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IPWorks ZIP 2022 JavaScript Edition

Version 22.0 [Build 8203]

ZCompress Class

Properties   Methods   Events   Configuration Settings   Errors  

The ZCompress class implements an LZC compressor and decompressor. It is compatible with the UNIX compress utility.

Syntax

ipworkszip.zcompress()

Remarks

The LZC file format is used only to archive a single file. Accordingly, the operation of the class is simpler than that of the other classs.

To compress with the class, set ArchiveFile to the name of the LZC compressed file to be created, and FileDecompressedName to the name of the file to be compressed. Finally, invoke Compress. To extract the file, first set ArchiveFile. FileDecompressedName may then be set; if not, it will automatically be set based on the ArchiveFile name. Finally, invoke the Extract method.

Example (Creating an LZC File)

ZipControl.ArchiveFile = "c:\test.Z" ZipControl.FileDecompressedName = "c:\test.txt" ZipControl.Compress() Example (Extracting from an LZC File)

ZipControl.ArchiveFile = "c:\test.Z" ZipControl.FileDecompressedName = "c:\test.txt" ZipControl.Extract()

Property List


The following is the full list of the properties of the class with short descriptions. Click on the links for further details.

ArchiveFileThe name of the zip, gzip, tar, or jar archive.
FileDecompressedNameFile name to decompress to, or compress from.
FileInputDataThe data of the file to be compressed.
ZCompressData(Decompression only) The LZC compressed file contents as a byte array.

Method List


The following is the full list of the methods of the class with short descriptions. Click on the links for further details.

AbortAborts the current operation.
CompressCreates the compressed archive.
ConfigSets or retrieves a configuration setting.
ExtractExtracts the compressed file from the archive.
ResetResets the class.

Event List


The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.

BeginFileFired before a file is processed.
EndFileFired after a file is processed.
ErrorInformation about non-fatal errors.
OverwriteFired whenever a file exists and may be overwritten.
ProgressFired as progress is made.

Configuration Settings


The following is a list of configuration settings for the class with short descriptions. Click on the links for further details.

WriteToProgressEventWhether or not to write data to the Progress Event.
BuildInfoInformation about the product's build.
CodePageThe system code page used for Unicode to Multibyte translations.
LicenseInfoInformation about the current license.
UseInternalSecurityAPITells the class whether or not to use the system security libraries or an internal implementation.

ZCompress.ArchiveFile Property

The name of the zip, gzip, tar, or jar archive.

Syntax


 getArchiveFile(): string;


 setArchiveFile(archiveFile: string): void;

Default Value

""

Remarks

This property specifies the name of the archive to be read or written. This property is required when extracting files.

When Scan, Extract, or ExtractAll is invoked, the file specified by ArchiveFile will be opened for read. If the file does not exist, a trappable error will be generated.

When Compress is called, the file named by ArchiveFile will be written; if a file of this name already exists the Overwrite event will be fired. If ArchiveFile is set to the empty string (""), the archive will not be written to disk, and will be provided only through the Progress event.

The filename may be specified with or without a path. Paths may be relative or absolute, and should be specified in the format native to the host operating system. The filename should be specified with the appropriate extension (such as "zip"); an extension will not automatically be appended by the class.

If the file cannot be read, or written, as appropriate, a trappable error will be generated.

Example (Creating an Archive)

ZipControl.ArchiveFile = "c:\test.zip" ZipControl.RecurseSubdirectories = true ZipControl.IncludeFiles("c:\foo\*") ZipControl.Compress()

Note: an archive already open for read may be closed by setting ArchiveFile to the empty string ("").

ZCompress.FileDecompressedName Property

File name to decompress to, or compress from.

Syntax


 getFileDecompressedName(): string;


 setFileDecompressedName(fileDecompressedName: string): void;

Default Value

""

Remarks

FileDecompressedName contains the name of the file in the archive, as stored on the file system, outside the archive.

