# Titanium.Network.Socket.TCP

TCP socket that implements the Titanium.IOStream interface.

Availability
1.7
1.7
9.2.0

# Overview

Most socket operations are asynchronous. When you create a socket, you can define callback functions to receive the results of API calls, as well as to handle incoming data.

For example, for a client-side socket, you define Titanium.Network.Socket.TCP.connected and Titanium.Network.Socket.TCP.error callback functions.

To connect to a remote host, call the socket's Titanium.Network.Socket.TCP.connect method. If the socket connects successfully, your connected callback is invoked, and you can send and receive data on the socket. If the socket connection fails, your error callback is invoked.

After a socket is connected, you can access it like any other Titanium.IOStream. Note that the socket's read and write methods may block, so in most cases you should use the asynchronous Titanium.Stream.read, Titanium.Stream.write and Titanium.Stream.pump methods provided by the Titanium.Stream module, rather than using the socket object's read and write methods directly.

A familiarity with the basics of BSD socket programming is recommended before using sockets with Titanium.

Use the Titanium.Network.Socket.createTCP method to create a TCP socket.

# Examples

# Simple Socket IO using Stream.pump

The following example uses the Titanium.Stream.pump method from the Titanium.Stream module to read data from a socket. The pump method registers a callback that is called repeatedly to process incoming data from the socket.

var socket = Ti.Network.Socket.createTCP({
    host: 'blog.example.com', port: 80,
    connected: function (e) {
        Ti.API.info('Socket opened!');
        Ti.Stream.pump(e.socket, readCallback, 1024, true);
        Ti.Stream.write(socket, Ti.createBuffer({
            value: 'GET http://blog.example.com/index.html HTTP/1.1\r\n\r\n'
        }), writeCallback);
    },
        error: function (e) {
        Ti.API.info('Error (' + e.errorCode + '): ' + e.error);
    },
});
socket.connect();

function writeCallback(e) {
    Ti.API.info('Successfully wrote to socket.');
}

function readCallback(e) {
    if (e.bytesProcessed == -1)
    {
        // Error / EOF on socket. Do any cleanup here.
        ...
    }
    try {
        if(e.buffer) {
            var received = e.buffer.toString();
            Ti.API.info('Received: ' + received);
        } else {
            Ti.API.error('Error: read callback called with no buffer!');
        }
    } catch (ex) {
        Ti.API.error(ex);
    }
}

# Listening Socket Example

The following sample shows a trivial example of using a listening socket. In this case, the application simply sends messages to itself, using the loopback address.

// Hostname to listen on/connect to. Here we use the loopback
// address. iOS also supports Ti.Platform.address (the address of
// the WiFi interface).
// Android supports only the loopback address.

var hostname = '127.0.0.1';

var clientSocket = Ti.Network.Socket.createTCP({
    host : hostname,
    port : 40404,
    connected : function(e) {
        Ti.API.info('Client socket connected!');
        Ti.Stream.pump(e.socket, pumpCallback, 1024, true);
        e.socket.write(Ti.createBuffer({
            value : 'A message from a connecting socket.'
        }));
    },
    error : function(e) {
        Ti.API.info('Error (' + e.errorCode + '): ' + e.error);
    }
});

function writeCallback(e) {
    Ti.API.info('Successfully wrote to socket.');
}

function pumpCallback(e) {
    // Has the remote socket closed its end?
    if (e.bytesProcessed < 0) {
        Ti.API.info("Closing client socket.");
        clientSocket.close();
        return;
    }
    try {
        if(e.buffer) {
            var received = e.buffer.toString();
            Ti.API.info('Received: ' + received);
        } else {
            Ti.API.error('Error: read callback called with no buffer!');
        }
    } catch (ex) {
        Ti.API.error(ex);
    }
}

// Create a socket and listen for incoming connections
var listenSocket = Ti.Network.Socket.createTCP({
    host : hostname,
    port : 40404,
    accepted : function(e) {
        // This where you would usually store the newly-connected socket, e.inbound
        // so it can be used for read / write operations elsewhere in the app.
        // In this case, we simply send a message then close the socket.
        Ti.API.info("Listening socket <" + e.socket + "> accepted incoming connection <" + e.inbound + ">");
        e.inbound.write(Ti.createBuffer({
            value : 'You have been connected to a listening socket.\r\n'
        }));
        e.inbound.close();
        // close the accepted socket

    },
    error : function(e) {
        Ti.API.error("Socket <" + e.socket + "> encountered error when listening");
        Ti.API.error(" error code <" + e.errorCode + ">");
        Ti.API.error(" error description <" + e.error + ">");
    }
});
// Starts the socket listening for connections, does not accept them
listenSocket.listen();
Ti.API.info("Listening now...");

