ArchiveWriter Component

Properties   Methods   Events   Config Settings   Errors  

The ArchiveWriter component allows compressing, updating and modifying files for zip, tar, gzip and bzip2 archives.

Syntax

TsbxArchiveWriter

Remarks

Use ArchiveWriter to compress, update, and modify files in archives.

Property List

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

Method List

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

Event List

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

Config Settings

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

ArchiveType Property (ArchiveWriter Component)

The type of the archive.

Syntax

property ArchiveType: TsbxArchiveTypes read get_ArchiveType;

TsbxArchiveTypes = (
  aftUnknown,
  aftZip,
  aftGzip,
  aftBzip2,
  aftTar,
  aftTarGzip,
  aftTarBzip2,
  aftSFX
);

Default Value

aftUnknown

Remarks

This property indicates the type of the opened archive.

This property is read-only.

CompressionAlgorithm Property (ArchiveWriter Component)

Specifies the compression algorithm to use when forming the ZIP archive.

Syntax

property CompressionAlgorithm: Integer read get_CompressionAlgorithm write set_CompressionAlgorithm;

Default Value

8

Remarks

Use this property to select the compression algorithm to be used when creating a ZIP archive.

A typical choice is DEFLATE, which is the default setting. Some implementations also use STORED as an alternative where no compression is required (so the resulting archive is effectively an uncompressed directory of files).

CompressionLevel Property (ArchiveWriter Component)

The compression level to apply to the archived data.

Syntax

property CompressionLevel: Integer read get_CompressionLevel write set_CompressionLevel;

Default Value

6

Remarks

Use this property to specify the compression level to apply to the archived data.

DecryptionCertificates Property (ArchiveWriter Component)

A collection of decryption certificates.

Syntax

property DecryptionCertificates: TsbxCertificateList read get_DecryptionCertificates write set_DecryptionCertificates;

Remarks

Use this property to provide a collection of decryption certificates. All certificates should contain their respective private keys.

When processing an encrypted document, the component will walk through the certificate list to locate the matching decryption certificate. If no such certificate is found, it will fire DecryptionInfoNeeded event to request it.

This property is not available at design time.

Please refer to the Certificate type for a complete list of fields.

DecryptionPassword Property (ArchiveWriter Component)

The decryption password.

Syntax

property DecryptionPassword: String read get_DecryptionPassword write set_DecryptionPassword;

Default Value

''

Remarks

Use this property to provide the decryption password. You can assign it explicitly before commencing file extraction, or provide it on the fly from DecryptionPasswordNeeded event handler.

EncryptionAlgorithm Property (ArchiveWriter Component)

Specifies the encryption algorithm to apply to the archive.

Syntax

property EncryptionAlgorithm: String read get_EncryptionAlgorithm write set_EncryptionAlgorithm;

Default Value

''

Remarks

Use this property to specify the encryption algorithm to apply to the archive.

Component supports the following algorithms: AES128, AES192, AES256, BLOWFISH, TWOFISH, 3DES, 3DES112, DES, RC2, RC4. Note that not all of them may be supported by the processing software.

EncryptionCertificate Property (ArchiveWriter Component)

The encryption certificate.

Syntax

property EncryptionCertificate: TsbxCertificate read get_EncryptionCertificate write set_EncryptionCertificate;

Remarks

Use this property to provide the encryption certificate.

This property is not available at design time.

Please refer to the Certificate type for a complete list of fields.

EncryptionKeyLength Property (ArchiveWriter Component)

The length of the encryption key.

Syntax

property EncryptionKeyLength: Integer read get_EncryptionKeyLength write set_EncryptionKeyLength;

Default Value

0

Remarks

Use this setting to specify the length of the encryption key in bits.

EncryptionPassword Property (ArchiveWriter Component)

Specifies the archive encryption password.

Syntax

property EncryptionPassword: String read get_EncryptionPassword write set_EncryptionPassword;

Default Value

''

Remarks

Use this property to provide the password to encrypt the archive with. Use it alongside EncryptionType and EncryptionAlgorithm properties to set up the whole set of protection settings for the archive.

EncryptionType Property (ArchiveWriter Component)

The type of encryption to apply to the archive.