When compressing a file and SetFileInputStream has not been called with a valid input stream, this property should be specified with a path, if necessary, to allow the file to be found by the class. If the file cannot be found when Compress is called, a trappable error will be generated, and the archive will not be correctly written.

When decompressing files, this property may be set prior to calling Extract. If this property is set to the empty string when Extract is called, Extract will automatically set this property to an appropriate value.

Paths on the local file system should be specified in the format native to the host operating system. They may also be specified in standard (UNIX) format, in which case they will be immediately converted.

ZCompress.FileInputData Property

The data of the file to be compressed.

Syntax


 getFileInputData(): Uint8Array;


 setFileInputData(fileInputData: Uint8Array): void;

Default Value

""

Remarks

When this property is set, the class will read in the data from this property instead of reading from the file contained in the FileDecompressedName property.

This property is not available at design time.

ZCompress.ZCompressData Property

(Decompression only) The LZC compressed file contents as a byte array.

Syntax




 setZCompressData(ZCompressData: Uint8Array): void;

Default Value

""

Remarks

Normally you should set ArchiveFile before invoking Extract. If you prefer to read the LZC compressed file from memory you may set ZCompressData instead. ZCompressData should be set to the entire contents of the LZC compressed file; this will allow you to read from the archive without writing any temporary files to disk.

If you would like to extract data from the archive without ever writing to disk you should also set WriteToProgressEvent to true, and you should set the value of FileDecompressedName to an empty string. Then, when you invoke Extract the data will be provided in the Progress event.

This property is write-only. Note that modifying a LZC compressed file stored in ZCompressData is not supported.

This property is write-only and not available at design time.

ZCompress.abort Method

Aborts the current operation.

Syntax

zcompress.abort(): void

Remarks

Abort may be used to immediately interrupt compression or decompression. Any files partially written by the class will be deleted.

ZCompress.compress Method

Creates the compressed archive.

Syntax

async zcompress.compress(): Promise<void>

Remarks

Invoking Compress creates the archive specified by ArchiveFile. When the method is called, the file specified by FileDecompressedName will be opened, and the file specified by ArchiveFile will contain the compressed output.

ZCompress.config Method

Sets or retrieves a configuration setting.

Syntax

async zcompress.config(configurationString : string): Promise<string>

Remarks

Config is a generic method available in every class. It is used to set and retrieve configuration settings for the class.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

ZCompress.extract Method

Extracts the compressed file from the archive.

Syntax

async zcompress.extract(): Promise<void>

Remarks

Invoking Extract decompresses the archive specified by ArchiveFile. The compressed file will be extracted, and written to disk.

If FileDecompressedName is set to a nonempty string the file will be written there. Otherwise the class will automatically set FileDecompressedName to an appropriate value:

If FileDecompressedName is empty and ArchiveFile ends in ".Z", this filename, less the ".Z" extension will be used. Otherwise the extension ".uncompressed" will be appended to the file name.

ZCompress.reset Method

Resets the class.

Syntax

async zcompress.reset(): Promise<void>

Remarks

Reset resets the state of the class. All properties will be set to their default values, and any files open will be closed.

ZCompress.BeginFile Event

Fired before a file is processed.

Syntax

zcompress.on('BeginFile', listener: (e: {readonly index: number, skip: boolean}) => void )

Remarks

BeginFile is fired before compression or decompression begins. Index will contain 0.

You may use the Skip parameter to tell the component to skip the file when compressing or decompressing.

ZCompress.EndFile Event

Fired after a file is processed.

Syntax

zcompress.on('EndFile', listener: (e: {readonly index: number}) => void )

Remarks

EndFile is fired when compression or decompression finishes. Index will contain 0.

ZCompress.Error Event

Information about non-fatal errors.

Syntax

zcompress.on('Error', listener: (e: {readonly description: string, readonly errorCode: number, readonly index: number, readonly filename: string, ignore: boolean}) => void )

Remarks

The Error event is fired when non-fatal errors occur during compression or decompression. Note that if this event is fired during decompression this may indicate that the archive is corrupt.

