CkoGzip Objective-C Reference Documentation

CkoGzip

Current Version: 9.5.0.97

GZip compression component.

Object Creation

CkoGzip *obj = [[CkoGzip alloc] init];

Properties

AbortCurrent
@property (nonatomic) BOOL AbortCurrent;
Introduced in version 9.5.0.58

When set to YES, causes the currently running method to abort. Methods that always finish quickly (i.e.have no length file operations or network communications) are not affected. If no method is running, then this property is automatically reset to NO when the next method is called. When the abort occurs, this property is reset to NO. Both synchronous and asynchronous method calls can be aborted. (A synchronous method call could be aborted by setting this property from a separate thread.)

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Comment
@property (nonatomic, copy) NSString *Comment;

Specifies an optional comment string that can be embedded within the .gz when any Compress* method is called.

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CompressionLevel
@property (nonatomic, copy) NSNumber *CompressionLevel;
Introduced in version 9.5.0.50

The compression level to be used when compressing. The default is 6, which is the typical value used for zip utility programs when compressing data. The compression level may range from 0 (no compression) to 9 (the most compression). The benefits of trying to increase compression may not be worth the added expense in compression time. In many cases (which is data dependent), the improvement in compression is minimal while the increase in computation time is significant.

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DebugLogFilePath
@property (nonatomic, copy) NSString *DebugLogFilePath;

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.

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ExtraData
@property (nonatomic, copy) NSData *ExtraData;

Optional extra-data that can be included within a .gz when a Compress* method is called.

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Filename
@property (nonatomic, copy) NSString *Filename;

The filename that is embedded within the .gz during any Compress* method call. When extracting from a .gz using applications such as WinZip, this will be the filename that is created.

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HeartbeatMs
@property (nonatomic, copy) NSNumber *HeartbeatMs;

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
@property (nonatomic, readonly, copy) NSString *LastErrorHtml;

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
@property (nonatomic, readonly, copy) NSString *LastErrorText;

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
@property (nonatomic, readonly, copy) NSString *LastErrorXml;

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
@property (nonatomic) BOOL LastMethodSuccess;

Indicate whether the last method call succeeded or failed. A value of YES indicates success, a value of NO 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 = YES and failure = NO.
  • 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 YES. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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LastModStr
@property (nonatomic, copy) NSString *LastModStr;

The same as the LastMod property, but allows the date/time to be get/set in RFC822 string format.

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UseCurrentDate
@property (nonatomic) BOOL UseCurrentDate;

If set to YES, the file produced by an Uncompress* method will use the current date/time for the last-modification date instead of the date/time found within the Gzip format.

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VerboseLogging
@property (nonatomic) BOOL VerboseLogging;

If set to YES, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is NO. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
@property (nonatomic, readonly, copy) NSString *Version;

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

More Information and Examples
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Methods

CompressBd
- (BOOL)CompressBd:(CkoBinData *)binDat;
Introduced in version 9.5.0.67

In-place gzip the contents of binDat.

Returns YES for success, NO for failure.

More Information and Examples
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CompressBdAsync (1)
- (CkoTask *)CompressBdAsync:(CkoBinData *)binDat;
Introduced in version 9.5.0.67

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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CompressFile
- (BOOL)CompressFile:(NSString *)srcPath
    destPath:(NSString *)destPath;

Compresses a file to create a GZip compressed file (.gz).

Returns YES for success, NO for failure.

More Information and Examples
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CompressFileAsync (1)
- (CkoTask *)CompressFileAsync:(NSString *)srcPath
    destPath:(NSString *)destPath;

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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CompressFile2
- (BOOL)CompressFile2:(NSString *)srcPath
    embeddedFilename:(NSString *)embeddedFilename
    destPath:(NSString *)destPath;

Compresses a file to create a GZip compressed file (.gz). inFilename is the actual filename on disk. embeddedFilename is the filename to be embedded in the .gz such that when it is un-gzipped, this is the name of the file that will be created.

Returns YES for success, NO for failure.

More Information and Examples
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CompressFile2Async (1)
- (CkoTask *)CompressFile2Async:(NSString *)srcPath
    embeddedFilename:(NSString *)embeddedFilename
    destPath:(NSString *)destPath;

Creates an asynchronous task to call the CompressFile2 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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CompressFileToMem
- (NSData *)CompressFileToMem:(NSString *)srcPath;

Gzip compresses a file to an in-memory image of a .gz file.