Syntax

property EncryptionType: TsbxEncryptionTypes read get_EncryptionType write set_EncryptionType;

TsbxEncryptionTypes = (
  aetDefault,
  aetNoEncryption,
  aetGeneric,
  aetWinZip,
  aetStrong
);

Default Value

aetDefault

Remarks

Specifies the encryption type for the archive.

FileData Property (ArchiveWriter Component)

The contents of the file being added to the archive.

Syntax

property FileData: TBytes read get_FileData write set_FileData;

Remarks

Assign this property with a byte array containing the contents of the file being added, if you set the corresponding entry's DataSource to fdsBuffer.

Use FileStream property, with DataSource set to fdsStream, to provide the data in a stream instead. Alternatively, use fdsFile data source to supply the file data in a disk file.

This property is not available at design time.

Files Property (ArchiveWriter Component)

Lists the contents of the archive.

Syntax

property Files: TsbxArchivedFileList read get_Files;

Remarks

This colletction property provides access to all files contained in the archive, both existing and newly added.

Use it to view or adjust properties of specific files, alter their data sources, and tune up actions to be performed on them.

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

Please refer to the ArchivedFile type for a complete list of fields.

FIPSMode Property (ArchiveWriter Component)

Reserved.

Syntax

property FIPSMode: Boolean read get_FIPSMode write set_FIPSMode;

Default Value

false

Remarks

This property is reserved for future use.

NewArchive Property (ArchiveWriter Component)

Indicates whether the archive object represents a new (rather than opened) archive.

Syntax

property NewArchive: Boolean read get_NewArchive;

Default Value

false

Remarks

This property is set to true if the archive is new, or to false if the component control is editing an existing archive.

NewArchive would typically be set to true after a CreateNew call, and to false after an Open call.

This property is read-only.

Opened Property (ArchiveWriter Component)

Indicates whether component is currently in edit mode.

Syntax

property Opened: Boolean read get_Opened;

Default Value

false

Remarks

This property is set to true if the archive control is in edit mode, meaning it was opened with Open or created with CreateNew call.

When an archive is opened, you can add new files to it, remove existing files, or modify encryption attributes.

This property is read-only.

SigningCertificate Property (ArchiveWriter Component)

The certificate to be used for signing.

Syntax

property SigningCertificate: TsbxCertificate read get_SigningCertificate write set_SigningCertificate;

Remarks

Use this property to specify the certificate that shall be used for signing the data. Note that this certificate should have a private key associated with it. Use SigningChain to supply the rest of the certificate chain for inclusion into the signature.

This property is not available at design time.

Please refer to the Certificate type for a complete list of fields.

SigningChain Property (ArchiveWriter Component)

The signing certificate chain.

Syntax

property SigningChain: TsbxCertificateList read get_SigningChain write set_SigningChain;

Remarks

Use this property to provide the chain for the signing certificate. Use the SigningCertificate property, if it is available, to provide the signing certificate itself.

This property is not available at design time.

Please refer to the Certificate type for a complete list of fields.

AddEmptyDir Method (ArchiveWriter Component)

Adds an empty folder to the archive.

Syntax

function AddEmptyDir(Path: String): Integer;

Remarks

Use this method to added an empty folder to the archive with an internal path of Path.

The method returns the index of the new folder entry in the Files collection.

AddFile Method (ArchiveWriter Component)

Adds a file to the archive.

Syntax

function AddFile(Path: String; LocalPath: String): Integer;

Remarks

Use this method to add a disk file to the archive. Provide the local path to the file (e.g. C:\Photos\photo.jpg) via the LocalPath parameter, and the desired path within the archive (e.g. PhotosBackup2020/photo.jpg) via the Path parameter.

AddFiles Method (ArchiveWriter Component)

Adds a group of files to the archive.

Syntax

procedure AddFiles(Folder: String; LocalPath: String; Recursive: Boolean);

Remarks

Use this method to add a collection of files to the archive.

Provide the path to the files on a local system (e.g. C:\photos) via the LocalPath parameter, and set Recursive to indicate whether you want to process the subdirectories recursively. Pass the desired mount point for the files within the archive (e.g. Backup2020/photos) via the Folder parameter.

You can use file mask wildcards in LocalPath to only select the files that match the mask.

AddVirtual Method (ArchiveWriter Component)

Adds a file placeholder to the archive.