By default these errors will cause the component to fail with an exception. The exception may be overridden by setting Ignore to true. This will cause the error to be ignored, the file will be skipped if necessary, and the class will continue operation.

ErrorCode will correspond to one of the following errors:

1Bad or missing CRC-32 checksum.
2Failed to set creation date of a file.
111Can't open file for read (skipping).

Description contains a textual description of the error. Index and Filename contain the array index (where appropriate) and filename of the file being processed at the time of the error.

ZCompress.Overwrite Event

Fired whenever a file exists and may be overwritten.

Syntax

zcompress.on('Overwrite', listener: (e: {filename: string, overwrite: boolean}) => void )

Remarks

Overwrite is fired when a file is about to be overwritten, and would overwrite an existing file. The event is fired during decompression.

Filename contains the full name of the file, specified with its pathname.

Overwrite specifies whether or not the file will be overwritten. For Zip, Jar, and Tar, this is equal by default to the value of the OverwriteFiles property. For Gzip, this value defaults to true.

Either of the parameters may be changed when the event is fired. Changing the value of Overwrite will override the default behavior of the class, and cause the file to be overwritten or not overwritten, depending on the value set. If Filename is changed, the value of Overwrite will be ignored, and the file will be written with the specified name. If a file of the new name also exists this file will be silently overwritten.

ZCompress.Progress Event

Fired as progress is made.

Syntax

zcompress.on('Progress', listener: (e: {readonly data: string, readonly dataB: Uint8Array, readonly filename: string, readonly bytesProcessed: number, readonly percentProcessed: number}) => void )

Remarks

The Progress event is automatically fired as compression or decompression is performed. When WriteToProgressEvent is true, the output data is provided through the Data parameter, allowing for it to be streamed out.

Filename contains the name of the file being written. If no file is being written, Filename will contain an empty string, and the output data will be provided exclusively through this event.

BytesProcessed contains the total number of uncompressed bytes processed. PercentProcessed contains the percent of uncompressed bytes processed, corresponding roughly to the running time of the operation.

For Gzip extraction only, BytesProcessed and PercentProcessed will reflect the number of compressed bytes extracted, as it is generally impossible to predetermine the total uncompressed size.

If WriteToProgressEvent is false, Data will contain null.

Configuration Settings (class ipworkszip.zcompress)

The class accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the Config method.

ZCompress Configuration Settings

WriteToProgressEvent:   Whether or not to write data to the Progress Event.

If WriteToProgressEvent is set to true, then all data produced through invocations of Extract, ExtractAll, and Compress will be written to the Progress event as well as to disk. Applications may stream out the compressed or decompressed data by trapping this event and copying the data.

If WriteToProgressEvent is set to false, the data will not be streamed out, and the Data parameter of the Progress event will contain null.

By default, this config is set to false.

Base Configuration Settings

BuildInfo:   Information about the product's build.

When queried, this setting will return a string containing information about the product's build.

CodePage:   The system code page used for Unicode to Multibyte translations.

The default code page is Unicode UTF-8 (65001).

The following is a list of valid code page identifiers:

IdentifierName
037IBM EBCDIC - U.S./Canada
437OEM - United States
500IBM EBCDIC - International
708Arabic - ASMO 708
709Arabic - ASMO 449+, BCON V4
710Arabic - Transparent Arabic
720Arabic - Transparent ASMO
737OEM - Greek (formerly 437G)
775OEM - Baltic
850OEM - Multilingual Latin I
852OEM - Latin II
855OEM - Cyrillic (primarily Russian)
857OEM - Turkish
858OEM - Multilingual Latin I + Euro symbol
860OEM - Portuguese
861OEM - Icelandic
862OEM - Hebrew
863OEM - Canadian-French
864OEM - Arabic
865OEM - Nordic
866OEM - Russian
869OEM - Modern Greek
870IBM EBCDIC - Multilingual/ROECE (Latin-2)
874ANSI/OEM - Thai (same as 28605, ISO 8859-15)
875IBM EBCDIC - Modern Greek
932ANSI/OEM - Japanese, Shift-JIS
936ANSI/OEM - Simplified Chinese (PRC, Singapore)
949ANSI/OEM - Korean (Unified Hangul Code)
950ANSI/OEM - Traditional Chinese (Taiwan; Hong Kong SAR, PRC)
1026IBM EBCDIC - Turkish (Latin-5)
1047IBM EBCDIC - Latin 1/Open System
1140IBM EBCDIC - U.S./Canada (037 + Euro symbol)
1141IBM EBCDIC - Germany (20273 + Euro symbol)
1142IBM EBCDIC - Denmark/Norway (20277 + Euro symbol)
1143IBM EBCDIC - Finland/Sweden (20278 + Euro symbol)
1144IBM EBCDIC - Italy (20280 + Euro symbol)
1145IBM EBCDIC - Latin America/Spain (20284 + Euro symbol)
1146IBM EBCDIC - United Kingdom (20285 + Euro symbol)
1147IBM EBCDIC - France (20297 + Euro symbol)
1148IBM EBCDIC - International (500 + Euro symbol)
1149IBM EBCDIC - Icelandic (20871 + Euro symbol)
1200Unicode UCS-2 Little-Endian (BMP of ISO 10646)
1201Unicode UCS-2 Big-Endian
1250ANSI - Central European
1251ANSI - Cyrillic
1252ANSI - Latin I
1253ANSI - Greek
1254ANSI - Turkish
1255ANSI - Hebrew
1256ANSI - Arabic
1257ANSI - Baltic
1258ANSI/OEM - Vietnamese
1361Korean (Johab)
10000MAC - Roman
10001MAC - Japanese
10002MAC - Traditional Chinese (Big5)
10003MAC - Korean
10004MAC - Arabic
10005MAC - Hebrew
10006MAC - Greek I
10007MAC - Cyrillic
10008MAC - Simplified Chinese (GB 2312)
10010MAC - Romania
10017MAC - Ukraine
10021MAC - Thai
10029MAC - Latin II
10079MAC - Icelandic
10081MAC - Turkish
10082MAC - Croatia
12000Unicode UCS-4 Little-Endian
12001Unicode UCS-4 Big-Endian
20000CNS - Taiwan
20001TCA - Taiwan
20002Eten - Taiwan
20003IBM5550 - Taiwan
20004TeleText - Taiwan
20005Wang - Taiwan
20105IA5 IRV International Alphabet No. 5 (7-bit)
20106IA5 German (7-bit)
20107IA5 Swedish (7-bit)
20108IA5 Norwegian (7-bit)
20127US-ASCII (7-bit)
20261T.61
20269ISO 6937 Non-Spacing Accent
20273IBM EBCDIC - Germany
20277IBM EBCDIC - Denmark/Norway
20278IBM EBCDIC - Finland/Sweden
20280IBM EBCDIC - Italy
20284IBM EBCDIC - Latin America/Spain
20285IBM EBCDIC - United Kingdom
20290IBM EBCDIC - Japanese Katakana Extended
20297IBM EBCDIC - France
20420IBM EBCDIC - Arabic
20423IBM EBCDIC - Greek
20424IBM EBCDIC - Hebrew
20833IBM EBCDIC - Korean Extended
20838IBM EBCDIC - Thai
20866Russian - KOI8-R
20871IBM EBCDIC - Icelandic
20880IBM EBCDIC - Cyrillic (Russian)
20905IBM EBCDIC - Turkish
20924IBM EBCDIC - Latin-1/Open System (1047 + Euro symbol)
20932JIS X 0208-1990 & 0121-1990
20936Simplified Chinese (GB2312)
21025IBM EBCDIC - Cyrillic (Serbian, Bulgarian)
21027Extended Alpha Lowercase
21866Ukrainian (KOI8-U)
28591ISO 8859-1 Latin I
28592ISO 8859-2 Central Europe
28593ISO 8859-3 Latin 3
28594ISO 8859-4 Baltic
28595ISO 8859-5 Cyrillic
28596ISO 8859-6 Arabic
28597ISO 8859-7 Greek
28598ISO 8859-8 Hebrew
28599ISO 8859-9 Latin 5
28605ISO 8859-15 Latin 9
29001Europa 3
38598ISO 8859-8 Hebrew
50220ISO 2022 Japanese with no halfwidth Katakana
50221ISO 2022 Japanese with halfwidth Katakana
50222ISO 2022 Japanese JIS X 0201-1989
50225ISO 2022 Korean
50227ISO 2022 Simplified Chinese
50229ISO 2022 Traditional Chinese
50930Japanese (Katakana) Extended
50931US/Canada and Japanese
50933Korean Extended and Korean
50935Simplified Chinese Extended and Simplified Chinese
50936Simplified Chinese
50937US/Canada and Traditional Chinese
50939Japanese (Latin) Extended and Japanese
51932EUC - Japanese
51936EUC - Simplified Chinese
51949EUC - Korean
51950EUC - Traditional Chinese
52936HZ-GB2312 Simplified Chinese
54936Windows XP: GB18030 Simplified Chinese (4 Byte)
57002ISCII Devanagari
57003ISCII Bengali
57004ISCII Tamil
57005ISCII Telugu
57006ISCII Assamese
57007ISCII Oriya
57008ISCII Kannada
57009ISCII Malayalam
57010ISCII Gujarati
57011ISCII Punjabi
65000Unicode UTF-7
65001Unicode UTF-8

