Socketio Python client example for damas-core                                                                                                  
#
# pip install "python-socketio[client]"
#

import socketio

sio = socketio.Client()

@sio.event
def connect():
    print('connection established')

@sio.event
def disconnect():
    print('disconnected from server')

@sio.event
def create(nodes):
    print('create')
    print(nodes)

@sio.event
def update(nodes):
    print('update')
    print(nodes)

@sio.event
def remove(nodes):
    print('remove')
    print(nodes)

sio.connect('http://localhost')
sio.wait()