The Socket class enables code to establish Transport Control Protocol (TCP) socket connections for sending and receiving binary data. The Socket class is useful for working with servers that use binary protocols.

To use the methods of the Socket class, first use the constructor, new Socket, to create a Socket object.

A socket transmits and receives data asynchronously.

On some operating systems, flush() is called automatically between execution frames, but on other operating systems, such as Windows, the data is never sent unless you call flush() explicitly. To ensure your application behaves reliably across all operating systems, it is a good practice to call the flush() method after writing each message (or related group of data) to the socket.

In Adobe AIR, Socket objects are also created when a listening ServerSocket receives a connection from an external process. The Socket representing the connection is dispatched in a ServerSocketConnectEvent. Your application is responsible for maintaining a reference to this Socket object. If you don't, the Socket object is eligible for garbage collection and may be destroyed by the runtime without warning.

SWF content running in the local-with-filesystem security sandbox cannot use sockets.

Socket policy files on the target host specify the hosts from which SWF files can make socket connections, and the ports to which those connections can be made. The security requirements with regard to socket policy files have become more stringent in the last several releases of Flash Player. In all versions of Flash Player, Adobe recommends the use of a socket policy file; in some circumstances, a socket policy file is required. Therefore, if you are using Socket objects, make sure that the target host provides a socket policy file if necessary.

The following list summarizes the requirements for socket policy files in different versions of Flash Player:

  • In Flash Player 9.0.124.0 and later, a socket policy file is required for any socket connection. That is, a socket policy file on the target host is required no matter what port you are connecting to, and is required even if you are connecting to a port on the same host that is serving the SWF file.
  • In Flash Player versions 9.0.115.0 and earlier, if you want to connect to a port number below 1024, or if you want to connect to a host other than the one serving the SWF file, a socket policy file on the target host is required.
  • In Flash Player 9.0.115.0, even if a socket policy file isn't required, a warning is displayed when using the Flash Debug Player if the target host doesn't serve a socket policy file.
  • In AIR, a socket policy file is not required for content running in the application security sandbox. Socket policy files are required for any socket connection established by content running outside the AIR application security sandbox.

For more information related to security, see the Flash Player Developer Center Topic: <a href="http://www.adobe.com/go/devnet_security_en" scope="external">Security

@event close Dispatched when the server closes the socket

				 connection.
				 The `close` event is dispatched only when the server
				 closes the connection; it is not dispatched when you
				 call the `Socket.close()` method.

@event connect Dispatched when a network connection has been

				 established.

@event ioError Dispatched when an input/output error occurs that

				 causes a send or load operation to fail.

@event securityError Dispatched if a call to Socket.connect() attempts

				 to connect to a server prohibited by the caller's
				 security sandbox or to a port lower than 1024 and no
				 socket policy file exists to permit such a
				 connection.
				 **Note:** In an AIR application, content running in
				 the application security sandbox is permitted to
				 connect to any server and port number without a
				 socket policy file.

@event socketData Dispatched when a socket has received data.

				 The data received by the socket remains in the socket
				 until it is read. You do not have to read all the
				 available data during the handler for this event.

				 Events of type `socketData` do not use the
				 `ProgressEvent.bytesTotal` property.

Constructor

new (?host:String, port:Int = 0)

Creates a new Socket object. If no parameters are specified, an initially disconnected socket is created. If parameters are specified, a connection is attempted to the specified host and port. Note: It is strongly advised to use the constructor form without parameters, then add any event listeners, then call the connect method with host and port parameters. This sequence guarantees that all event listeners will work properly.

@event connect Dispatched when a network connection has been

				 established.

@event ioError Dispatched when an input/output error occurs that

				 causes the connection to fail.

@event securityError Dispatched if a call to Socket.connect()

				 attempts to connect either to a server that
				 doesn't serve a socket policy file, or to a
				 server whose policy file doesn't grant the
				 calling host access to the specified port. For
				 more information on policy files, see "Website
				 controls (policy files)" in the _ActionScript 3.0
				 Developer's Guide_ and the Flash Player Developer
				 Center Topic: <a
				 href="http://www.adobe.com/go/devnet_security_en"
				 scope="external">Security</a>.

