ZipEntry JavaScript Reference Documentation

ZipEntry

Current Version: 11.4.0

The Chilkat.ZipEntry class represents a single entry contained within a Chilkat.Zip object.

For a more complete introduction and conceptual overview, see:

ZipEntry Overview

A ZipEntry may represent:

  • A file already contained within an opened ZIP archive
  • A referenced filesystem file that has not yet been compressed
  • An in-memory data entry containing text or binary data
  • A directory entry

ZipEntry objects provide access to ZIP entry metadata such as:

  • Filename and stored ZIP path
  • Compressed and uncompressed sizes
  • Compression method and compression level
  • Encryption information
  • Last-modified timestamps
  • CRC values and entry attributes

ZipEntry objects can also be used to:

  • Extract individual entries
  • Inflate entry contents directly into memory
  • Replace or append entry data
  • Iterate through ZIP archive entries
  • Access compressed entry data

A ZipEntry object is typically obtained from a Chilkat.Zip object using methods such as EntryAt, EntryOf, EntryMatching, or FirstEntry.

The EntryType property indicates the current state of the entry, such as whether it is a mapped entry from an existing ZIP, a referenced filesystem file awaiting compression, or an in-memory data entry.

Object Creation

Note: This is intended for running within a Chilkat.Js embedded JavaScript engine.

var obj = new CkZipEntry();

Properties

Comment
Comment
· string

Gets or sets the comment stored in the ZIP archive for this entry.

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CompressedLength
CompressedLength
· unsigned int, read-only

The compressed size of this entry, in bytes.

For mapped entries (entries already contained within an opened ZIP archive), this property contains the actual compressed size stored within the ZIP.

For file entries or data entries that have not yet been written to a ZIP archive, compression has not yet occurred. In these cases, this property contains:

  • The current uncompressed data size for data entries.
  • The cached filesystem file size for referenced file entries.

After the ZIP archive is written, the entries become mapped entries, and this property then reflects the actual compressed size stored in the ZIP archive.

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CompressedLength64
CompressedLength64
· int64, read-only

The compressed size of this entry, in bytes, as a 64-bit integer.

For mapped entries (entries already contained within an opened ZIP archive), this property contains the actual compressed size stored within the ZIP.

For file entries or data entries that have not yet been written to a ZIP archive, compression has not yet occurred. In these cases, this property contains:

  • The current uncompressed data size for data entries.
  • The cached filesystem file size for referenced file entries.

After the ZIP archive is written, the entries become mapped entries, and this property then reflects the actual compressed size stored in the ZIP archive.

Use this property when sizes may exceed the range of a 32-bit integer.

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CompressedLengthStr
CompressedLengthStr
· string, read-only

The compressed size of this entry as a decimal string.

For mapped entries (entries already contained within an opened ZIP archive), this property contains the actual compressed size stored within the ZIP.

For file entries or data entries that have not yet been written to a ZIP archive, compression has not yet occurred. In these cases, this property contains:

  • The current uncompressed data size for data entries.
  • The cached filesystem file size for referenced file entries.

After the ZIP archive is written, the entries become mapped entries, and this property then reflects the actual compressed size stored in the ZIP archive.

This property is useful when sizes may exceed the range of a 32-bit integer.

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CompressionLevel
CompressionLevel
· int

Gets or sets the compression level for this entry.

A value of 0 means no compression, and a value of 9 means maximum compression.

The default value is 6.

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CompressionMethod
CompressionMethod
· int

Gets or sets the compression method used for this entry.

  • 0 means no compression.
  • 8 means Deflate compression.

Deflate is the standard compression algorithm used by common ZIP utilities such as WinZip.

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Crc
Crc
· int, read-only

The CRC value for this ZIP entry.

For AES-encrypted entries, the CRC value is 0.

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DebugLogFilePath
DebugLogFilePath
· string

If set to a file path, this property logs the LastErrorText of each Chilkat method or property call to the specified file. This logging helps identify the context and history of Chilkat calls leading up to any crash or hang, aiding in debugging.

Enabling the VerboseLogging property provides more detailed information. This property is mainly used for debugging rare instances where a Chilkat method call causes a hang or crash, which should generally not happen.

Possible causes of hangs include:

  • A timeout property set to 0, indicating an infinite timeout.
  • A hang occurring within an event callback in the application code.
  • An internal bug in the Chilkat code causing the hang.

More Information and Examples
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EncryptionKeyLen
EncryptionKeyLen
· int, read-only
Introduced in version 9.5.0.69

The AES encryption key length for this entry.

If this entry is AES encrypted, the value is 128, 192, or 256.

If this entry is not AES encrypted, the value is 0.