// Tells socket to accept the next inbound connection. listenSocket.accepted gets
// called when a connection is accepted via accept()
Ti.API.info("Calling accept.");
listenSocket.accept({
    timeout : 10000
});

// Call connect after a short timeout to ensure the listening socket is ready to go.
Ti.API.info("Setting timer to connect.");
setTimeout(function(e)
{
    Ti.API.info("Calling connect on client socket.");
    clientSocket.connect();
}, 500);

# Properties

# accepted

Availability
1.7
1.7
9.2.0
accepted :Callback<AcceptedCallbackArgs>

Callback to be fired when a listener accepts a connection.


# apiName READONLY

Availability
3.2.0
3.2.0
9.2.0
apiName :String

The name of the API that this proxy corresponds to.

The value of this property is the fully qualified name of the API. For example, Titanium.UI.Button returns Ti.UI.Button.


# bubbleParent

Availability
3.0.0
3.0.0
9.2.0
bubbleParent :Boolean

Indicates if the proxy will bubble an event to its parent.

Some proxies (most commonly views) have a relationship to other proxies, often established by the add() method. For example, for a button added to a window, a click event on the button would bubble up to the window. Other common parents are table sections to their rows, table views to their sections, and scrollable views to their views. Set this property to false to disable the bubbling to the proxy's parent.

Default: true


# connected

Availability
1.7
1.7
9.2.0
connected :Callback<ConnectedCallbackArgs>

Callback to be fired when the socket enters the "connected" state.

Only invoked following a successful connect call.

Can only be modified when this socket is in the INITIALIZED state.


# error

Availability
1.7
1.7
9.2.0
error :Callback<ErrorCallbackArgs>

Callback to be fired when the socket enters the ERROR state.


# host

Availability
1.7
1.7
9.2.0
host :String

The host to connect to or listen on.

Can only be modified when this socket is in the INITIALIZED state.

Supports both IPv4 and IPv6 addresses.


# lifecycleContainer

Availability
3.6.0

The Window or TabGroup whose Activity lifecycle should be triggered on the proxy.

If this property is set to a Window or TabGroup, then the corresponding Activity lifecycle event callbacks will also be called on the proxy. Proxies that require the activity lifecycle will need this property set to the appropriate containing Window or TabGroup.


# listenQueueSize

Availability
1.7
1.7
9.2.0
listenQueueSize :Number

Max number of pending incoming connections to be allowed when the socket is in the LISTENING state.

Any incoming connections received while the max number of pending connections has been reached will be rejected.


# port

Availability
1.7
1.7
9.2.0
port :Number

The port to connect to or listen on.

Can only be modified when this socket is in the INITIALIZED state.


# secure

Availability
12.1.0
secure :Boolean

Creates a secure socket.

Default: false


# state READONLY

Availability
1.7
1.7
9.2.0
state :Number

Current state of the socket.


# timeout

Availability
1.7
1.7
9.2.0
timeout :Number

Timeout, in milliseconds, for connect and all write operations.

Can only be modified when this socket is in the INITIALIZED state.

# Methods

# accept

Availability
1.7
1.7
9.2.0
accept(options) void

Tells a LISTENING socket to accept a connection request at the top of a listener's request queue when one becomes available.

Nonblocking; if there are no connections in the queue, sets a flag so that the socket accepts the next incoming connection immediately.

Takes an argument, an AcceptDict object which assigns options to the new connection. If the socket is already flagged to accept the next connection, the existing accept options will be updated to use the newly specified options object.

The accepted callback is called when a new connection is accepted as a result of calling accept. The callback argument holds a reference to a new socket, representing the accepted connection.

Note that the connected callback is not called on the newly created socket. This is because the socket is created in the CONNECTED state, so it never transitions to the CONNECTED state.

Throws an exception if called on a socket that is not in a LISTENING state.

Parameters

Name Type Description
options AcceptDict

Options to be set on next accepted socket.

Returns

Type
void

# addEventListener

Availability
1.7
1.7
9.2.0
addEventListener(name, callback) void

Adds the specified callback as an event listener for the named event.

Parameters

Name Type Description
name String

Name of the event.

callback Callback<Titanium.Event>

Callback function to invoke when the event is fired.

Returns

Type
void

# applyProperties

Availability
3.0.0
3.0.0
9.2.0
applyProperties(props) void

Applies the properties to the proxy.

Properties are supplied as a dictionary. Each key-value pair in the object is applied to the proxy such that myproxy[key] = value.

Parameters

Name Type Description
props Dictionary

A dictionary of properties to apply.

