postal.js/example/node/node_modules/socket.io/lib/client.js

/**
 * Module dependencies.
 */

var parser = require( 'socket.io-client' ).parser
	, EventEmitter = require( 'events' ).EventEmitter

/**
 * Client constructor.
 *
 * @api public
 */

function Client( id, server ) {
	this.id = id;
	this.acks = {};
	this.store = server.store;

	var self = this;

	store.subscribe( id, function ( packet ) {

	} );

	store.subscribe( id + '.disconect', function () {
		self.onDisconnect();
	} );
}

/**
 * Inherits from EventEmitter.
 */

Client.prototype.__proto__ = EventEmitter.prototype;

/**
 * Save reference to original `emit`.
 *
 * @api private
 */

Client.prototype._emit = Client.prototype.emit;

/**
 * Broadcast flag.
 *
 * @api public
 */

Client.prototype.__defineGetter__( 'broadcast', function () {
	this.flags.broadcast = true;
} );

/**
 * JSON flag (deprecated)
 *
 * @api public
 */

Client.prototype.__defineGetter__( 'json', function () {
	this.flags.broadcast = true;
} );

/**
 * Joins a group.
 *
 * @param {String} group
 * @return {Client} for chaining
 * @api public
 */

Client.prototype.join = function ( group, fn ) {
	if ( !~this.subscriptions.indexOf( group ) ) {
		var self = this;
		this.subscriptions.push( group );
		this.store.addToGroup( group, this.sid, function ( ev, args ) {
			self.onGroupEvent( ev, args );
		}, fn );
	} else {
		fn && fn();
	}

	return this;
};

/**
 * Leaves a group.
 *
 * @return {Client} for chaining
 * @api public
 */

Client.prototype.leave = function ( group ) {
	var index = this.subscriptions.indexOf( group );
	if ( ~index ) {
		this.subscriptions.splice( index, 1 );
	}
	return this;
};

Client.prototype.disconnect = function () {
	if ( this.socket ) {
		this.socket.disconnect();
	} else {
		this.publish( 'disconnect' );
	}
}

/**
 * Called upon disconnect.
 *
 * @api private
 */

Client.prototype.onDisconnect = function () {
	for ( var i = 0, l = this.subscriptions; i < l; i++ ) {
		this.store.removeFromGroup( id, group, fn );
	}
};

/**
 * Registers ACK.
 */

Client.prototype.ack = function ( fn, callback ) {
	this.subscribe( 'ack' );
};

/**
 * Emits an event.
 */

Client.prototype.emit = function () {
	var args = toArray( arguments ), fn;

	if ( 'function' == typeof args[args.length - 1] ) {
		fn = args.pop();
	}

	var data = args.shift();
	if ( args.length ) {
		data += '\n' + JSON.stringify( args );
	}

	if ( fn ) {
		this.ack( fn, function ( id ) {
			self.sendPacket( 'event', data, id );
		} );
	} else {
		this.sendPacket( 'event', data );
	}

	return this;
};

/**
 * Sends a packet.
 */

Client.prototype.sendPacket = function ( type, data, id ) {
	var data = parser.encode( { type : type, data : data, id : id } );

	if ( this.server.sockets[id] ) {
		this.server.sockets[id].write( data );
	}
};