Parameters:

host

A fully qualified DNS domain name or an IP address. IPv4 addresses are specified in dot-decimal notation, such as 192.0.2.0. In Flash Player 9.0.115.0 and AIR 1.0 and later, you can specify IPv6 addresses using hexadecimal-colon notation, such as 2001:db8:ccc3:ffff:0:444d:555e:666f. You can also specify null to connect to the host server on which the SWF file resides. If the SWF file issuing this call is running in a web browser, host must be in the domain from which the SWF file originated.

port

The TCP port number on the target host used to establish a connection. In Flash Player 9.0.124.0 and later, the target host must serve a socket policy file specifying that socket connections are permitted from the host serving the SWF file to the specified port. In earlier versions of Flash Player, a socket policy file is required only if you want to connect to a port number below 1024, or if you want to connect to a host other than the one serving the SWF file.

Throws:

SecurityError

This error occurs in SWF content for the following reasons: Local-with-filesystem files cannot communicate with the Internet. You can work around this problem by reclassifying this SWF file as local-with-networking or trusted. This limitation is not set for AIR application content in the application security sandbox. You cannot specify a socket port higher than 65535.

Variables

read onlybytesAvailable:Int

The number of bytes of data available for reading in the input buffer.

Your code must access bytesAvailable to ensure that sufficient data is available before trying to read it with one of the read methods.

read onlybytesPending:Int

Indicates the number of bytes remaining in the write buffer.

Use this property in combination with with the OutputProgressEvent. An OutputProgressEvent is thrown whenever data is written from the write buffer to the network. In the event handler, you can check bytesPending to see how much data is still left in the buffer waiting to be written. When bytesPending returns 0, it means that all the data has been transferred from the write buffer to the network, and it is safe to do things like remove event handlers, null out socket references, start the next upload in a queue, etc.

read onlyconnected:Bool

Indicates whether this Socket object is currently connected. A call to this property returns a value of true if the socket is currently connected, or false otherwise.

endian:Endian

Indicates the byte order for the data. Possible values are constants from the openfl.utils.Endian class, Endian.BIG_ENDIAN or Endian.LITTLE_ENDIAN.

objectEncoding:ObjectEncoding

Controls the version of AMF used when writing or reading an object.

timeout:Int

Indicates the number of milliseconds to wait for a connection. If the connection doesn't succeed within the specified time, the connection fails. The default value is 20,000 (twenty seconds).

Methods

close ():Void

Closes the socket. You cannot read or write any data after the close() method has been called. The close event is dispatched only when the server closes the connection; it is not dispatched when you call the close() method.

You can reuse the Socket object by calling the connect() method on it again.

Throws:

IOError

The socket could not be closed, or the socket was not open.

connect (?host:String, port:Int = 0):Void

Connects the socket to the specified host and port. If the connection fails immediately, either an event is dispatched or an exception is thrown: an error event is dispatched if a host was specified, and an exception is thrown if no host was specified. Otherwise, the status of the connection is reported by an event. If the socket is already connected, the existing connection is closed first.

@event connect Dispatched when a network connection has been

				 established.

@event ioError Dispatched if a host is specified and an

				 input/output error occurs that causes the
				 connection to fail.

@event securityError Dispatched if a call to Socket.connect()

				 attempts to connect either to a server that
				 doesn't serve a socket policy file, or to a
				 server whose policy file doesn't grant the
				 calling host access to the specified port. For
				 more information on policy files, see "Website
				 controls (policy files)" in the _ActionScript 3.0
				 Developer's Guide_ and the Flash Player Developer
				 Center Topic: <a
				 href="http://www.adobe.com/go/devnet_security_en"
				 scope="external">Security</a>.

Parameters:

host

The name or IP address of the host to connect to. If no host is specified, the host that is contacted is the host where the calling file resides. If you do not specify a host, use an event listener to determine whether the connection was successful.

port

The port number to connect to.

Throws:

IOError

No host was specified and the connection failed.

SecurityError

This error occurs in SWF content for the following reasons: Local untrusted SWF files may not communicate with the Internet. You can work around this limitation by reclassifying the file as local-with-networking or as trusted. You cannot specify a socket port higher than 65535. * In the HTML page that contains the SWF content, the allowNetworking parameter of the object and embed tags is set to "none".

flush ():Void

Flushes any accumulated data in the socket's output buffer. On some operating systems, flush() is called automatically between execution frames, but on other operating systems, such as Windows, the data is never sent unless you call flush() explicitly. To ensure your application behaves reliably across all operating systems, it is a good practice to call the flush() method after writing each message (or related group of data) to the socket.

Throws:

IOError

An I/O error occurred on the socket, or the socket is not open.

readBoolean ():Bool

Reads a Boolean value from the socket. After reading a single byte, the method returns true if the byte is nonzero, and false otherwise.

