Compression Xojo Plugin Reference Documentation

Compression

Current Version: 9.5.0.98

Data compression component implementing the PPMD, Bzip2, Deflate, and LZW compression algorithms. .NET, ActiveX, and C++ implementations provide progress monitoring and abort capabilities. Provides a unified API for all supported compression algorithms.

Object Creation

Dim compression As New Chilkat.Compression

Properties

Algorithm
Algorithm As String

The compression algorithm to be used. Should be set to either "ppmd", "deflate", "zlib", "bzip2", or "lzw".

Note: The PPMD compression algorithm is only available for 32-bit builds. It is not available for 64-bit implementations. Also, this PPMD implementation is the "J" variant.

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Charset
Charset As String

Only applies to methods that compress or decompress strings. This specifies the character encoding that the string should be converted to before compression. Many programming languages use Unicode (2 bytes per char) for representing characters. This property allows for the string to be converted to a 1-byte per char encoding prior to compression.

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DebugLogFilePath
DebugLogFilePath As String

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

More Information and Examples
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DeflateLevel
DeflateLevel As Int32
Introduced in version 9.5.0.73

This property allows for customization of the compression level for the "deflate" and "zlib" compression algoirthms. ("zlib" is just the deflate algorithm with a zlib header.) A value of 0 = no compression, while 9 = maximum compression. The default is 6.

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EncodingMode
EncodingMode As String

Controls the encoding expected by methods ending in "ENC", such as CompressBytesENC. Valid values are "base64", "hex", "url", and "quoted-printable". Compression methods ending in ENC return the binary compressed data as an encoded string using this encoding. Decompress methods expect the input string to be this encoding.

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HeartbeatMs
HeartbeatMs As Int32

The number of milliseconds between each AbortCheck event callback. The AbortCheck callback allows an application to abort any method call prior to completion. If HeartbeatMs is 0 (the default), no AbortCheck event callbacks will fire.

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LastErrorHtml
LastErrorHtml As String (read-only)

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorText
LastErrorText As String (read-only)

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorXml
LastErrorXml As String (read-only)

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastMethodSuccess
LastMethodSuccess As Boolean

Indicate whether the last method call succeeded or failed. A value of True indicates success, a value of False indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = True and failure = False.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to True. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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VerboseLogging
VerboseLogging As Boolean

If set to True, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is False. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
Version As String (read-only)

Version of the component/library, such as "9.5.0.94"

More Information and Examples
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Methods

BeginCompressBytes
Function BeginCompressBytes(data As MemoryBlock) As MemoryBlock

Large amounts of binary byte data may be compressed in chunks by first calling BeginCompressBytes, followed by 0 or more calls to MoreCompressedBytes, and ending with a final call to EndCompressBytes. Each call returns 0 or more bytes of compressed data which may be output to a compressed data stream (such as a file, socket, etc.).

Returns Nil on failure

More Information and Examples
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BeginCompressBytesAsync (1)
Function BeginCompressBytesAsync(data As MemoryBlock) As Chilkat.Task

Creates an asynchronous task to call the BeginCompressBytes method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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BeginCompressBytesENC
Function BeginCompressBytesENC(data As MemoryBlock) As String

Large amounts of binary byte data may be compressed in chunks by first calling BeginCompressBytesENC, followed by 0 or more calls to MoreCompressedBytesENC, and ending with a final call to EndCompressBytesENC. Each call returns 0 or more characters of compressed data (encoded as a string according to the EncodingMode property setting) which may be output to a compressed data stream (such as a file, socket, etc.).

Returns Nil on failure

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BeginCompressBytesENCAsync (1)
Function BeginCompressBytesENCAsync(data As MemoryBlock) As Chilkat.Task

Creates an asynchronous task to call the BeginCompressBytesENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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BeginCompressString
Function BeginCompressString(str As String) As MemoryBlock

Large amounts of string data may be compressed in chunks by first calling BeginCompressString, followed by 0 or more calls to MoreCompressedString, and ending with a final call to EndCompressString. Each call returns 0 or more bytes of compressed data which may be output to a compressed data stream (such as a file, socket, etc.).

Returns Nil on failure

More Information and Examples
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BeginCompressStringAsync (1)
Function BeginCompressStringAsync(str As String) As Chilkat.Task

Creates an asynchronous task to call the BeginCompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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BeginCompressStringENC
Function BeginCompressStringENC(str As String) As String

Large amounts of string data may be compressed in chunks by first calling BeginCompressStringENC, followed by 0 or more calls to MoreCompressedStringENC, and ending with a final call to EndCompressStringENC. Each call returns 0 or more characters of compressed data (encoded as a string according to the EncodingMode property setting) which may be output to a compressed data stream (such as a file, socket, etc.).

