flash.utils.IDataOutput - Adobe® Flex® 4 Language Reference (Flex 4)

Package	flash.utils
Interface	public interface IDataOutput
Implementors	ByteArray, FileStream, Socket

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9, Flash Lite 4

The IDataOutput interface provides a set of methods for writing binary data. This interface is the I/O counterpart to the IDataInput interface, which reads binary data. The IDataOutput interface is implemented by the FileStream, Socket and ByteArray classes.

All IDataInput and IDataOutput operations are "bigEndian" by default (the most significant byte in the sequence is stored at the lowest or first storage address), and are nonblocking.

Sign extension matters only when you read data, not when you write it. Therefore, you do not need separate write methods to work with IDataInput.readUnsignedByte() and IDataInput.readUnsignedShort(). In other words:

Use IDataOutput.writeByte() with IDataInput.readUnsignedByte() and IDataInput.readByte().
Use IDataOutput.writeShort() with IDataInput.readUnsignedShort() and IDataInput.readShort().

View the examples

Public Properties

	Property		Defined By
		endian : String The byte order for the data, either the BIG_ENDIAN or LITTLE_ENDIAN constant from the Endian class.	IDataOutput
		objectEncoding : uint Used to determine whether the AMF3 or AMF0 format is used when writing or reading binary data using the writeObject() method.	IDataOutput

Public Methods

	Method		Defined By
		writeBoolean(value:Boolean):void Writes a Boolean value.	IDataOutput
		writeByte(value:int):void Writes a byte.	IDataOutput
		writeBytes(bytes:ByteArray, offset:uint = 0, length:uint = 0):void Writes a sequence of bytes from the specified byte array, bytes, starting at the byte specified by offset (using a zero-based index) with a length specified by length, into the file stream, byte stream, or byte array.	IDataOutput
		writeDouble(value:Number):void Writes an IEEE 754 double-precision (64-bit) floating point number.	IDataOutput
		writeFloat(value:Number):void Writes an IEEE 754 single-precision (32-bit) floating point number.	IDataOutput
		writeInt(value:int):void Writes a 32-bit signed integer.	IDataOutput
		writeMultiByte(value:String, charSet:String):void Writes a multibyte string to the file stream, byte stream, or byte array, using the specified character set.	IDataOutput
		writeObject(object:*):void Writes an object to the file stream, byte stream, or byte array, in AMF serialized format.	IDataOutput
		writeShort(value:int):void Writes a 16-bit integer.	IDataOutput
		writeUnsignedInt(value:uint):void Writes a 32-bit unsigned integer.	IDataOutput
		writeUTF(value:String):void Writes a UTF-8 string to the file stream, byte stream, or byte array.	IDataOutput
		writeUTFBytes(value:String):void Writes a UTF-8 string.	IDataOutput

Property Detail

endian

property

endian:String

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9, Flash Lite 4

The byte order for the data, either the BIG_ENDIAN or LITTLE_ENDIAN constant from the Endian class.

Implementation
public function get endian():String
public function set endian(value:String):void

See also

Endian class

objectEncoding

property

objectEncoding:uint

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9, Flash Lite 4

Used to determine whether the AMF3 or AMF0 format is used when writing or reading binary data using the writeObject() method. The value is a constant from the ObjectEncoding class.

Implementation
public function get objectEncoding():uint
public function set objectEncoding(value:uint):void

Method Detail

writeBoolean

()

method

public function writeBoolean(value:Boolean):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9, Flash Lite 4

Writes a Boolean value. A single byte is written according to the value parameter, either 1 if true or 0 if false.

Parameters

value:Boolean — A Boolean value determining which byte is written. If the parameter is true, 1 is written; if false, 0 is written.

writeByte

()

method

public function writeByte(value:int):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9, Flash Lite 4

Writes a byte. The low 8 bits of the parameter are used; the high 24 bits are ignored.

Parameters

value:int — A byte value as an integer.

writeBytes

()

method

public function writeBytes(bytes:ByteArray, offset:uint = 0, length:uint = 0):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9, Flash Lite 4

Writes a sequence of bytes from the specified byte array, bytes, starting at the byte specified by offset (using a zero-based index) with a length specified by length, into the file stream, byte stream, or byte array.