Throws:

EOFError

There is insufficient data available to read.

IOError

An I/O error occurred on the socket, or the socket is not open.

Returns:

A value of true if the byte read is nonzero, otherwise false.

readByte ():Int

Reads a signed byte from the socket.

Throws:

EOFError

There is insufficient data available to read.

IOError

An I/O error occurred on the socket, or the socket is not open.

Returns:

A value from -128 to 127.

readBytes (bytes:ByteArray, offset:Int = 0, length:Int = 0):Void

Reads the number of data bytes specified by the length parameter from the socket. The bytes are read into the specified byte array, starting at the position indicated by offset.

Parameters:

bytes

The ByteArray object to read data into.

offset

The offset at which data reading should begin in the byte array.

length

The number of bytes to read. The default value of 0 causes all available data to be read.

Throws:

EOFError

There is insufficient data available to read.

IOError

An I/O error occurred on the socket, or the socket is not open.

readDouble ():Float

Reads an IEEE 754 double-precision floating-point number from the socket.

Throws:

EOFError

There is insufficient data available to read.

IOError

An I/O error occurred on the socket, or the socket is not open.

Returns:

An IEEE 754 double-precision floating-point number.

readFloat ():Float

Reads an IEEE 754 single-precision floating-point number from the socket.

Throws:

EOFError

There is insufficient data available to read.

IOError

An I/O error occurred on the socket, or the socket is not open.

Returns:

An IEEE 754 single-precision floating-point number.

readInt ():Int

Reads a signed 32-bit integer from the socket.

Throws:

EOFError

There is insufficient data available to read.

IOError

An I/O error occurred on the socket, or the socket is not open.

Returns:

A value from -2147483648 to 2147483647.

readMultiByte (length:Int, charSet:String):String

Reads a multibyte string from the byte stream, using the specified character set.

Parameters:

length

The number of bytes from the byte stream to read.

charSet

The string denoting the character set to use to interpret the bytes. Possible character set strings include "shift_jis", "CN-GB", and "iso-8859-1". For a complete list, see <a href="../../charset-codes.html">Supported Character Sets. Note: If the value for the charSet parameter is not recognized by the current system, then the application uses the system's default code page as the character set. For example, a value for the charSet parameter, as in myTest.readMultiByte(22, "iso-8859-01") that uses 01 instead of 1 might work on your development machine, but not on another machine. On the other machine, the application will use the system's default code page.

Throws:

EOFError

There is insufficient data available to read.

Returns:

A UTF-8 encoded string.

readObject ():Dynamic

Reads an object from the socket, encoded in AMF serialized format.

Throws:

EOFError

There is insufficient data available to read.

IOError

An I/O error occurred on the socket, or the socket is not open.

Returns:

The deserialized object

readShort ():Int

Reads a signed 16-bit integer from the socket.

Throws:

EOFError

There is insufficient data available to read.

IOError

An I/O error occurred on the socket, or the socket is not open.

Returns:

A value from -32768 to 32767.

readUTF ():String

Reads a UTF-8 string from the socket. The string is assumed to be prefixed with an unsigned short integer that indicates the length in bytes.

Throws:

EOFError

There is insufficient data available to read.

IOError

An I/O error occurred on the socket, or the socket is not open.

Returns:

A UTF-8 string.

readUTFBytes (length:Int):String

Reads the number of UTF-8 data bytes specified by the length parameter from the socket, and returns a string.

Parameters:

length

The number of bytes to read.

Throws:

EOFError

There is insufficient data available to read.

IOError

An I/O error occurred on the socket, or the socket is not open.

Returns:

A UTF-8 string.

readUnsignedByte ():Int

Reads an unsigned byte from the socket.

Throws:

EOFError

There is insufficient data available to read.

IOError

An I/O error occurred on the socket, or the socket is not open.

Returns:

A value from 0 to 255.

readUnsignedInt ():Int

Reads an unsigned 32-bit integer from the socket.

Throws:

EOFError

There is insufficient data available to read.

IOError

An I/O error occurred on the socket, or the socket is not open.

Returns:

A value from 0 to 4294967295.

readUnsignedShort ():Int

Reads an unsigned 16-bit integer from the socket.

Throws:

EOFError

There is insufficient data available to read.

IOError

An I/O error occurred on the socket, or the socket is not open.

Returns:

A value from 0 to 65535.

writeBoolean (value:Bool):Void

Writes a Boolean value to the socket. This method writes a single byte, with either a value of 1 (true) or 0 (false).