Returns Nil on failure

More Information and Examples
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BeginCompressStringENCAsync (1)
Function BeginCompressStringENCAsync(str As String) As Chilkat.Task

Creates an asynchronous task to call the BeginCompressStringENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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BeginDecompressBytes
Function BeginDecompressBytes(data As MemoryBlock) As MemoryBlock

A compressed data stream may be decompressed in chunks by first calling BeginDecompressBytes, followed by 0 or more calls to MoreDecompressedBytes, and ending with a final call to EndDecompressBytes. Each call returns 0 or more bytes of decompressed data.

Returns Nil on failure

More Information and Examples
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BeginDecompressBytesAsync (1)
Function BeginDecompressBytesAsync(data As MemoryBlock) As Chilkat.Task

Creates an asynchronous task to call the BeginDecompressBytes method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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BeginDecompressBytesENC
Function BeginDecompressBytesENC(str As String) As MemoryBlock

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

A compressed data stream may be decompressed in chunks by first calling BeginDecompressBytesENC, followed by 0 or more calls to MoreDecompressedBytesENC, and ending with a final call to EndDecompressBytesENC. Each call returns 0 or more bytes of decompressed data.

Returns Nil on failure

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BeginDecompressBytesENCAsync (1)
Function BeginDecompressBytesENCAsync(str As String) As Chilkat.Task

Creates an asynchronous task to call the BeginDecompressBytesENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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BeginDecompressString
Function BeginDecompressString(data As MemoryBlock) As String

A compressed data stream may be decompressed in chunks by first calling BeginDecompressString, followed by 0 or more calls to MoreDecompressedString, and ending with a final call to EndDecompressString. Each call returns 0 or more characters of decompressed text.

Returns Nil on failure

More Information and Examples
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BeginDecompressStringAsync (1)
Function BeginDecompressStringAsync(data As MemoryBlock) As Chilkat.Task

Creates an asynchronous task to call the BeginDecompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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BeginDecompressStringENC
Function BeginDecompressStringENC(str As String) As String

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

A compressed data stream may be decompressed in chunks by first calling BeginDecompressStringENC, followed by 0 or more calls to MoreDecompressedStringENC, and ending with a final call to EndDecompressStringENC. Each call returns 0 or more characters of decompressed text.

Returns Nil on failure

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BeginDecompressStringENCAsync (1)
Function BeginDecompressStringENCAsync(str As String) As Chilkat.Task

Creates an asynchronous task to call the BeginDecompressStringENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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CompressBd
Function CompressBd(binData As Chilkat.BinData) As Boolean
Introduced in version 9.5.0.66

Compresses the data contained in a BinData object.

Returns True for success, False for failure.

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CompressBdAsync (1)
Function CompressBdAsync(binData As Chilkat.BinData) As Chilkat.Task
Introduced in version 9.5.0.66

Creates an asynchronous task to call the CompressBd method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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CompressBytes
Function CompressBytes(data As MemoryBlock) As MemoryBlock

Compresses byte data.

Returns Nil on failure

More Information and Examples
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CompressBytesAsync (1)
Function CompressBytesAsync(data As MemoryBlock) As Chilkat.Task

Creates an asynchronous task to call the CompressBytes method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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CompressBytesENC
Function CompressBytesENC(data As MemoryBlock) As String

Compresses bytes and returns the compressed data encoded to a string. The encoding (hex, base64, etc.) is determined by the EncodingMode property setting.

Returns Nil on failure

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CompressBytesENCAsync (1)
Function CompressBytesENCAsync(data As MemoryBlock) As Chilkat.Task

Creates an asynchronous task to call the CompressBytesENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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CompressFile
Function CompressFile(srcPath As String, destPath As String) As Boolean

Performs file-to-file compression. Files of any size may be compressed because the file is compressed internally in streaming mode.

Returns True for success, False for failure.

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CompressFileAsync (1)
Function CompressFileAsync(srcPath As String, destPath As String) As Chilkat.Task

Creates an asynchronous task to call the CompressFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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CompressSb
Function CompressSb(sb As Chilkat.StringBuilder, binData As Chilkat.BinData) As Boolean
Introduced in version 9.5.0.73

Compresses the contents of sb and appends the compressed bytes to binData.

Returns True for success, False for failure.

