TDACustomDataAdapter

Overview

The TDACustomDataAdapter class represents the base functions for client-side access to a set of data tables published on the server.

The TDACustomDataAdapter class is the base class for the following descendant classes: the TDABaseDataAdapter class, the TDARemoteDataAdapter class (a centralized visual component for fetching data from a DataAbstract server and sending it back (see more in the Remote Data Adapters article)), the TDALocalDataAdapter class (a visual component that allows access to data from the local service (see more in the Local Data Adapters article)).

The TDACustomDataAdapter class can be used as the base class to retrieve schema information, to fill a DataSet with data from the server or to apply local updates back to the server.

You do not need to use this class directly, but you will often use the descendants of this class: the TDARemoteDataAdapter and TDALocalDataAdapter components.

Location


 

constructor Create  override

Standard component constructor

constructor Create(AOwner: TComponent)

Parameters:

  • AOwner: Owner

ApplyUpdates  virtual abstract

Applies local updates, which are represented in the collection of data tables, back to the server and returns true if the updates were successfully applied on the server. Otherwise returns false.

function ApplyUpdates(aTables: array of TDADataTable; aRefetchAll: Boolean): Boolean

Parameters:

  • aTables: Input collection of data tables with updates that should be applied on the server.
  • aRefetchAll: True: the data tables reopen after applying updates on the server. False: they don't reopen. By default, this parameter equals False.

Assign  override    (declared in TROComponent)

Copies the contents of another, similar object.

procedure Assign(Source: TPersistent)

Parameters:

  • Source: Instance whose properties will be copied

CheckProperties  virtual abstract

Validates the data adapter properties.

procedure CheckProperties(ACheckOnlyDataStreamer: Boolean)

Parameters:

  • ACheckOnlyDataStreamer: True if only the data streamer should be checked, otherwise False. By default, this parameter equals False.

DataStreamer  protected

Defines the type of data streamer to be used for reading and writing data from and to the network. The type of streamer assigned here must match the streamer used on the ServiceDataStreamer property of the sever in the descendant classes.

property DataStreamer: TDADataStreamer read write

Fill (array of TDADataTable, Boolean, Boolean, Boolean)  overload virtual abstract

Retrieves data from the server for all of the specified TDADataTables. In most scenarios you will not call this method yourself, but simply open the respective data table, causing data to be retrieved automatically. However, calling Fill yourself provides additional flexibility, including the option to fill multiple data tables at the same time, avoiding unnecessary server round-trips.

procedure Fill(aTables: array of TDADataTable; aSaveCursor: Boolean; aIncludeSchema: Boolean; aAppendMode: Boolean)

Parameters:

  • aTables: The specified collection of data tables that should receive the data from the server.
  • aSaveCursor: Defines whether the cursors that are related with the collection of data tables should be saved (true) or not (false).
  • aIncludeSchema: Defines whether the schema should be included while creating table request information (true) or not (false).
  • aAppendMode: Defines whether the AppendMode in the related TDATableOptionsArray collection should be set (true) or not (false). By default, this parameter equals false.

FillSchema  virtual abstract

Retrieves schema information for all specified TDADataTables, and configures their Fields and Params setup to match the schema from the server. You can perform the same task at design-time for individual data tables by right-clicking the data table component and selecting "Retrieve DataTable Schema" from the context menu.

procedure FillSchema(aTables: array of TDADataTable; aPreserveLookupFields: Boolean; areserveClientCalcFields: Boolean)

Parameters:

  • aTables: The specified collection of data tables that should receive the schema information.
  • aPreserveLookupFields: Defines whether the collection of lookup fields should be preserved (true) or not (false). By default, this parameter equals false
  • areserveClientCalcFields: Defines whether the collection of calculated fields should be reserved (true) or not (false). By default, this parameter equals false

FillScripts  virtual abstract

Retrieves business rules scripts for all specified TDADataTables from the server.

procedure FillScripts(aTables: array of TDADataTable)

Parameters:

FillWithDASql (array of TDADataTable, array of string)  overload virtual abstract

procedure FillWithDASql(aTables: array of TDADataTable; aSQLs: array of string)

Parameters:

  • aTables:
  • aSQLs:

Get_GetDataCall  protected virtual

Describes the server call that will be used to fetch data from the server.
This function is only used for backward compatibility to provide access to this function in the legacy events in the TDADataTable.

function Get_GetDataCall: TDARemoteRequest

Get_GetSchemaCall  protected virtual

Describes the server call that will be used to obtain schema information from the server.
This function is only used for backward compatibility to provide access to this function in the legacy events in the TDADataTable.

function Get_GetSchemaCall: TDARemoteRequest

Get_GetScriptsCall  protected virtual

Gets access to the server call that will be used to download business rules scripts.
This function is only used for backward compatibility to provide access to this function in the legacy events in the TDADataTable

function Get_GetScriptsCall: TDARemoteRequest

Get_UpdateDataCall  protected virtual

Describes the server call that will be used to apply changes back to the server.
This function is only used for backward compatibility to provide access to this function in the legacy events in the TDADataTable.

function Get_UpdateDataCall: TDARemoteRequest

GetLinkedTables

Returns list of datatables that use given DataAdapter

function GetLinkedTables: TList<TComponent>

Notification  protected override

Forwards notification messages to all owned components.

procedure Notification(AComponent: TComponent; Operation: TOperation)

Parameters:

  • AComponent: component
  • Operation: operation

ROFreeNotification    (declared in TROComponent)

Forwards notification messages to all owned components.

procedure ROFreeNotification(aComponent: TComponent)

Parameters:

  • aComponent: component

RORemoveFreeNotification    (declared in TROComponent)

Forwards notification messages to all owned components.