Parameters:

value

The value to write to the socket: 1 (true) or 0 (false).

Throws:

IOError

An I/O error occurred on the socket, or the socket is not open.

writeByte (value:Int):Void

Writes a byte to the socket.

Parameters:

value

The value to write to the socket. The low 8 bits of the value are used; the high 24 bits are ignored.

Throws:

IOError

An I/O error occurred on the socket, or the socket is not open.

writeBytes (bytes:ByteArray, offset:Int = 0, length:Int = 0):Void

Writes a sequence of bytes from the specified byte array. The write operation starts at the position specified by offset. If you omit the length parameter the default length of 0 causes the method to write the entire buffer starting at offset.

If you also omit the offset parameter, the entire buffer is written.

Parameters:

bytes

The ByteArray object to write data from.

offset

The zero-based offset into the bytes ByteArray object at which data writing should begin.

length

The number of bytes to write. The default value of 0 causes the entire buffer to be written, starting at the value specified by the offset parameter.

Throws:

IOError

An I/O error occurred on the socket, or the socket is not open.

RangeError

If offset is greater than the length of the ByteArray specified in bytes or if the amount of data specified to be written by offset plus length exceeds the data available.

writeDouble (value:Float):Void

Writes an IEEE 754 double-precision floating-point number to the socket.

Parameters:

value

The value to write to the socket.

Throws:

IOError

An I/O error occurred on the socket, or the socket is not open.

writeFloat (value:Float):Void

Writes an IEEE 754 single-precision floating-point number to the socket.

Parameters:

value

The value to write to the socket.

Throws:

IOError

An I/O error occurred on the socket, or the socket is not open.

writeInt (value:Int):Void

Writes a 32-bit signed integer to the socket.

Parameters:

value

The value to write to the socket.

Throws:

IOError

An I/O error occurred on the socket, or the socket is not open.

writeMultiByte (value:String, charSet:String):Void

Writes a multibyte string from the byte stream, using the specified character set.

Parameters:

value

The string value to be written.

charSet

The string denoting the character set to use to interpret the bytes. Possible character set strings include "shift_jis", "CN-GB", and "iso-8859-1". For a complete list, see <a href="../../charset-codes.html">Supported Character Sets.

writeObject (object:Dynamic):Void

Write an object to the socket in AMF serialized format.

Parameters:

object

The object to be serialized.

Throws:

IOError

An I/O error occurred on the socket, or the socket is not open.

writeShort (value:Int):Void

Writes a 16-bit integer to the socket. The bytes written are as follows:

(v >> 8) & 0xff v & 0xff

The low 16 bits of the parameter are used; the high 16 bits are ignored.

Parameters:

value

The value to write to the socket.

Throws:

IOError

An I/O error occurred on the socket, or the socket is not open.

writeUTF (value:String):Void

Writes the following data to the socket: a 16-bit unsigned integer, which indicates the length of the specified UTF-8 string in bytes, followed by the string itself. Before writing the string, the method calculates the number of bytes that are needed to represent all characters of the string.

Parameters:

value

The string to write to the socket.

Throws:

IOError

An I/O error occurred on the socket, or the socket is not open.

RangeError

The length is larger than 65535.

writeUTFBytes (value:String):Void

Writes a UTF-8 string to the socket.

Parameters:

value

The string to write to the socket.

Throws:

IOError

An I/O error occurred on the socket, or the socket is not open.

writeUnsignedInt (value:Int):Void

Writes a 32-bit unsigned integer to the socket.

Parameters:

value

The value to write to the socket.

Throws:

IOError

An I/O error occurred on the socket, or the socket is not open.

Inherited Variables

Inherited Methods

Defined by EventDispatcher

addEventListener<T> (type:EventType<T>, listener:T ‑> Void, useCapture:Bool = false, priority:Int = 0, useWeakReference:Bool = false):Void

Registers an event listener object with an EventDispatcher object so that the listener receives notification of an event. You can register event listeners on all nodes in the display list for a specific type of event, phase, and priority.

After you successfully register an event listener, you cannot change its priority through additional calls to addEventListener(). To change a listener's priority, you must first call removeListener(). Then you can register the listener again with the new priority level.

Keep in mind that after the listener is registered, subsequent calls to addEventListener() with a different type or useCapture value result in the creation of a separate listener registration. For example, if you first register a listener with useCapture set to true, it listens only during the capture phase. If you call addEventListener() again using the same listener object, but with useCapture set to false, you have two separate listeners: one that listens during the capture phase and another that listens during the target and bubbling phases.

