TChilkatBz2 Delphi ActiveX Reference Documentation

TChilkatBz2

Current Version: 9.5.0.73

Provides the ability to create and unzip .bz2 compressed files using the BZip2 compression algorithm.

Importing the Chilkat ActiveX into Delphi

Important: When upgrading to a new version of Chilkat, make sure to re-imported ActiveX DLL into Delphi to regenerate the files described below.

Two things are required to use an ActiveX in Delphi:

  1. The ActiveX DLL needs to be registered via regsvr32 on the system where the Delphi application runs. See How To Register ActiveX DLLs for detailed information.
  2. See also: ActiveX Registration Tutorial
  3. The ActiveX component needs to be "imported". Use the Delphi Import Component Wizard to import the Chilkat type library. This creates the following files: Chilkat_v9_5_0_TLB.pas and Chilkat_v9_5_0_TLB.dcr. The Chilkat_v9_5_0_TLB.pas should be added to your project.

To import the Chilkat type library, do the following:

  1. In the Delphi RAD Studio, select the menu item "Component" --> "Import a Type Library".
  2. Find "Chilkat ActiveX v9.5.0" in the list and select it. This will only appear in the list if the ChilkatAx-9.5.0-win32.dll (or ChilkatAx-9.5.0-x64.dll) has been registered w/ regsvr32.
  3. Check the "Generate Component Wrappers" checkbox.
  4. Select a directory where the unit files (.pas and .dcr) should be generated.
  5. Select "Create Unit" and then "Finish".
  6. Add the .pas to your Delphi project.

To use a Chilkat ActiveX object in your Delphi code, add "Chilkat_v9_5_0_TLB" to the "uses" statement. For example:

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_v9_5_0_TLB;

Object Creation

var
obj: TChilkatBz2;
...
begin
obj := TChilkatBz2.Create(Self);
...
// When finished, free the object instance.
obj.Free();

Properties

AbortCurrent
property AbortCurrent: Integer
Introduced in version 9.5.0.58

When set to 1, 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 0 when the next method is called. When the abort occurs, this property is reset to 0. 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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DebugLogFilePath
property DebugLogFilePath: WideString

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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HeartbeatMs
property HeartbeatMs: Integer

To be documented soon...

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LastBinaryResult
property LastBinaryResult: OleVariant readonly
Introduced in version 9.5.0.52

The binary data returned by the last (binary data returning) method called. Only available if Chilkat.Global.KeepBinaryResult is set to 1. This provides a means for obtaining large varbinary results in the SQL Server environment (where limitations exist in getting large amounts of data returned by method calls, but where temp tables can be used for binary properties).

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LastErrorHtml
property LastErrorHtml: WideString readonly

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 LastErrorText: WideString readonly

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 LastErrorXml: WideString readonly

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 LastMethodSuccess: Integer
Introduced in version 9.5.0.52

Indicate whether the last method call succeeded or failed. A value of 1 indicates success, a value of 0 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 = 1 and failure = 0.
  • 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 1. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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LastStringResult
property LastStringResult: WideString readonly
Introduced in version 9.5.0.52

The string return value of the last (string returning) method called. Only available if Chilkat.Global.KeepStringResult is set to 1. This provides a means for obtaining large string results in the SQL Server environment (where limitations exist in getting long strings returned by method calls, but where temp tables can be used for string properties).

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LastStringResultLen
property LastStringResultLen: Integer readonly
Introduced in version 9.5.0.53

The length, in characters, of the string contained in the LastStringResult property.

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VerboseLogging
property VerboseLogging: Integer

If set to 1, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is 0. 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 Version: WideString readonly

Version of the component/library, such as "9.5.0.63"

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Methods

CompressFile
function CompressFile(inFilename: WideString; toPath: WideString): Integer;

Compresses a file to create a BZip2 compressed file (.bz2).

Returns 1 for success, 0 for failure.

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CompressFileAsync (1)
function CompressFileAsync(inFilename: WideString; toPath: WideString): TChilkatTask;

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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CompressFileToMem
function CompressFileToMem(inFilename: WideString): OleVariant;

BZip2 compresses a file to an in-memory image of a .bz2 file.

Returns a zero-length byte array (as an OleVariant) on failure.
An empty array will have a VarArrayHighBound of -1 meaning 0 elements.

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CompressFileToMemAsync (1)
function CompressFileToMemAsync(inFilename: WideString): TChilkatTask;

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
function CompressMemory(inData: OleVariant): OleVariant;

Compresses in-memory data to an in-memory image of a .bz2 file.

