TChilkatJsonArray Delphi ActiveX Reference Documentation

TChilkatJsonArray

Represents a JSON array, which contains an ordered list of JSON values, where each value can be a string, number, JSON object, JSON array, true, false, or null.

Importing the Chilkat ActiveX into Delphi

Important: Whenever 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. 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) will 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

In Chilkat versions prior to v9.5.0.64, the JSON array should never be explicitly created by an application.
It must be created by an already-existing JSON object (or array) by calling the AddArrayAt method, and then 
fetching it via the ArrayAt method.

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

Properties

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.

property EmitCompact: Integer

Introduced in version 9.5.0.64

If 1 then the Emit method outputs in the most compact form possible (a single-line with no extra whitespace). If 0, then emits with whitespace and indentation to make the JSON human-readable.

The default value is 1.

property EmitCrlf: Integer

Introduced in version 9.5.0.64

If 1 then the Emit method uses CRLF line-endings when emitting the non-compact (pretty-print) format. If 0, then bare-LF's are emitted. (The compact format emits to a single line with no end-of-line characters.) Windows systems traditionally use CRLF line-endings, whereas Linux, Mac OS X, and other systems traditionally use bare-LF line-endings.

The default value is 1.

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).

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.

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.

Concept of LastErrorText

LastErrorText Standard Information

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.

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.

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).

Long Strings Returned by ActiveX Methods in SQL Server

property LastStringResultLen: Integer readonly

Introduced in version 9.5.0.53

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

property Size: Integer readonly

Introduced in version 9.5.0.56

The number of JSON values in the array.

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.

property Version: WideString readonly

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

Methods

function AddArrayAt(index: Integer): Integer;

Introduced in version 9.5.0.56

Inserts a new and empty JSON array member to the position indicated by index. To prepend, pass an index of 0. To append, pass an index of -1. Indexing is 0-based (the 1st member is at index 0).

Returns 1 for success, 0 for failure.

Modify Parts of JSON Document

function AddBoolAt(index: Integer; value: Integer): Integer;

Introduced in version 9.5.0.56

Inserts a new boolean member to the position indicated by index. To prepend, pass an index of 0. To append, pass an index of -1. Indexing is 0-based (the 1st member is at index 0).

Returns 1 for success, 0 for failure.

Modify Parts of JSON Document

function AddIntAt(index: Integer; value: Integer): Integer;

Introduced in version 9.5.0.56

Inserts a new integer member to the position indicated by index. To prepend, pass an index of 0. To append, pass an index of -1. Indexing is 0-based (the 1st member is at index 0).

Returns 1 for success, 0 for failure.

Modify Parts of JSON Document

function AddNullAt(index: Integer): Integer;

Introduced in version 9.5.0.56

Inserts a new null member to the position indicated by index. To prepend, pass an index of 0. To append, pass an index of -1. Indexing is 0-based (the 1st member is at index 0).

Returns 1 for success, 0 for failure.

Modify Parts of JSON Document

function AddNumberAt(index: Integer; numericStr: WideString): Integer;

Introduced in version 9.5.0.56

Inserts a new numeric member to the position indicated by index. The numericStr is an integer, float, or double already converted to a string in the format desired by the application. To prepend, pass an index of 0. To append, pass an index of -1. Indexing is 0-based (the 1st member is at index 0).

Returns 1 for success, 0 for failure.

Create more Complex JSON Document

Modify Parts of JSON Document

function AddObjectAt(index: Integer): Integer;

Introduced in version 9.5.0.56

Inserts a new and empty JSON object member to the position indicated by index. To prepend, pass an index of 0. To append, pass an index of -1. Indexing is 0-based (the 1st member is at index 0).

Returns 1 for success, 0 for failure.

Create more Complex JSON Document

Modify Parts of JSON Document

function AddStringAt(index: Integer; value: WideString): Integer;

Introduced in version 9.5.0.56

Inserts a new string at the position indicated by index. To prepend, pass an index of 0. To append, pass an index of -1. Indexing is 0-based (the 1st member is at index 0).

Returns 1 for success, 0 for failure.

Create more Complex JSON Document

Modify Parts of JSON Document

function ArrayAt(index: Integer): TChilkatJsonArray;

Introduced in version 9.5.0.56

Returns the JSON array that is the value of the Nth array element. Indexing is 0-based (the 1st member is at index 0).

