TDataModule

[Properties (by Name)][Methods (by Name)][Events (by Name)]

Container for non-visual components.

Declaration

Source position: classesh.inc line 2282

Type
  TDataModule = class (TComponent)
  private
    FDPos : TPoint;
    FDSize : TPoint;
    FDPPI : Integer;
    FOnCreate : TNotifyEvent;
    FOnDestroy : TNotifyEvent;
    FOldOrder : Boolean;
    procedure ReadP(Reader: TReader);
    procedure WriteP(Writer: TWriter);
    procedure ReadT(Reader: TReader);
    procedure WriteT(Writer: TWriter);
    procedure ReadL(Reader: TReader);
    procedure WriteL(Writer: TWriter);
    procedure ReadW(Reader: TReader);
    procedure WriteW(Writer: TWriter);
    procedure ReadH(Reader: TReader);
    procedure WriteH(Writer: TWriter);
  protected
    procedure DoCreate;  Virtual;
    procedure DoDestroy;  Virtual;
    procedure DefineProperties(Filer: TFiler);  Override;
    procedure GetChildren(Proc: TGetChildProc; Root: TComponent);  Override;
    function HandleCreateException : Boolean;  Virtual;
    procedure ReadState(Reader: TReader);  Override;
  public
    constructor Create(AOwner: TComponent);  Override;
    constructor CreateNew(AOwner: TComponent);
    constructor CreateNew(AOwner: TComponent; CreateMode: Integer);  Virtual;
    destructor Destroy;  Override;
    procedure AfterConstruction;  Override;
    procedure BeforeDestruction;  Override;
    DesignOffset : TPoint;
    DesignSize : TPoint;
    DesignPPI : Integer;
  published
    OnCreate : TNotifyEvent;
    OnDestroy : TNotifyEvent;
    OldCreateOrder : Boolean;
  end
  ;

Description

TDataModule is a container for non-visual objects which can be used in an IDE to group non-visual objects which can be used by various other containers (forms) in a project. Notably, data access components are typically stored on a datamodule. Web components and services can also be implemented as descendants of datamodules.

TDataModule introduces some events which make it easier to program, and provides the needed streaming capabilities for persistent storage.

An IDE will typically allow to create a descendant of TDataModule which contains non-visual components in it's published property list.

Members

Member	Type	Visibility	Description
AfterConstruction	Method	public	Overrides standard TObject behaviour.
BeforeDestruction	Method	public
Create	Method	public	Create a new instance of a TDataModule.
CreateNew	Method	public
DefineProperties	Method	protected
DesignOffset	Property	public	Position property needed for manipulation in an IDE.
DesignPPI	Property	public	Design Time PPI
DesignSize	Property	public	Size property needed for manipulation in an IDE.
Destroy	Method	public	Destroys the TDataModule instance.
DoCreate	Method	protected
DoDestroy	Method	protected
FDPos	Field	private
FDPPI	Field	private
FDSize	Field	private
FOldOrder	Field	private
FOnCreate	Field	private
FOnDestroy	Field	private
GetChildren	Method	protected
HandleCreateException	Method	protected
OldCreateOrder	Property	published	Determines when OnCreate and OnDestroy are triggered.
OnCreate	Property	published	Event handler, called when the datamodule is created.
OnDestroy	Property	published	Event handler, called when the datamodule is destroyed.
ReadH	Method	private
ReadL	Method	private
ReadP	Method	private
ReadState	Method	protected
ReadT	Method	private
ReadW	Method	private
WriteH	Method	private
WriteL	Method	private
WriteP	Method	private
WriteT	Method	private
WriteW	Method	private

Inheritance

Class	Description
TDataModule	Container for non-visual components.

See also

Name	Description
Integer	A signed 16-bits integer
Integer	A signed 16-bits integer
TDataModule.OnCreate	Event handler, called when the datamodule is created.
TNotifyEvent	Standard event handler type.
TNotifyEvent	Standard event handler type.
TNotifyEvent	Standard event handler type.
TNotifyEvent	Standard event handler type.
TPoint	Special type to handle a fake TComponent position
TPoint	Special type to handle a fake TComponent position
TPoint	Special type to handle a fake TComponent position
TPoint	Special type to handle a fake TComponent position