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CompressSbAsync (1)
Function CompressSbAsync(sb As Chilkat.StringBuilder, binData As Chilkat.BinData) As Chilkat.Task
Introduced in version 9.5.0.73

Creates an asynchronous task to call the CompressSb method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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CompressStream
Function CompressStream(strm As Chilkat.Stream) As Boolean
Introduced in version 9.5.0.56

Compresses a stream. Internally, the strm's source is read, compressed, and the compressed data written to the strm's sink. It does this in streaming fashion. Extremely large or even infinite streams can be compressed with stable ungrowing memory usage.

Returns True for success, False for failure.

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CompressStreamAsync (1)
Function CompressStreamAsync(strm As Chilkat.Stream) As Chilkat.Task
Introduced in version 9.5.0.56

Creates an asynchronous task to call the CompressStream method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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CompressString
Function CompressString(str As String) As MemoryBlock

Compresses a string.

Returns Nil on failure

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CompressStringAsync (1)
Function CompressStringAsync(str As String) As Chilkat.Task

Creates an asynchronous task to call the CompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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CompressStringENC
Function CompressStringENC(str As String) As String

Compresses a string and returns the compressed data encoded to a string. The output encoding (hex, base64, etc.) is determined by the EncodingMode property setting.

Returns Nil on failure

More Information and Examples
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CompressStringENCAsync (1)
Function CompressStringENCAsync(str As String) As Chilkat.Task

Creates an asynchronous task to call the CompressStringENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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DecompressBd
Function DecompressBd(binData As Chilkat.BinData) As Boolean
Introduced in version 9.5.0.66

Decompresses the data contained in a BinData object.

Returns True for success, False for failure.

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DecompressBdAsync (1)
Function DecompressBdAsync(binData As Chilkat.BinData) As Chilkat.Task
Introduced in version 9.5.0.66

Creates an asynchronous task to call the DecompressBd method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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DecompressBytes
Function DecompressBytes(data As MemoryBlock) As MemoryBlock

The opposite of CompressBytes.

Returns Nil on failure

More Information and Examples
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DecompressBytesAsync (1)
Function DecompressBytesAsync(data As MemoryBlock) As Chilkat.Task

Creates an asynchronous task to call the DecompressBytes method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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DecompressBytesENC
Function DecompressBytesENC(encodedCompressedData As String) As MemoryBlock

The opposite of CompressBytesENC. encodedCompressedData contains the compressed data as an encoded string (hex, base64, etc) as specified by the EncodingMode property setting.

Returns Nil on failure

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DecompressBytesENCAsync (1)
Function DecompressBytesENCAsync(encodedCompressedData As String) As Chilkat.Task

Creates an asynchronous task to call the DecompressBytesENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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DecompressFile
Function DecompressFile(srcPath As String, destPath As String) As Boolean

Performs file-to-file decompression (the opposite of CompressFile). Internally the file is decompressed in streaming mode which allows files of any size to be decompressed.

Returns True for success, False for failure.

More Information and Examples
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DecompressFileAsync (1)
Function DecompressFileAsync(srcPath As String, destPath As String) As Chilkat.Task

Creates an asynchronous task to call the DecompressFile method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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DecompressSb
Function DecompressSb(binData As Chilkat.BinData, sb As Chilkat.StringBuilder) As Boolean
Introduced in version 9.5.0.73

Decompresses the contents of binData and appends the decompressed string to sb.

Returns True for success, False for failure.

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DecompressSbAsync (1)
Function DecompressSbAsync(binData As Chilkat.BinData, sb As Chilkat.StringBuilder) As Chilkat.Task
Introduced in version 9.5.0.73

Creates an asynchronous task to call the DecompressSb method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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DecompressStream
Function DecompressStream(strm As Chilkat.Stream) As Boolean
Introduced in version 9.5.0.56

Decompresses a stream. Internally, the strm's source is read, decompressed, and the decompressed data written to the strm's sink. It does this in streaming fashion. Extremely large or even infinite streams can be decompressed with stable ungrowing memory usage.

Returns True for success, False for failure.

More Information and Examples
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DecompressStreamAsync (1)
Function DecompressStreamAsync(strm As Chilkat.Stream) As Chilkat.Task
Introduced in version 9.5.0.56

Creates an asynchronous task to call the DecompressStream method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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DecompressString
Function DecompressString(data As MemoryBlock) As String

Takes compressed bytes, decompresses, and returns the resulting string.