Note: There is a 4GB size limitation. The compressed size of the file cannot be more than 4GB. Chilkat will be working to alleviate this limitation in the future.

Returns nil on failure

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CompressFileToMemAsync (1)
- (CkoTask *)CompressFileToMemAsync:(NSString *)srcPath;

Creates an asynchronous task to call the CompressFileToMem 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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CompressMemory
- (NSData *)CompressMemory:(NSData *)dbIn;

Compresses in-memory data to an in-memory image of a .gz file.

Note: There is a 4GB uncompressed size limitation. The uncompressed size of the file cannot be more than 4GB. Chilkat will be working to alleviate this limitation in the future.

Returns nil on failure

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CompressMemoryAsync (1)
- (CkoTask *)CompressMemoryAsync:(NSData *)dbIn;

Creates an asynchronous task to call the CompressMemory 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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CompressMemToFile
- (BOOL)CompressMemToFile:(NSData *)db
    destPath:(NSString *)destPath;

Gzip compresses and creates a .gz file from in-memory data.

Returns YES for success, NO for failure.

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CompressMemToFileAsync (1)
- (CkoTask *)CompressMemToFileAsync:(NSData *)db
    destPath:(NSString *)destPath;

Creates an asynchronous task to call the CompressMemToFile 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
- (NSData *)CompressString:(NSString *)inStr
    destCharset:(NSString *)destCharset;

Gzip compresses a string and writes the output to a byte array. The string is first converted to the charset specified by destCharset. Typical charsets are "utf-8", "iso-8859-1", "shift_JIS", etc.

Returns nil on failure

More Information and Examples
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CompressStringAsync (1)
- (CkoTask *)CompressStringAsync:(NSString *)inStr
    destCharset:(NSString *)destCharset;

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
- (NSString *)CompressStringENC:(NSString *)strIn
    charset:(NSString *)charset
    encoding:(NSString *)encoding;

The same as CompressString, except the binary output is returned in encoded string form according to the encoding. The encoding can be any of the following: "Base64", "modBase64", "Base32", "UU", "QP" (for quoted-printable), "URL" (for url-encoding), "Hex", "Q", "B", "url_oath", "url_rfc1738", "url_rfc2396", and "url_rfc3986".

Returns nil on failure

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CompressStringToFile
- (BOOL)CompressStringToFile:(NSString *)inStr
    destCharset:(NSString *)destCharset
    destPath:(NSString *)destPath;

Gzip compresses a string and writes the output to a .gz compressed file. The string is first converted to the charset specified by destCharset. Typical charsets are "utf-8", "iso-8859-1", "shift_JIS", etc.

Returns YES for success, NO for failure.

More Information and Examples
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CompressStringToFileAsync (1)
- (CkoTask *)CompressStringToFileAsync:(NSString *)inStr
    destCharset:(NSString *)destCharset
    destPath:(NSString *)destPath;

Creates an asynchronous task to call the CompressStringToFile 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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Decode
- (NSData *)Decode:(NSString *)str
    encoding:(NSString *)encoding;

Decodes an encoded string and returns the original data. The encoding mode is determined by encoding. It may be "base64", "hex", "quoted-printable", or "url".

Returns nil on failure

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DeflateStringENC
- (NSString *)DeflateStringENC:(NSString *)str
    charset:(NSString *)charset
    encoding:(NSString *)encoding;

Provides the ability to use the zip/gzip's deflate algorithm directly to compress a string. Internal to this method, inString is first converted to the charset specified by charsetName. The data is then compressed using the deflate compression algorithm. The binary output is then encoded according to outputEncoding. Possible values for outputEncoding are "hex", "base64", "url", and "quoted-printable".

Note: The output of this method is compressed data with no Gzip file format. Use the Compress* methods to produce Gzip file format output.

Returns nil on failure

More Information and Examples
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Encode
- (NSString *)Encode:(NSData *)byteData
    encoding:(NSString *)encoding;

Encodes binary data to a printable string. The encoding mode is determined by encoding. It may be "base64", "hex", "quoted-printable", or "url".