Syntax

function AddVirtual(Path: String): Integer;

Remarks

Use this method to add a placeholder for the entry the contents of which is to be provided on the fly from a stream or buffer.

Pass the path to the entry within the archive (e.g. Reports/report2020.csv) via the Path parameter. After the entry has been added, use PrepareFile event or Files property to tune up the type of the data source (file, stream, or memory buffer). During the actual compression, provide the contents of the entry in a stream or buffer in the BeforeCompressFile event handler.

This method returns the index of the new entry in the Files collection.

Close Method (ArchiveWriter Component)

Closes the archive.

Syntax

procedure Close();

Remarks

Use this method to close the current archive and dispose of all the allocated resources.

Call this method when you are done with the archive.

Config Method (ArchiveWriter Component)

Sets or retrieves a configuration setting.

Syntax

function Config(ConfigurationString: String): String;

Remarks

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

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, 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.

CreateNew Method (ArchiveWriter Component)

Creates a new archive.

Syntax

procedure CreateNew(ArchiveType: Integer);

Remarks

Use this method to create a new archive file. Provide the desired archive type in the ArchiveType parameter.

The following archive types are currently supported:

The archive will be kept in memory until written down with Save or SaveStream method.

DoAction Method (ArchiveWriter Component)

Performs an additional action.

Syntax

function DoAction(ActionID: String; ActionParams: String): String;

Remarks

DoAction is a generic method available in every component. It is used to perform an additional action introduced after the product major release. The list of actions is not fixed, and may be flexibly extended over time.

The unique identifier (case insensitive) of the action is provided in the ActionID parameter.

ActionParams contains the value of a single parameter, or a list of multiple parameters for the action in the form of PARAM1=VALUE1;PARAM2=VALUE2;....

Open Method (ArchiveWriter Component)

Opens an archive file.

Syntax

procedure Open(ArchiveType: Integer; ArchiveName: String);

Remarks

Use this method to open an existing archive file for modification.

Provide the path to the archive file via the ArchiveName parameter, and pass the archive type in the ArchiveType parameter.

The following archive types are currently supported:

The archive will be kept in memory until written down with Save or SaveStream method.

OpenBytes Method (ArchiveWriter Component)

Loads an archive file from a byte array.

Syntax

procedure OpenBytes(ArchiveType: Integer; ArchiveBytes: TBytes);

Remarks

Use this method to load an existing archive file from a byte array.

Provide the archive stream via the ArchiveBytes parameter, and pass the archive type in the ArchiveType parameter.

The following archive types are currently supported:

The archive will be kept in memory until written down with Save, SaveStream, or SaveBytes method.

OpenStream Method (ArchiveWriter Component)

Loads an archive file from a stream.

Syntax

procedure OpenStream(ArchiveType: Integer; ArchiveStream: TStream);

Remarks

Use this method to load an existing archive file from a stream.

Provide the archive stream via the ArchiveStream parameter, and pass the archive type in the ArchiveType parameter.

The following archive types are currently supported:

The archive will be kept in memory until written down with Save or SaveStream method.

Remove Method (ArchiveWriter Component)

Removes file(s) and/or folder(s) from the archive.

Syntax

procedure Remove(Path: String);

Remarks

Use this method to remove entries from the archive. Provide an archive-local path via the Path parameter.

Path supports file masks, which makes this method quite powerful (and potentially dangerous).

Save Method (ArchiveWriter Component)

Compresses the archive and saves it to a file.

Syntax

procedure Save(ArchiveName: String);

Remarks

Use this method to finalize all preparations, compress all the entries set up in Files collection, and write the created archive to ArchiveName file.

This method carries out a lot of work and fires a number of events during its execution. Before the compression process starts, PrepareFile event fires repeatedly to provide the summary of what is being included into the archive. A handler of that event is a good place to make last-minute modifications to the data sources, file names, and actions to take upon the files.

Compression of each entry is surrounded with BeforeCompressFile and AfterCompressFile "brackets". Subscribe to BeforeCompressFile to supply the file contents for entries with Buffer and Stream data sources. AfterCompressFile is a good place to release the content stream alloated in the BeforeCompressFile event handler.

Progress event fires repeatedly to report the progress of the current and whole operations. It also provides an opportunity to abort the compression process.