Returns Nil on failure

More Information and Examples
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DecompressStringAsync (1)
Function DecompressStringAsync(data As MemoryBlock) As Chilkat.Task

Creates an asynchronous task to call the DecompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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DecompressStringENC
Function DecompressStringENC(encodedCompressedData As String) As String

The opposite of CompressStringENC. encodedCompressedData contains the compressed data as an encoded string (hex, base64, etc) as specified by the EncodingMode property setting.

Returns Nil on failure

More Information and Examples
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DecompressStringENCAsync (1)
Function DecompressStringENCAsync(encodedCompressedData As String) As Chilkat.Task

Creates an asynchronous task to call the DecompressStringENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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EndCompressBytes
Function EndCompressBytes() As MemoryBlock

Must be callled to finalize a compression stream. Returns any remaining (buffered) compressed data.

(See BeginCompressBytes)

Returns Nil on failure

More Information and Examples
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EndCompressBytesAsync (1)
Function EndCompressBytesAsync() As Chilkat.Task

Creates an asynchronous task to call the EndCompressBytes method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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EndCompressBytesENC
Function EndCompressBytesENC() As String

Must be callled to finalize a compression stream. Returns any remaining (buffered) compressed data.

(See BeginCompressBytesENC)

Returns Nil on failure

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EndCompressBytesENCAsync (1)
Function EndCompressBytesENCAsync() As Chilkat.Task

Creates an asynchronous task to call the EndCompressBytesENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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EndCompressString
Function EndCompressString() As MemoryBlock

Must be callled to finalize a compression stream. Returns any remaining (buffered) compressed data.

(See BeginCompressString)

Returns Nil on failure

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EndCompressStringAsync (1)
Function EndCompressStringAsync() As Chilkat.Task

Creates an asynchronous task to call the EndCompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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EndCompressStringENC
Function EndCompressStringENC() As String

Must be callled to finalize a compression stream. Returns any remaining (buffered) compressed data.

(See BeginCompressStringENC)

Returns Nil on failure

More Information and Examples
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EndCompressStringENCAsync (1)
Function EndCompressStringENCAsync() As Chilkat.Task

Creates an asynchronous task to call the EndCompressStringENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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EndDecompressBytes
Function EndDecompressBytes() As MemoryBlock

Called to finalize the decompression stream and return any remaining (buffered) decompressed data.

(See BeginDecompressBytes)

Returns Nil on failure

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EndDecompressBytesAsync (1)
Function EndDecompressBytesAsync() As Chilkat.Task

Creates an asynchronous task to call the EndDecompressBytes method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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EndDecompressBytesENC
Function EndDecompressBytesENC() As MemoryBlock

Called to finalize the decompression stream and return any remaining (buffered) decompressed data.

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

(See BeginDecompressBytesENC)

Returns Nil on failure

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EndDecompressBytesENCAsync (1)
Function EndDecompressBytesENCAsync() As Chilkat.Task

Creates an asynchronous task to call the EndDecompressBytesENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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EndDecompressString
Function EndDecompressString() As String

Called to finalize the decompression stream and return any remaining (buffered) decompressed data.

(See BeginDecompressString)

Returns Nil on failure

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EndDecompressStringAsync (1)
Function EndDecompressStringAsync() As Chilkat.Task

Creates an asynchronous task to call the EndDecompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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EndDecompressStringENC
Function EndDecompressStringENC() As String

Called to finalize the decompression stream and return any remaining (buffered) decompressed data.

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

(See BeginDecompressStringENC)

Returns Nil on failure

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EndDecompressStringENCAsync (1)
Function EndDecompressStringENCAsync() As Chilkat.Task

Creates an asynchronous task to call the EndDecompressStringENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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LoadTaskCaller
Function LoadTaskCaller(task As Chilkat.Task) As Boolean
Introduced in version 9.5.0.80

Loads the caller of the task's async method.

Returns True for success, False for failure.

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MoreCompressBytes
Function MoreCompressBytes(data As MemoryBlock) As MemoryBlock

(See BeginCompressBytes)

Returns Nil on failure

More Information and Examples
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MoreCompressBytesAsync (1)
Function MoreCompressBytesAsync(data As MemoryBlock) As Chilkat.Task

Creates an asynchronous task to call the MoreCompressBytes method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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MoreCompressBytesENC
Function MoreCompressBytesENC(data As MemoryBlock) As String

(See BeginCompressBytesENC)

Returns Nil on failure

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MoreCompressBytesENCAsync (1)
Function MoreCompressBytesENCAsync(data As MemoryBlock) As Chilkat.Task