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EntryID
EntryID
· int, read-only

A unique identifier assigned to this entry while the ZIP object is instantiated in memory.

This ID can be used to retrieve the same entry later with Zip.EntryById.

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EntryType
EntryType
· int, read-only

Indicates the origin and current state of this ZIP entry.

  • 0 — Mapped Entry: an entry that already exists in an open ZIP file.
  • 1 — File Entry: a file in the local filesystem that has been referenced, but not yet read or compressed.
  • 2 — Data Entry: an entry containing uncompressed data already held in memory.
  • 3 — Null Entry: an entry that no longer exists in the ZIP archive.
  • 4 — New Directory Entry: a directory entry added to the ZIP object.

When the ZIP archive is written by calling WriteZip or WriteToMemory, entries are transformed into mapped entries. In other words, after writing, they point to compressed data contained in the newly created or rewritten ZIP archive.

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FileDateTimeStr
FileDateTimeStr
· string

Gets or sets the local last-modified date/time for this ZIP entry in RFC 822 string format.

Example RFC 822 date/time strings:

Tue, 15 Nov 1994 12:45:26 GMT
Fri, 05 Jan 2024 18:30:00 -0500

The timezone may be specified either as a named timezone such as GMT, or as a numeric UTC offset such as -0500.

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FileName
FileName
· string

Gets or sets the filename, including any relative path, stored for this entry inside the ZIP archive.

Changing this property changes the path/name that will appear in the ZIP archive. It does not rename a source file in the local filesystem.

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FileNameHex
FileNameHex
· string, read-only

Returns the raw filename bytes found in the ZIP entry, encoded as a hexadecimal string.

This can be useful for diagnosing filename encoding issues.

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IsAesEncrypted
IsAesEncrypted
· boolean, read-only
Introduced in version 9.5.0.69

Indicates whether this ZIP entry is AES encrypted.

This property can be true only for entries already contained in a ZIP archive, such as entries obtained after calling OpenZip, OpenBd, or OpenFromMemory.

If the entry is not AES encrypted, the property is false.

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IsDirectory
IsDirectory
· boolean, read-only

Indicates whether this ZIP entry is a directory entry.

The value is true if the entry represents a directory, and false if it represents a file.

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LastErrorHtml
LastErrorHtml
· string, read-only

Provides HTML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorText
LastErrorText
· string, read-only

Provides plain text information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastErrorXml
LastErrorXml
· string, read-only

Provides XML-formatted information about the last called method or property. If a method call fails or behaves unexpectedly, check this property for details. Note that information is available regardless of the method call's success.

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LastMethodSuccess
LastMethodSuccess
· boolean

Indicates the success or failure of the most recent method call: true means success, false means failure. This property remains unchanged by property setters or getters. This method is present to address challenges in checking for null or Nothing returns in certain programming languages. Note: This property does not apply to methods that return integer values or to boolean-returning methods where the boolean does not indicate success or failure.

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TextFlag
TextFlag
· boolean

Gets or sets the text flag in the internal file attributes for this ZIP entry.

This flag indicates whether the entry contents should be considered text rather than binary data.

The flag is informational and does not need to be accurate for normal ZIP processing. It is provided for compatibility with applications that may be sensitive to this attribute.

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UncompressedLength
UncompressedLength
· unsigned int, read-only

The uncompressed size of this entry, in bytes.

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UncompressedLength64
UncompressedLength64
· int64, read-only

The uncompressed size of this entry, in bytes, as a 64-bit integer.

Use this property when the uncompressed size may exceed the range of a 32-bit integer.

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UncompressedLengthStr
UncompressedLengthStr
· string, read-only

The uncompressed size of this ZIP entry as a decimal string.

This is useful when the uncompressed size may be larger than what can safely be represented by a 32-bit integer.

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VerboseLogging
VerboseLogging
· 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
· string, read-only

Version of the component/library, such as "10.1.0"

More Information and Examples
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Methods

AppendString
var success = AppendString(strContent, charset);
· return: boolean; true for success, false for failure
· strContent: string
· charset: string

Appends text data to this ZIP entry's file contents.

The text is converted to bytes using the character encoding specified by charset, such as utf-8, utf-16, or ansi.

If this entry is already a Data Entry (EntryType = 2), then the encoded bytes are appended directly to the existing uncompressed in-memory data.

If this entry is not already a Data Entry, then the entry is first converted into a Data Entry before the new text data is appended.

  • If the entry is a mapped entry (EntryType = 0), the compressed ZIP entry data is first inflated into memory. The new text data is then appended, and the entry becomes a Data Entry containing the combined uncompressed data.
  • If the entry is a file entry (EntryType = 1), the referenced filesystem file is first loaded into memory. The new text data is then appended, and the entry becomes a Data Entry containing the combined data.