SaveBytes Method (ArchiveWriter Component)

Compresses the archive and saves it to a byte array.

Syntax

function SaveBytes(): TBytes;

Remarks

Use this method to finalize all preparations and compress all entries contained in the Files collection. The method returns the byte array containing the serialized archive.

You can fine-tune the compression process by providing compression details on the fly via the events component fires. See the description of the Save method for the details.

SaveStream Method (ArchiveWriter Component)

Compresses the archive and saves it to a stream.

Syntax

procedure SaveStream(ArchiveStream: TStream);

Remarks

Use this method to finalize all preparations and compress all entries contained in the Files collection to ArchiveStream.

You can fine-tune the compression process by providing compression details on the fly via the events component fires. See the description of the Save method for the details.

UpdateFile Method (ArchiveWriter Component)

Updates an existing compressed entry with a fresher local version.

Syntax

procedure UpdateFile(Path: String; LocalPath: String);

Remarks

Call this method to update the Path entry in the archive with a fresher entry at LocalPath.

UpdateFiles Method (ArchiveWriter Component)

Updates a selection of files in the archive.

Syntax

procedure UpdateFiles(Folder: String; LocalPath: String; AddMissingFiles: Boolean; RemoveMissingFiles: Boolean; Recursive: Boolean);

Remarks

This method is a powerful way to update a subset of files in the archive in accordance with a specified criteria.

Pass an archive-local name of the folder to update via the Folder parameter, and the system-local version of the same folder via the LocalPath parameter. Set AddMissingFiles and RemoveMissingFiles as needed to force inclusion of files missing from the archive, or removal of files missing locally, accordingly.

The Recursive parameter specifies whether the directory should be browsed recursively.

UpdateVirtual Method (ArchiveWriter Component)

Updates an entry in the archive with on-the-fly content.

Syntax

procedure UpdateVirtual(Path: String);

Remarks

Use this method to update content of an existing archive entry. Pass the archive-local entry path via the Path parameter. After updating the entry, tune up its DataSource property in accordance with the desired content origin. Subscribe to BeforeCompressFile to supply the actual data via FileData or FileStream properties.

AfterCompressFile Event (ArchiveWriter Component)

Marks the completion of compression of a file.

Syntax

type TAfterCompressFileEvent = procedure (
  Sender: TObject;
  const Path: String;
  FileSize: Int64;
  DataSource: Integer
) of Object;

property OnAfterCompressFile: TAfterCompressFileEvent read FOnAfterCompressFile write FOnAfterCompressFile;

Remarks

Subscribe to this event to get notified about the completion of compression of a file.

The Path parameter specifies the internal path to the entry inside the archive. The FileSize indicates the size of the file before compression, and the DataSource specifies the type of the source media.

BeforeCompressFile Event (ArchiveWriter Component)

Marks the start of compression of a file.

Syntax

type TBeforeCompressFileEvent = procedure (
  Sender: TObject;
  const Path: String;
  FileSize: Int64;
  DataSource: Integer
) of Object;

property OnBeforeCompressFile: TBeforeCompressFileEvent read FOnBeforeCompressFile write FOnBeforeCompressFile;

Remarks

Subscribe to this event to be notified about the start of compression of an archive entry. The handler of this event is a good place to prepare the desired data source.

The Path parameter indicates the path to the extracted entry in the archive. The FileSize specifies the size of the file before compression. Use this event handler to adjust the data source if the file is to be loaded from a stream or buffer. The DataSource parameter indicates the type of the data media:

If passing the data from a stream or buffer, use AfterCompressFile to dispose of any objects allocated in this event handler (such as the source stream).

Use PrepareFile event to adjust the file data source on the fly.

DecryptionPasswordNeeded Event (ArchiveWriter Component)

Fires when the component needs a password to decrypt the archive.

Syntax

type TDecryptionPasswordNeededEvent = procedure (
  Sender: TObject;
  const PasswordTarget: String;
  var Cancel: Boolean
) of Object;

property OnDecryptionPasswordNeeded: TDecryptionPasswordNeededEvent read FOnDecryptionPasswordNeeded write FOnDecryptionPasswordNeeded;

Remarks

Component fires this event to request a decryption password from the application when it comes across an encrypted archive or entry.

Please assign the password to DecryptionPassword property inside the event handler, or set Cancel to true to cancel the operation.

