example

Example

A simple example that shows interaction between two servers as well as Eventcast REPL feature.

Start servers in two terminal windows:

$ node server1
$ node server2

You should see servers print diagnostic info in the console:

$ node server2.js
[2013-07-14T22:37:16.013Z]  INFO: eventcast/84782 on myhost: UDP server started { address: '0.0.0.0', family: 'IPv4', port: 19999 } (id=af64b2ac5ce41d72)
[2013-07-14T22:37:16.015Z]  INFO: eventcast/repl/84782 on myhost: REPL started. (id=af64b2ac5ce41d72, port=20002)
[2013-07-14T22:37:21.012Z]  INFO: eventcast/84782 on myhost:  (id=af64b2ac5ce41d72)
    Incoming message { name: 'server2 here',
      address: '192.168.1.52:19999',
      hostname: 'myhost',
      id: 'af64b2ac5ce41d72',
      time: '2013-07-14T22:37:21.011Z' }

server2 emits event 'server2 here` with current time. You can see the event arrive but INFO log level does not print the arguments. Let's set log level to DEBUG using REPL.

REPL

Connect to server2's REPL:

$ telnet localhost 20002
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
eventcast@myhost> 

While in REPL, you can access the instance via eventcast object. You can emit an event:

eventcast@myhost> eventcast.emit('hello', 'an argument')
false

You see false returned because there are no listeners for event hello on this instance.

In the console of either process you should see something like this:

[2013-07-14T22:51:35.272Z]  INFO: eventcast/84782 on myhost:  (id=faa1bab11c766e0a)
    Incoming message { name: 'hello',
      address: '192.168.1.52:19999',
      hostname: 'mycomputername',
      id: 'faa1bab11c766e0a',
      time: '2013-07-14T22:51:35.267Z' }

Nice. But let's set that log level:

eventcast@myhost> eventcast.logLevel('debug')

And now you can see the event being sent and received:

[2013-07-14T22:38:11.021Z] DEBUG: eventcast/84782 on myhost:  (id=af64b2ac5ce41d72)
    Sending message { name: 'server2 here',
      payload: [ 'time is Sun Jul 14 2013 18:38:11 GMT-0400 (EDT)' ] }
[2013-07-14T22:38:11.021Z]  INFO: eventcast/84782 on myhost:  (id=af64b2ac5ce41d72)
    Incoming message { name: 'server2 here',
      address: '192.168.1.52:19999',
      hostname: 'myhost',
      id: 'af64b2ac5ce41d72',
      time: '2013-07-14T22:38:11.021Z' }
[2013-07-14T22:38:11.022Z] DEBUG: eventcast/84782 on myhost:  (id=af64b2ac5ce41d72)
    Incoming message:
     { name: 'server2 here',
      header: { version: 2, encrypted: false, metaLength: 141 },
      meta: 
       { name: 'server2 here',
         address: '192.168.1.52:19999',
         hostname: 'myhost',
         id: 'af64b2ac5ce41d72',
         time: '2013-07-14T22:38:11.021Z' },
      payload: [ 'time is Sun Jul 14 2013 18:38:11 GMT-0400 (EDT)' ] }