After this method is called, the entry contents exist entirely as uncompressed in-memory data associated with the ZipEntry object.

Returns true for success, false for failure.

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CopyToBase64
var strVal = CopyToBase64();
· return: string

Returns the compressed data for this ZIP entry as a Base64-encoded string.

This method can only be used when the entry already contains compressed data, meaning the entry is a mapped entry.

This is possible for entries from a ZIP archive that has already been opened, or after writing a ZIP archive while it remains open.

Returns null on failure

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CopyToHex
var strVal = CopyToHex();
· return: string

Returns the compressed data for this ZIP entry as a hexadecimal encoded string.

This method can only be used when the entry already contains compressed data, meaning the entry is a mapped entry.

This is possible for entries from a ZIP archive that has already been opened, or after writing a ZIP archive while it remains open.

Returns null on failure

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Extract
var success = Extract(dirPath);
· return: boolean; true for success, false for failure
· dirPath: string

Extracts this ZIP entry beneath the specified base directory.

The entry is extracted according to the relative path stored in the ZIP archive.

For example, if the entry filename is docs/readme.txt and dirPath is c:/temp/output, the file is extracted to c:/temp/output/docs/readme.txt.

Use ExtractInto instead if the file should be extracted directly into a specific directory regardless of the path stored in the ZIP archive.

Returns true for success, false for failure.

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ExtractInto
var success = ExtractInto(dirPath);
· return: boolean; true for success, false for failure
· dirPath: string

Extracts this entry directly into the specified directory, ignoring any path information stored in the ZIP entry.

For example, if the entry filename is docs/readme.txt and dirPath is c:/temp/output, the file is extracted to c:/temp/output/readme.txt.

If this entry is a directory entry, nothing is extracted. To create the directory represented by a directory entry, use Extract instead.

Returns true for success, false for failure.

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GetNext
var boolVal = GetNext();
· return: boolean
Introduced in version 11.0.0

Updates this ZipEntry object so that it represents the next entry in the same ZIP archive.

The next entry may be either a file entry or a directory entry.

Returns true if the object was advanced to the next entry. Returns false if there are no more entries.

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GetNextMatch
var boolVal = GetNextMatch(pattern);
· return: boolean
· pattern: string
Introduced in version 11.0.0

Updates this ZipEntry object so that it represents the next entry in the ZIP archive matching the specified wildcard pattern.

The wildcard character * matches zero or more characters. Matching is performed against the full stored filename, including any relative path.

The matching entry may be either a file entry or a directory entry.

Returns true if a matching entry is found. Returns false if no further matching entry exists.

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ReplaceString
var success = ReplaceString(strContent, charset);
· return: boolean; true for success, false for failure
· strContent: string
· charset: string

Replaces this ZIP entry's existing contents with new text data.

The text is converted to bytes using the character encoding specified by charset, such as utf-8 or ansi.

The resulting bytes become the complete contents of the entry.

Returns true for success, false for failure.

More Information and Examples
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SetDt
SetDt(dt);
· return: undefined
· dt: CkDateTime

Sets the last-modified date/time for this ZIP entry.

The dt argument is a CkDateTime object containing the date/time to store for the entry.

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UnzipToBd
var success = UnzipToBd(binData);
· return: boolean; true for success, false for failure
· binData: CkBinData
Introduced in version 9.5.0.67

Unzips this entry directly into a BinData object.

The uncompressed bytes are written to binData.

Returns true for success, false for failure.

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UnzipToSb
var success = UnzipToSb(lineEndingBehavior, srcCharset, sb);
· return: boolean; true for success, false for failure
· lineEndingBehavior: int
· srcCharset: string
· sb: CkStringBuilder
Introduced in version 9.5.0.67

Unzips this entry as text and appends the result to a StringBuilder.

The srcCharset argument specifies how the uncompressed bytes should be interpreted, such as utf-8, utf-16, or windows-1252.

The lineEndingBehavior argument controls line-ending conversion:

  • 0 — leave line endings unchanged.
  • 1 — convert all line endings to bare LF.
  • 2 — convert all line endings to CRLF.

Returns true for success, false for failure.

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UnzipToString
var strVal = UnzipToString(lineEndingBehavior, srcCharset);
· return: string
· lineEndingBehavior: int
· srcCharset: string

Inflates this entry and returns the uncompressed data as a string.

The srcCharset argument specifies how the uncompressed bytes should be interpreted, such as utf-8, utf-16, or windows-1252.

The lineEndingBehavior argument controls line-ending conversion:

  • 0 — leave line endings unchanged.
  • 1 — convert all line endings to bare LF.
  • 2 — convert all line endings to CRLF.

Returns null on failure

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