Creates an asynchronous task to call the MoreCompressBytesENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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MoreCompressString
Function MoreCompressString(str As String) As MemoryBlock

(See BeginCompressString)

Returns Nil on failure

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MoreCompressStringAsync (1)
Function MoreCompressStringAsync(str As String) As Chilkat.Task

Creates an asynchronous task to call the MoreCompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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MoreCompressStringENC
Function MoreCompressStringENC(str As String) As String

(See BeginCompressStringENC)

Returns Nil on failure

More Information and Examples
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MoreCompressStringENCAsync (1)
Function MoreCompressStringENCAsync(str As String) As Chilkat.Task

Creates an asynchronous task to call the MoreCompressStringENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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MoreDecompressBytes
Function MoreDecompressBytes(data As MemoryBlock) As MemoryBlock

(See BeginDecompressBytes)

Returns Nil on failure

More Information and Examples
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MoreDecompressBytesAsync (1)
Function MoreDecompressBytesAsync(data As MemoryBlock) As Chilkat.Task

Creates an asynchronous task to call the MoreDecompressBytes method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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MoreDecompressBytesENC
Function MoreDecompressBytesENC(str As String) As MemoryBlock

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

(See BeginDecompressBytesENC)

Returns Nil on failure

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MoreDecompressBytesENCAsync (1)
Function MoreDecompressBytesENCAsync(str As String) As Chilkat.Task

Creates an asynchronous task to call the MoreDecompressBytesENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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MoreDecompressString
Function MoreDecompressString(data As MemoryBlock) As String

(See BeginDecompressString)

Returns Nil on failure

More Information and Examples
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MoreDecompressStringAsync (1)
Function MoreDecompressStringAsync(data As MemoryBlock) As Chilkat.Task

Creates an asynchronous task to call the MoreDecompressString method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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MoreDecompressStringENC
Function MoreDecompressStringENC(str As String) As String

The input to this method is an encoded string containing compressed data. The EncodingMode property should be set prior to calling this method. The input string is decoded according to the EncodingMode (hex, base64, etc.) and then decompressed.

(See BeginDecompressStringENC)

Returns Nil on failure

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MoreDecompressStringENCAsync (1)
Function MoreDecompressStringENCAsync(str As String) As Chilkat.Task

Creates an asynchronous task to call the MoreDecompressStringENC method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns Nil on failure

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Events

To implement events, your application would define and implement a class that is a subclass of Chilkat.Compression. Your custom class would implement (i.e. override) some or all of the event methods.

For example:

class MyCompression
    Inherits Chilkat.Compression

    Function AbortCheck() As Boolean

    Function PercentDone(pctDone As Int32) As Boolean

    Sub ProgressInfo(name As String, value As String)

    Sub TaskCompleted(task As Chilkat.Task)


End Class
AbortCheck
Function AbortCheck() As Boolean

Provides the opportunity for a method call to be aborted. The AbortCheck event is fired periodically based on the value of the HeartbeatMs property. If HeartbeatMs is 0, then no AbortCheck events will fire. As an example, to fire 5 AbortCheck events per second, set the HeartbeatMs property equal to 200.

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PercentDone
Function PercentDone(pctDone As Int32) As Boolean

Provides the percentage completed for any method that involves network communications or time-consuming processing (assuming it is a method where a percentage completion can be measured). This event is only fired when it is possible to know a percentage completion, and when it makes sense to express the operation as a percentage completed. The pctDone argument will have a value from 1 to 100. For operations (Chilkat method calls) that complete very quickly, the number of PercentDone callbacks will vary, but the final callback should have a value of 100. For long running operations, no more than one callback per percentage point will occur (for example: 1, 2, 3, ... 98, 99, 100).

The PercentDone callback counts as an AbortCheck event. For method calls that complete quickly such that PercentDone events fire, it may be that AbortCheck events don't fire because the opportunity to abort is already provided in the PercentDone callback. For time consuming operations, where the amount of time between PercentDone callbacks are long, AbortCheck callbacks may be used to allow for the operation to be aborted in a more responsive manner.

The abort output argument provides a means for aborting the operation. Setting it to True will cause the method to abort and return a failed status (or whatever return value indicates failure).

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ProgressInfo
Sub ProgressInfo(name As String, value As String)

A general name/value event that provides information about what is happening during a method call. To find out what information is available, write code to handle this event and log the name/value pairs. Most are self-explanatory.

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TaskCompleted
Sub TaskCompleted(task As Chilkat.Task)

Called in the background thread when an asynchronous task completes.

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