The following is a list of valid code page identifiers for Mac OS only:

IdentifierName
1ASCII
2NEXTSTEP
3JapaneseEUC
4UTF8
5ISOLatin1
6Symbol
7NonLossyASCII
8ShiftJIS
9ISOLatin2
10Unicode
11WindowsCP1251
12WindowsCP1252
13WindowsCP1253
14WindowsCP1254
15WindowsCP1250
21ISO2022JP
30MacOSRoman
10UTF16String
0x90000100UTF16BigEndian
0x94000100UTF16LittleEndian
0x8c000100UTF32String
0x98000100UTF32BigEndian
0x9c000100UTF32LittleEndian
65536Proprietary

LicenseInfo:   Information about the current license.

When queried, this setting will return a string containing information about the license this instance of a class is using. It will return the following information:

  • Product: The product the license is for.
  • Product Key: The key the license was generated from.
  • License Source: Where the license was found (e.g., RuntimeLicense, License File).
  • License Type: The type of license installed (e.g., Royalty Free, Single Server).
  • Last Valid Build: The last valid build number for which the license will work.
UseInternalSecurityAPI:   Tells the class whether or not to use the system security libraries or an internal implementation.

By default the class will use the system security libraries to perform cryptographic functions where applicable. Setting this to tells the class to use the internal implementation instead of using the system's security API.

Trappable Errors (class ipworkszip.zcompress)

Errors

The following errors may be generated by the class. Note that frequently the error message will contain more specific information than what is listed here.

Note that some non-fatal errors may be trapped and explicitly ignored in the Error event. This will allow the class to continue operation even in case of error.

ZCompress Errors

111   Can't open file for read.
112   Can't open file for write.
113   Can't create directory.
114   The file is too large.
115   Can't create empty archive.
116   The archive must be scanned prior to attempting this operation.
117   The array index is out of range.
118   The maximum size of the archive has been exceeded.
119   The archive must be specified, or streaming must be enabled.
120   The component is busy.
124   Must specify the compressed name.
127   Bad CRC-32 checksum.
128   Unable to set file date.
133   File already exists in the archive.
150   An I/O error has occurred (details follow).

Copyright (c) 2022 /n software inc. - All rights reserved.
IPWorks ZIP 2022 JavaScript Edition - Version 22.0 [Build 8203]