procedure RORemoveFreeNotification(aComponent: TComponent)

Parameters:

  • aComponent: component

Schema  protected

Server's schema.

property Schema: TDAClientSchema read

SendRemoveNotification  protected    (declared in TROComponent)

Forwards notification messages to all owned components.

procedure SendRemoveNotification(aComponent: TComponent)

Parameters:

  • aComponent: component

 

DataStreamer  protected

Defines the type of data streamer to be used for reading and writing data from and to the network. The type of streamer assigned here must match the streamer used on the ServiceDataStreamer property of the sever in the descendant classes.

property DataStreamer: TDADataStreamer read write

Schema  protected

Server's schema.

property Schema: TDAClientSchema read

 

constructor Create  override

Standard component constructor

constructor Create(AOwner: TComponent)

Parameters:

  • AOwner: Owner

ApplyUpdates  virtual abstract

Applies local updates, which are represented in the collection of data tables, back to the server and returns true if the updates were successfully applied on the server. Otherwise returns false.

function ApplyUpdates(aTables: array of TDADataTable; aRefetchAll: Boolean): Boolean

Parameters:

  • aTables: Input collection of data tables with updates that should be applied on the server.
  • aRefetchAll: True: the data tables reopen after applying updates on the server. False: they don't reopen. By default, this parameter equals False.

Assign  override    (declared in TROComponent)

Copies the contents of another, similar object.

procedure Assign(Source: TPersistent)

Parameters:

  • Source: Instance whose properties will be copied

CheckProperties  virtual abstract

Validates the data adapter properties.

procedure CheckProperties(ACheckOnlyDataStreamer: Boolean)

Parameters:

  • ACheckOnlyDataStreamer: True if only the data streamer should be checked, otherwise False. By default, this parameter equals False.

Fill (array of TDADataTable, Boolean, Boolean, Boolean)  overload virtual abstract

Retrieves data from the server for all of the specified TDADataTables. In most scenarios you will not call this method yourself, but simply open the respective data table, causing data to be retrieved automatically. However, calling Fill yourself provides additional flexibility, including the option to fill multiple data tables at the same time, avoiding unnecessary server round-trips.

procedure Fill(aTables: array of TDADataTable; aSaveCursor: Boolean; aIncludeSchema: Boolean; aAppendMode: Boolean)

Parameters:

  • aTables: The specified collection of data tables that should receive the data from the server.
  • aSaveCursor: Defines whether the cursors that are related with the collection of data tables should be saved (true) or not (false).
  • aIncludeSchema: Defines whether the schema should be included while creating table request information (true) or not (false).
  • aAppendMode: Defines whether the AppendMode in the related TDATableOptionsArray collection should be set (true) or not (false). By default, this parameter equals false.

FillSchema  virtual abstract

Retrieves schema information for all specified TDADataTables, and configures their Fields and Params setup to match the schema from the server. You can perform the same task at design-time for individual data tables by right-clicking the data table component and selecting "Retrieve DataTable Schema" from the context menu.

procedure FillSchema(aTables: array of TDADataTable; aPreserveLookupFields: Boolean; areserveClientCalcFields: Boolean)

Parameters:

  • aTables: The specified collection of data tables that should receive the schema information.
  • aPreserveLookupFields: Defines whether the collection of lookup fields should be preserved (true) or not (false). By default, this parameter equals false
  • areserveClientCalcFields: Defines whether the collection of calculated fields should be reserved (true) or not (false). By default, this parameter equals false

FillScripts  virtual abstract

Retrieves business rules scripts for all specified TDADataTables from the server.

procedure FillScripts(aTables: array of TDADataTable)

Parameters:

FillWithDASql (array of TDADataTable, array of string)  overload virtual abstract

procedure FillWithDASql(aTables: array of TDADataTable; aSQLs: array of string)

Parameters:

  • aTables:
  • aSQLs:

Get_GetDataCall  protected virtual

Describes the server call that will be used to fetch data from the server.
This function is only used for backward compatibility to provide access to this function in the legacy events in the TDADataTable.

function Get_GetDataCall: TDARemoteRequest

Get_GetSchemaCall  protected virtual

Describes the server call that will be used to obtain schema information from the server.
This function is only used for backward compatibility to provide access to this function in the legacy events in the TDADataTable.

function Get_GetSchemaCall: TDARemoteRequest

Get_GetScriptsCall  protected virtual

Gets access to the server call that will be used to download business rules scripts.
This function is only used for backward compatibility to provide access to this function in the legacy events in the TDADataTable

function Get_GetScriptsCall: TDARemoteRequest

Get_UpdateDataCall  protected virtual

Describes the server call that will be used to apply changes back to the server.
This function is only used for backward compatibility to provide access to this function in the legacy events in the TDADataTable.

function Get_UpdateDataCall: TDARemoteRequest

GetLinkedTables

Returns list of datatables that use given DataAdapter

function GetLinkedTables: TList<TComponent>

Notification  protected override

Forwards notification messages to all owned components.

procedure Notification(AComponent: TComponent; Operation: TOperation)

Parameters:

  • AComponent: component
  • Operation: operation

ROFreeNotification    (declared in TROComponent)

Forwards notification messages to all owned components.

procedure ROFreeNotification(aComponent: TComponent)

Parameters:

  • aComponent: component

RORemoveFreeNotification    (declared in TROComponent)

Forwards notification messages to all owned components.

procedure RORemoveFreeNotification(aComponent: TComponent)

Parameters:

  • aComponent: component

SendRemoveNotification  protected    (declared in TROComponent)

Forwards notification messages to all owned components.

procedure SendRemoveNotification(aComponent: TComponent)

Parameters:

  • aComponent: component