Returns nil on failure

JSON: Nested Array

function BoolAt(index: Integer): Integer;

Introduced in version 9.5.0.56

Returns the boolean value of the Nth array element. Indexing is 0-based (the 1st member is at index 0).

function DeleteAt(index: Integer): Integer;

Introduced in version 9.5.0.56

Deletes the array element at the given index. Indexing is 0-based (the 1st member is at index 0).

Returns 1 for success, 0 for failure.

Modify Parts of JSON Document

function Emit(): WideString;

Introduced in version 9.5.0.58

Writes the JSON array (rooted at the caller) and returns as a string.

Note: To control the compact/non-compact format, and to control the LF/CRLF line-endings, set the EmitCompact and EmitCrlf properties.

Returns a zero-length WideString on failure

function EmitSb(sb: TChilkatStringBuilder): Integer;

Introduced in version 9.5.0.65

Writes the JSON array to the sb.

Note: To control the compact/non-compact format, and to control the LF/CRLF line-endings, set the EmitCompact and EmitCrlf properties.

Returns 1 for success, 0 for failure.

function IntAt(index: Integer): Integer;

Introduced in version 9.5.0.56

Returns the integer value of the Nth array element. Indexing is 0-based (the 1st member is at index 0).

JSON: Access Array Values

function IsNullAt(index: Integer): Integer;

Introduced in version 9.5.0.56

Returns the 1 if the Nth array element is null, otherwise returns 0. Indexing is 0-based (the 1st member is at index 0).

Modify Parts of JSON Document

function Load(jsonArray: WideString): Integer;

Introduced in version 9.5.0.64

Loads a JSON array from a string. A JSON array must begin with a "[" and end with a "]".

Note: The Load method causes the JsonArray to detach and become it's own JSON document. It should only be called on new instances of the JsonArray. See the example below.

Returns 1 for success, 0 for failure.

Load a JsonArray

Loading and Parsing a JSON Array

function LoadSb(sb: TChilkatStringBuilder): Integer;

Introduced in version 9.5.0.64

Loads a JSON array from a StringBuilder. A JSON array must begin with a "[" and end with a "]".

Note: The Load method causes the JsonArray to detach and become it's own JSON document. It should only be called on new instances of the JsonArray. See the example below.

Returns 1 for success, 0 for failure.

Load a JsonArray

function ObjectAt(index: Integer): TChilkatJsonObject;

Introduced in version 9.5.0.56

Returns the JSON object that is the value of the Nth array element. Indexing is 0-based (the 1st member is at index 0).

Returns nil on failure

JSON: Array of Objects

Create more Complex JSON Document

Modify Parts of JSON Document

function SetBoolAt(index: Integer; value: Integer): Integer;

Introduced in version 9.5.0.56

Sets the boolean value of the Nth array element. Indexing is 0-based (the 1st member is at index 0).

Returns 1 for success, 0 for failure.

Modify Parts of JSON Document

function SetIntAt(index: Integer; value: Integer): Integer;

Introduced in version 9.5.0.56

Sets the integer value of the Nth array element. Indexing is 0-based (the 1st member is at index 0).

Returns 1 for success, 0 for failure.

Modify Parts of JSON Document

function SetNullAt(index: Integer): Integer;

Introduced in version 9.5.0.56

Sets the Nth array element to the value of null. Indexing is 0-based (the 1st member is at index 0).

Returns 1 for success, 0 for failure.

function SetNumberAt(index: Integer; value: WideString): Integer;

Introduced in version 9.5.0.56

Sets the numeric value of the Nth array element. The value is an integer, float, or double already converted to a string in the format desired by the application. Indexing is 0-based (the 1st member is at index 0).

Returns 1 for success, 0 for failure.

Modify Parts of JSON Document

function SetStringAt(index: Integer; value: WideString): Integer;

Introduced in version 9.5.0.56

Sets the string value of the Nth array element. Indexing is 0-based (the 1st member is at index 0).

Returns 1 for success, 0 for failure.

Modify Parts of JSON Document

function StringAt(index: Integer): WideString;

Introduced in version 9.5.0.56

Returns the string value of the Nth array element. Indexing is 0-based (the 1st member is at index 0).

Returns a zero-length WideString on failure

JSON: Access Array Values

function TypeAt(index: Integer): Integer;

Introduced in version 9.5.0.58

Returns the type of data at the given index. Possible return values are:

  1. string
  2. number
  3. object
  4. array
  5. boolean
  6. null
Returns -1 if no member exists at the given index.