If the length parameter is omitted, the default length of 0 is used and the entire buffer starting at offset is written. If the offset parameter is also omitted, the entire buffer is written.

If the offset or length parameter is out of range, they are clamped to the beginning and end of the bytes array.

Parameters

	`bytes:ByteArray` — The byte array to write.

	`offset:uint` (default = `0`) — A zero-based index specifying the position into the array to begin writing.

	`length:uint` (default = `0`) — An unsigned integer specifying how far into the buffer to write.

writeDouble

()

method

public function writeDouble(value:Number):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9, Flash Lite 4

Writes an IEEE 754 double-precision (64-bit) floating point number.

Parameters

value:Number — A double-precision (64-bit) floating point number.

writeFloat

()

method

public function writeFloat(value:Number):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9, Flash Lite 4

Writes an IEEE 754 single-precision (32-bit) floating point number.

Parameters

value:Number — A single-precision (32-bit) floating point number.

writeInt

()

method

public function writeInt(value:int):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9, Flash Lite 4

Writes a 32-bit signed integer.

Parameters

value:int — A byte value as a signed integer.

writeMultiByte

()

method

public function writeMultiByte(value:String, charSet:String):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9, Flash Lite 4

Writes a multibyte string to the file stream, byte stream, or byte array, using the specified character set.

Parameters

	`value:String` — The string value to be written.

	`charSet:String` — The string denoting the character set to use. Possible character set strings include `"shift-jis"`, `"cn-gb"`, `"iso-8859-1"`, and others. For a complete list, see Supported Character Sets.

writeObject

()

method

public function writeObject(object:*):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9, Flash Lite 4

Writes an object to the file stream, byte stream, or byte array, in AMF serialized format.

Parameters

object:* — The object to be serialized.

writeShort

()

method

public function writeShort(value:int):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9, Flash Lite 4

Writes a 16-bit integer. The low 16 bits of the parameter are used; the high 16 bits are ignored.

Parameters

value:int — A byte value as an integer.

writeUnsignedInt

()

method

public function writeUnsignedInt(value:uint):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9, Flash Lite 4

Writes a 32-bit unsigned integer.

Parameters

value:uint — A byte value as an unsigned integer.

writeUTF

()

method

public function writeUTF(value:String):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9, Flash Lite 4

Writes a UTF-8 string to the file stream, byte stream, or byte array. The length of the UTF-8 string in bytes is written first, as a 16-bit integer, followed by the bytes representing the characters of the string.

Parameters

value:String — The string value to be written.

Throws

RangeError — If the length is larger than 65535.

writeUTFBytes

()

method

public function writeUTFBytes(value:String):void

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9, Flash Lite 4

Writes a UTF-8 string. Similar to writeUTF(), but does not prefix the string with a 16-bit length word.

Parameters

value:String — The string value to be written.

Examples How to use this example

DataOutputExample.as

The following example uses the class DataOutputExample to write a boolean and the double-precision floating-point representation of pi to a byte array. This is accomplished using the following steps:

Declare a new ByteArray object instance byteArr.
Write the byte-equivalent value of the Boolean false and the double-precision floating-point equivalent of the mathematical value of pi.
Read back the boolean and double-precision floating-point number.

Notice how a code segment is added at the end to check for end of file errors to ensure that the byte stream is not read past its end.

package {
    import flash.display.Sprite;
    import flash.utils.ByteArray;
    import flash.errors.EOFError;

    public class DataOutputExample extends Sprite {        
        public function DataOutputExample() {
            var byteArr:ByteArray = new ByteArray();

            byteArr.writeBoolean(false);
            byteArr.writeDouble(Math.PI);
            
            byteArr.position = 0;

            try {
                trace(byteArr.readBoolean()); // false
            } 
            catch(e:EOFError) {
                trace(e);           // EOFError: Error #2030: End of file was encountered.
            }
                        
            try {
                trace(byteArr.readDouble());    // 3.141592653589793
            } 
            catch(e:EOFError) {
                trace(e);           // EOFError: Error #2030: End of file was encountered.
            }
            
            try {
                trace(byteArr.readDouble());
            } 
            catch(e:EOFError) {
                trace(e);        // EOFError: Error #2030: End of file was encountered.
            }
        }
    }
}