Returns nil on failure

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ExamineFile
- (BOOL)ExamineFile:(NSString *)inGzPath;

Determines if the inGzFilename is a Gzip formatted file. Returns YES if it is a Gzip formatted file, otherwise returns NO.

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ExamineMemory
- (BOOL)ExamineMemory:(NSData *)inGzData;

Determines if the in-memory bytes (inGzData) contain a Gzip formatted file. Returns YES if it is Gzip format, otherwise returns NO.

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GetDt
- (CkoDateTime *)GetDt;

Gets the last-modification date/time to be embedded within the .gz.

Returns nil on failure

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InflateStringENC
- (NSString *)InflateStringENC:(NSString *)str
    charset:(NSString *)charset
    encoding:(NSString *)encoding;

This the reverse of DeflateStringENC.

The input string is first decoded according to inputEncoding. (Possible values for inputEncoding are "hex", "base64", "url", and "quoted-printable".) The compressed data is then inflated, and the result is then converted from convertFromCharset (if necessary) to return a string.

Returns nil on failure

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LoadTaskCaller
- (BOOL)LoadTaskCaller:(CkoTask *)task;
Introduced in version 9.5.0.80

Loads the caller of the task's async method.

Returns YES for success, NO for failure.

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ReadFile
- (NSData *)ReadFile:(NSString *)path;

Reads a binary file into memory and returns the byte array. Note: This method does not parse a Gzip, it is only a convenience method for reading a binary file into memory.

Returns nil on failure

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SetDt
- (BOOL)SetDt:(CkoDateTime *)dt;

Sets the last-modification date/time to be embedded within the .gz when a Compress* method is called. If not explicitly set, the current system date/time is used.

Returns YES for success, NO for failure.

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UncompressBd
- (BOOL)UncompressBd:(CkoBinData *)binDat;
Introduced in version 9.5.0.67

In-place ungzip the contents of binDat.

Returns YES for success, NO for failure.

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UncompressBdAsync (1)
- (CkoTask *)UncompressBdAsync:(CkoBinData *)binDat;
Introduced in version 9.5.0.67

Creates an asynchronous task to call the UncompressBd 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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UncompressFile
- (BOOL)UncompressFile:(NSString *)srcPath
    destPath:(NSString *)destPath;

Un-Gzips a .gz file. The output filename is specified by the 2nd argument and not by the filename embedded within the .gz.

Returns YES for success, NO for failure.

More Information and Examples
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UncompressFileAsync (1)
- (CkoTask *)UncompressFileAsync:(NSString *)srcPath
    destPath:(NSString *)destPath;

Creates an asynchronous task to call the UncompressFile 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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UncompressFileToMem
- (NSData *)UncompressFileToMem:(NSString *)srcPath;

Un-Gzips a .gz file directly to memory.

Note: There is a 4GB uncompressed size limitation. The uncompressed size of the file cannot be more than 4GB. Chilkat will be working to alleviate this limitation in the future.

Returns nil on failure

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UncompressFileToMemAsync (1)
- (CkoTask *)UncompressFileToMemAsync:(NSString *)srcPath;

Creates an asynchronous task to call the UncompressFileToMem 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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UncompressFileToString
- (NSString *)UncompressFileToString:(NSString *)srcPath
    inCharset:(NSString *)inCharset;

Uncompresses a .gz file that contains a text file. The contents of the text file are returned as a string. The character encoding of the text file is specified by charset. Typical charsets are "iso-8859-1", "utf-8", "windows-1252", "shift_JIS", "big5", etc.

Returns nil on failure

More Information and Examples
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UncompressFileToStringAsync (1)
- (CkoTask *)UncompressFileToStringAsync:(NSString *)srcPath
    inCharset:(NSString *)inCharset;

Creates an asynchronous task to call the UncompressFileToString 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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UncompressMemory
- (NSData *)UncompressMemory:(NSData *)dbIn;

Un-Gzips from an in-memory image of a .gz file directly into memory.

Note: There is a 4GB uncompressed size limitation. The uncompressed size of the file cannot be more than 4GB. Chilkat will be working to alleviate this limitation in the future.

