node-esl
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FreeSWITCH ESL implementation for Node.js; implements the full Event Socket Library specified in: http://wiki.freeswitch.org/wiki/Esl
FreeSWITCH ESL Bindings for Node.js ![Build Status](https://travis-ci.org/englercj/node-esl.svg?branch=master)
A Library for handling low-level FreeSWITCH ESLconnections, and associated ESLevents.
API Documentation - API Events - Event Socket Library Spec
Purpose
This library was written to implement the full Event Socket Library interface, and provide a meaningful semantic when dealing with FreeSWITCH in Node.js.
This library supports both "Inbound" (connection going into FreeSWITCH) and "Outbound" (connections
coming out of FreeSWITCH). Also included is a helper Server
object that manages multiple
Connection
objects; making it trivial to have multiple "Outbound" connections from FreeSWITCH.
Installation
The easiest way to install is via npm:
npm install modesl
As in "Mod ESL".
Usage
The most basic usage example is to open a connection, and send a status command:
const esl = require('modesl');
const connectionOptions = {
host: '127.0.0.1',
port: 8021,
};
const connection = esl.Connection.createInbound(connectionOptions, 'ClueCon', function ()
{
connection.api('status', function (res)
{
console.log(res.getBody());
});
});
Something to be aware of is that all functions that interact with FreeSWITCH are asynchronous on the Library side.
However, there are many functions (api
, execute
, etc) that are synchronous on the FreeSWITCH side. Because of this
the event you will get back in your callback on, for example, api
and the same command on bgapi
will be different.
The api
command's callback will be executed immediately when the command/reply
message is received, with all the
returned data. However, that same command using bgapi
will not call the callback when the command/reply
message
is received, this is because FreeSWITCH returns the command/reply
message immediately for background commands before
the command is run. The Library will automatically track the command, and call the callback on the BACKGROUND_JOB
message that denotes a completed Background Job.
The body for the same command issued with api
and bgapi
should be the same; even when the headers, event type, and
time it takes for the callback to execute are different. The Library attempts to smooth these differences out by providing
a common interface, even though behind the scenes things are quite different.
License
This module is distributed under the MIT License.