TDataSource class

Declaration

Inheritance

1. TDataSource
2. TComponent
3. TPersistent
4. TObject

Description

TDatasource is a mediating component: it handles communication between any DB-Aware component (often edit controls on a form) and a TDataset instance. Any database aware component should never communicate with a dataset directly. Instead, it should communicate with a TDatasource instance. The TDataset instance will communicate with the TDatasource instance, which will notify every component attached to it. Vice versa, any component that wishes to make changes to the dataset, will notify the TDatasource instance, which will then (if needed) notify the TDataset instance. The datasource can be disabled, in which case all communication between the dataset and the DB-AWare components is suspended until the datasource is again enabled.

See also

• TDataset
• TDatalink

Properties

DataLinks	protected
DataLink	protected
DataLinkCount	protected
State	public	State of the dataset.
AutoEdit	published	Should the dataset be put in edit mode automatically.
DataSet	published	Dataset this datasource is connected to.
Enabled	published	Enable or disable sending of events.

Methods

DoDataChange	protected
DoStateChange	protected
DoUpdateData	protected
Create	public	Create a new instance of TDatasource.
Destroy	public	Remove a TDatasource instance from memory.
Edit	public	Put the dataset in edit mode, if needed.
IsLinkedTo	public	Check if a dataset is linked to a certain dataset.

Events

OnStateChange	published	Called whenever the state of the dataset changes.
OnDataChange	published	Called whenever data changes in the current record.
OnUpdateData	published	Called whenever the data in the dataset must be updated.

Inherited

From TComponent (74)

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From TPersistent (5)

Assign AssignTo FPOAttachObserver FPODetachObserver FPONotifyObservers

From TObject (37)

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