Returns nil on failure

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UncompressMemoryAsync (1)
- (CkoTask *)UncompressMemoryAsync:(NSData *)dbIn;

Creates an asynchronous task to call the UncompressMemory 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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UncompressMemToFile
- (BOOL)UncompressMemToFile:(NSData *)db
    destPath:(NSString *)destPath;

Un-Gzips from an in-memory image of a .gz file to a file.

Returns YES for success, NO for failure.

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UncompressMemToFileAsync (1)
- (CkoTask *)UncompressMemToFileAsync:(NSData *)db
    destPath:(NSString *)destPath;

Creates an asynchronous task to call the UncompressMemToFile 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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UncompressString
- (NSString *)UncompressString:(NSData *)inData
    inCharset:(NSString *)inCharset;

The reverse of CompressString.

The bytes in inData are uncompressed, then converted from inCharset (if necessary) to return a string.

Returns nil on failure

More Information and Examples
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UncompressStringAsync (1)
- (CkoTask *)UncompressStringAsync:(NSData *)inData
    inCharset:(NSString *)inCharset;

Creates an asynchronous task to call the UncompressString 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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UncompressStringENC
- (NSString *)UncompressStringENC:(NSString *)strIn
    charset:(NSString *)charset
    encoding:(NSString *)encoding;

The same as UncompressString, except the compressed data is provided in encoded string form based on the value of encoding. The encoding can be "Base64", "modBase64", "Base32", "UU", "QP" (for quoted-printable), "URL" (for url-encoding), "Hex", "Q", "B", "url_oath", "url_rfc1738", "url_rfc2396", and "url_rfc3986".

Returns nil on failure

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UnTarGz
- (BOOL)UnTarGz:(NSString *)gzPath
    destDir:(NSString *)destDir
    bNoAbsolute:(BOOL)bNoAbsolute;

Unpacks a .tar.gz file. The ungzip and untar occur in streaming mode. There are no temporary files and the memory footprint is constant (and small) while untarring. bNoAbsolute may be YES or NO. A value of YES protects from untarring to absolute paths. (For example, imagine the trouble if the tar contains files with absolute paths beginning with /Windows/system32)

Returns YES for success, NO for failure.

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UnTarGzAsync (1)
- (CkoTask *)UnTarGzAsync:(NSString *)gzPath
    destDir:(NSString *)destDir
    bNoAbsolute:(BOOL)bNoAbsolute;

Creates an asynchronous task to call the UnTarGz 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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WriteFile
- (BOOL)WriteFile:(NSString *)path
    binaryData:(NSData *)binaryData;

A convenience method for writing a binary byte array to a file.

Returns YES for success, NO for failure.

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XfdlToXml
- (NSString *)XfdlToXml:(NSString *)xfdl;

Converts base64-gzip .xfdl data to a decompressed XML string. The xfldData contains the base64 data. This method returns the decoded/decompressed XML string.

Returns nil on failure

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Events

To implement an event callback, your application would define and implement a class that inherits from CkoBaseProgress. Your application can implement methods to override some or all of the default/empty method implementations of the CkoBaseProgress base class.

For example:

  CkoGzip *gzip = [[CkoGzip alloc] init];

  MyGzipProgress *callbackObj = [[MyGzipProgress alloc] init];

  [gzip setEventCallbackObject:callbackObj];

MyGzipProgress interface example:

#import "CkoGzipProgress.h"

@interface MyGzipProgress : CkoBaseProgress {

}

    - (id)init;
    - (void)dealloc;
    - (void)dispose;

    - (void)AbortCheck:(BOOL *)abort;

    - (void)PercentDone:(NSNumber *)pctDone 
        abort:(BOOL *)abort;

    - (void)ProgressInfo:(NSString *)name 
        value:(NSString *)value;

    - (void)TaskCompleted:(CkoTask *)task;

@end
AbortCheck
- (void)AbortCheck:(BOOL *)abort;

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
- (void)PercentDone:(NSNumber *)pctDone
    abort:(BOOL *)abort;

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 YES will cause the method to abort and return a failed status (or whatever return value indicates failure).

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ProgressInfo
- (void)ProgressInfo:(NSString *)name
    value:(NSString *)value;

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
- (void)TaskCompleted:(CkoTask *)task;

Called in the background thread when an asynchronous task completes.

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