Returns a zero-length byte array (as an OleVariant) on failure.
An empty array will have a VarArrayHighBound of -1 meaning 0 elements.

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CompressMemoryAsync (1)
function CompressMemoryAsync(inData: OleVariant): TChilkatTask;

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
function CompressMemToFile(inData: OleVariant; toPath: WideString): Integer;

BZip2 compresses and creates a .bz2 file from in-memory data.

Returns 1 for success, 0 for failure.

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CompressMemToFileAsync (1)
function CompressMemToFileAsync(inData: OleVariant; toPath: WideString): TChilkatTask;

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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UncompressFile
function UncompressFile(inFilename: WideString; toPath: WideString): Integer;

Unzips a .bz2 file.

Returns 1 for success, 0 for failure.

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UncompressFileAsync (1)
function UncompressFileAsync(inFilename: WideString; toPath: WideString): TChilkatTask;

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
function UncompressFileToMem(inFilename: WideString): OleVariant;

Unzips a .bz2 file directly to memory.

Returns a zero-length byte array (as an OleVariant) on failure.
An empty array will have a VarArrayHighBound of -1 meaning 0 elements.

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UncompressFileToMemAsync (1)
function UncompressFileToMemAsync(inFilename: WideString): TChilkatTask;

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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UncompressMemory
function UncompressMemory(inData: OleVariant): OleVariant;

Unzips from an in-memory image of a .bz2 file directly into memory.

Returns a zero-length byte array (as an OleVariant) on failure.
An empty array will have a VarArrayHighBound of -1 meaning 0 elements.

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UncompressMemoryAsync (1)
function UncompressMemoryAsync(inData: OleVariant): TChilkatTask;

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
function UncompressMemToFile(inData: OleVariant; toPath: WideString): Integer;

Unzips from an in-memory image of a .bz2 file to a file.

Returns 1 for success, 0 for failure.

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UncompressMemToFileAsync (1)
function UncompressMemToFileAsync(inData: OleVariant; toPath: WideString): TChilkatTask;

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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UnlockComponent
function UnlockComponent(regCode: WideString): Integer;

Unlocks the component allowing for the full functionality to be used. If a purchased unlock code is passed, there is no expiration. Any other string automatically begins a fully-functional 30-day trial the first time UnlockComponent is called.

Returns 1 for success, 0 for failure.

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Events

AbortCheck
procedure AbortCheck(ASender: TObject; out abort: Integer);

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.

Delphi ActiveX Event callback implementation:

procedure TForm1.bzENTRY_NAME(ASender: TObject;  out abort: Integer);
begin
    // Application code goes here...
end;


procedure TForm1.Button1Click(Sender: TObject);
var
  bz: TChilkatBz2;

begin
  bz := TChilkatBz2.Create(Self);
  bz.OnAbortCheck := bzAbortCheck;
  // ...
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PercentDone
procedure PercentDone(ASender: TObject; pctDone: Integer; out abort: Integer);

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

Delphi ActiveX Event callback implementation:

procedure TForm1.bzENTRY_NAME(ASender: TObject;  pctDone: Integer; out abort: Integer);
begin
    // Application code goes here...
end;


procedure TForm1.Button1Click(Sender: TObject);
var
  bz: TChilkatBz2;

begin
  bz := TChilkatBz2.Create(Self);
  bz.OnPercentDone := bzPercentDone;
  // ...
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ProgressInfo
procedure ProgressInfo(ASender: TObject; const name: WideString; const value: WideString);

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.

Delphi ActiveX Event callback implementation:

procedure TForm1.bzENTRY_NAME(ASender: TObject;  const name: WideString; const value: WideString);
begin
    // Application code goes here...
end;


procedure TForm1.Button1Click(Sender: TObject);
var
  bz: TChilkatBz2;

begin
  bz := TChilkatBz2.Create(Self);
  bz.OnProgressInfo := bzProgressInfo;
  // ...
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TaskCompleted
procedure TaskCompleted(ASender: TObject; const task: IChilkatTask);

Called in the background thread when an asynchronous task completes.

More Information and Examples

Delphi ActiveX Event callback implementation:

procedure TForm1.bzENTRY_NAME(ASender: TObject;  const task: IChilkatTask);
begin
    // Application code goes here...
end;


procedure TForm1.Button1Click(Sender: TObject);
var
  bz: TChilkatBz2;

begin
  bz := TChilkatBz2.Create(Self);
  bz.OnTaskCompleted := bzTaskCompleted;
  // ...
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