You cannot register an event listener for only the target phase or the bubbling phase. Those phases are coupled during registration because bubbling applies only to the ancestors of the target node.

If you no longer need an event listener, remove it by calling removeEventListener(), or memory problems could result. Event listeners are not automatically removed from memory because the garbage collector does not remove the listener as long as the dispatching object exists(unless the useWeakReference parameter is set to true).

Copying an EventDispatcher instance does not copy the event listeners attached to it.(If your newly created node needs an event listener, you must attach the listener after creating the node.) However, if you move an EventDispatcher instance, the event listeners attached to it move along with it.

If the event listener is being registered on a node while an event is being processed on this node, the event listener is not triggered during the current phase but can be triggered during a later phase in the event flow, such as the bubbling phase.

If an event listener is removed from a node while an event is being processed on the node, it is still triggered by the current actions. After it is removed, the event listener is never invoked again(unless registered again for future processing).

Parameters:

type

The type of event.

useCapture

Determines whether the listener works in the capture phase or the target and bubbling phases. If useCapture is set to true, the listener processes the event only during the capture phase and not in the target or bubbling phase. If useCapture is false, the listener processes the event only during the target or bubbling phase. To listen for the event in all three phases, call addEventListener twice, once with useCapture set to true, then again with useCapture set to false.

priority

The priority level of the event listener. The priority is designated by a signed 32-bit integer. The higher the number, the higher the priority. All listeners with priority n are processed before listeners of priority n-1. If two or more listeners share the same priority, they are processed in the order in which they were added. The default priority is 0.

useWeakReference

Determines whether the reference to the listener is strong or weak. A strong reference(the default) prevents your listener from being garbage-collected. A weak reference does not.

Class-level member functions are not subject to garbage collection, so you can set useWeakReference to true for class-level member functions without subjecting them to garbage collection. If you set useWeakReference to true for a listener that is a nested inner function, the function will be garbage-collected and no longer persistent. If you create references to the inner function(save it in another variable) then it is not garbage-collected and stays persistent.

Throws:

ArgumentError

The listener specified is not a function.

dispatchEvent (event:Event):Bool

Dispatches an event into the event flow. The event target is the EventDispatcher object upon which the dispatchEvent() method is called.

Parameters:

event

The Event object that is dispatched into the event flow. If the event is being redispatched, a clone of the event is created automatically. After an event is dispatched, its target property cannot be changed, so you must create a new copy of the event for redispatching to work.

Throws:

Error

The event dispatch recursion limit has been reached.

Returns:

A value of true if the event was successfully dispatched. A value of false indicates failure or that preventDefault() was called on the event.

hasEventListener (type:String):Bool

Checks whether the EventDispatcher object has any listeners registered for a specific type of event. This allows you to determine where an EventDispatcher object has altered handling of an event type in the event flow hierarchy. To determine whether a specific event type actually triggers an event listener, use willTrigger().

The difference between hasEventListener() and willTrigger() is that hasEventListener() examines only the object to which it belongs, whereas willTrigger() examines the entire event flow for the event specified by the type parameter.

When hasEventListener() is called from a LoaderInfo object, only the listeners that the caller can access are considered.

Parameters:

type

The type of event.

Returns:

A value of true if a listener of the specified type is registered; false otherwise.

removeEventListener<T> (type:EventType<T>, listener:T ‑> Void, useCapture:Bool = false):Void

Removes a listener from the EventDispatcher object. If there is no matching listener registered with the EventDispatcher object, a call to this method has no effect.

Parameters:

type

The type of event.

useCapture

Specifies whether the listener was registered for the capture phase or the target and bubbling phases. If the listener was registered for both the capture phase and the target and bubbling phases, two calls to removeEventListener() are required to remove both, one call with useCapture() set to true, and another call with useCapture() set to false.

toString ():String

willTrigger (type:String):Bool

Checks whether an event listener is registered with this EventDispatcher object or any of its ancestors for the specified event type. This method returns true if an event listener is triggered during any phase of the event flow when an event of the specified type is dispatched to this EventDispatcher object or any of its descendants.

The difference between the hasEventListener() and the willTrigger() methods is that hasEventListener() examines only the object to which it belongs, whereas the willTrigger() method examines the entire event flow for the event specified by the type parameter.

When willTrigger() is called from a LoaderInfo object, only the listeners that the caller can access are considered.

Parameters:

type

The type of event.

Returns:

A value of true if a listener of the specified type will be triggered; false otherwise.