Error Event (ArchiveWriter Component)

Reports information about errors during archive assembling.

Syntax

type TErrorEvent = procedure (
  Sender: TObject;
  ErrorCode: Integer;
  const Description: String
) of Object;

property OnError: TErrorEvent read FOnError write FOnError;

Remarks

The event is fired in case of exceptional conditions during archive formation.

ErrorCode contains an error code and Description contains a textual description of the error.

Notification Event (ArchiveWriter Component)

This event notifies the application about an underlying control flow event.

Syntax

type TNotificationEvent = procedure (
  Sender: TObject;
  const EventID: String;
  const EventParam: String
) of Object;

property OnNotification: TNotificationEvent read FOnNotification write FOnNotification;

Remarks

The component fires this event to let the application know about some event, occurrence, or milestone in the component. For example, it may fire to report completion of the document processing. The list of events being reported is not fixed, and may be flexibly extended over time.

The unique identifier of the event is provided in the EventID parameter. EventParam contains any parameters accompanying the occurrence. Depending on the type of the component, the exact action it is performing, or the document being processed, one or both may be omitted.

PrepareFile Event (ArchiveWriter Component)

Fires for every file to be compressed before the compression starts.

Syntax

type TPrepareFileEvent = procedure (
  Sender: TObject;
  const Path: String;
  FileSize: Int64;
  var DataSource: Integer;
  var LocalPath: String;
  var Action: Integer
) of Object;

property OnPrepareFile: TPrepareFileEvent read FOnPrepareFile write FOnPrepareFile;

Remarks

Component fires this event for every file included in the Files collection before commencing the compression. This is the last opportunity for your code to adjust the action to be taken for each file and tune up the data sources appropriately.

The Path parameter contains the path to the file within the archive (such as Photos/myphoto.jpg), and the FileSize contains the size of that file before compression.

The DataSource parameter indicates the media from which the file contents is to be taken. A typical default value if fdsFile, but you can adjust the value of that parameter if you need to use an alternative source. The following options are available:

Please do not assign FileStream or FileData in this event handler: this should be done further down the road in the BeforeCompressFile event handler. The purpose of this event is to prepare the compression plan by summarizing what should be done and to which files.

The Action parameter, which is also tuneable, indicates the action for component to take on the file:

Progress Event (ArchiveWriter Component)

Reports the progress of data compression.

Syntax

type TProgressEvent = procedure (
  Sender: TObject;
  Processed: Int64;
  Total: Int64;
  OverallProcessed: Int64;
  OverallTotal: Int64;
  var Cancel: Boolean
) of Object;

property OnProgress: TProgressEvent read FOnProgress write FOnProgress;

Remarks

Subscribe to this event to be notified about compression progress.

Processed and Total report the progress of compression of the current entry; OverallProcessed and OverallTotal report the progress of the whole operation. Set Cancel to true to stop the operation.

RecipientFound Event (ArchiveWriter Component)

Signifies that the archive was found to be encrypted with a digital certificate.

Syntax

type TRecipientFoundEvent = procedure (
  Sender: TObject;
  PublicKeyHash: TBytes;
  CertFound: Boolean
) of Object;

property OnRecipientFound: TRecipientFoundEvent read FOnRecipientFound write FOnRecipientFound;

Remarks

The component fires this event to notify the application that the archive was found to be encrypted with a digital certificate. The hash of the certificate's public key is provided in the PublicKeyHash parameter.

CertFound indicates whether a certificate with a matching public key hash was found in the DecryptionCertificates list. If it wasn't, you need to locate it on the system and add it to that list: component won't be able to decrypt the archive otherwise.

Please note that the certificate must have an associated private key to be capable of decryption.

ArchivedFile Type

Provides information about the compressed file.

Remarks

Use this type to access compressed file details.

Fields

Constructors

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constructor Create();

Creates a new ArchivedFile object.

Certificate Type

Provides details of an individual X.509 certificate.

Remarks

This type provides access to X.509 certificate details.

Fields

Constructors

>

constructor Create();

Creates a new object with default field values.

Config Settings (ArchiveWriter Component)

The component 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 component, access to these internal properties is provided through the Config method.

ArchiveWriter Config Settings

Base Config Settings

Trappable Errors (ArchiveWriter Component)