Returns

Type
void

# close

Availability
1.7
1.7
9.2.0
close() void

Closes a socket.

Throws exception if the socket is not in a CONNECTED or LISTENING state. Blocking.

Returns

Type
void

# connect

Availability
1.7
1.7
9.2.0
connect() void

Attempts to connect the socket to its host/port.

Throws an exception if the socket is in a CONNECTED or LISTENING state. Throws an exception if a valid host and port has not been set on this socket.

Nonblocking; connection attempts are asynchronous.

Returns

Type
void

# fireEvent

Availability
1.7
1.7
9.2.0
fireEvent(name[, event]) void

Fires a synthesized event to any registered listeners.

Parameters

Name Type Description
name String

Name of the event.

event Dictionary

A dictionary of keys and values to add to the Titanium.Event object sent to the listeners.

Returns

Type
void

# isReadable

Availability
1.7
1.7
9.2.0
isReadable() Boolean

Indicates whether this stream is readable.

Returns

True if stream is readable, false otherwise.

Type
Boolean

# isWritable

Availability
1.7
1.7
9.2.0
isWritable() Boolean

Indicates whether this stream is writable.

Returns

True if stream is writable, false otherwise.

Type
Boolean

# listen

Availability
1.7
1.7
9.2.0
listen() void

Attempts to start listening on the socket's host/port.

The listen call will attempt to listen on the specified host and/or port property for the socket if they are set.

Nonblocking; may return before the socket is fully open and listening.

If the socket is already in a LISTENING or CONNECTED state, listen throws an exception and sets the socket state to ERROR, but does not fire the error callback.

Any error encountered after the socket starts listening results in the error callback being fired.

Returns

Type
void

# read

Availability
1.7
1.7
9.2.0
read(buffer[, offset[, length[, resultsCallback]]]) Number

Reads data from this stream into a buffer.

Takes an optional resultsCallback function as the last argument. If specified, the operation is done asynchronously. If no callback is passed in, the operation is done synchronously.

If offset and length are specified, data is written into the buffer starting at position offset. Data is read from this stream until one of the following occurs:

  • the end of this stream is reached
  • the end of the buffer is reached
  • a total of length bytes have been read from the stream

If offset and length are omitted, data is written starting at the beginning of the buffer.

When called synchronously: returns the number of bytes read, or -1 if the end of stream was reached before any data was read.

Returns 0 when called asynchronously.

Throws an exception on error. For example, if the offset value is past the last byte of buffer.

Parameters

Name Type Description
buffer Titanium.Buffer

Buffer to read stream data into.

offset Number

Offset into the buffer to start writing stream data. If specified, length must also be specified.

length Number

Maximum number of bytes to read. If specified, offset must also be specified.

resultsCallback Callback<ReadCallbackArgs>

Function to call with the results of the read operation.

Returns

Number of bytes read.

Type
Number

# removeEventListener

Availability
1.7
1.7
9.2.0
removeEventListener(name, callback) void

Removes the specified callback as an event listener for the named event.

Multiple listeners can be registered for the same event, so the callback parameter is used to determine which listener to remove.

When adding a listener, you must save a reference to the callback function in order to remove the listener later:

var listener = function() { Ti.API.info("Event listener called."); }
window.addEventListener('click', listener);

To remove the listener, pass in a reference to the callback function:

window.removeEventListener('click', listener);

Parameters

Name Type Description
name String

Name of the event.

callback Callback<Titanium.Event>

Callback function to remove. Must be the same function passed to addEventListener.

Returns

Type
void

# write

Availability
1.7
1.7
9.2.0
write(buffer[, offset[, length[, resultsCallback]]]) Number

Writes data from a buffer to this stream.

Takes an optional resultsCallback function as the last argument. If specified, the operation is done asynchronously. If no callback is passed in, the operation is done synchronously.

If offset and length are specified, data is read from the buffer starting at offset. Bytes are read from the buffer and written to the stream until:

  • the end of the buffer is reached
  • length bytes have been written
  • the stream returns an error

If offset and length are omitted, all of the data in the buffer is written to this stream.

Returns the number of bytes actually written when called synchronously.

Returns 0 when called asynchronously.

Throws an exception if an error is encountered.

Parameters

Name Type Description
buffer Titanium.Buffer

Buffer to write to this stream.

offset Number

Offset in the buffer of the first byte to write to the stream. If specified, length must also be specified.

length Number

Maximum number of bytes to write to the stream. If specified, offset must also be specified.

resultsCallback Callback<WriteCallbackArgs>

Function to call with the results of the write operation.

Returns

Number of bytes written.

Type
Number