TP2WDARemoteAdapter

TP2WDARemoteAdapter will use your TP2WDAConnection and connect to your Data Abstract server’s DataService. If your Data Abstract server has more than one DataService, you probably need more than one TP2WDARemoteAdapters.

This component is a wrapper for RemoteDataAdapter and does most of the heavy lifting, including retrieving and updating data.

TP2WDARemoteAdapter encapsulates all the information needed to communicate with the server and to encode and decode data via a data streamer.

Properties

property	description
`Connected`	Determines whether a connection has been established to the Data Abstract server and is active. Set `Connected` to `True` to open the connection. Set `Connected` to `False` to terminate the connection.
`Connection`	You must link this property up to a TP2WDAConnection component for your TP2WDARemoteAdapter to find (and potentially log into) the Data Abstract server.
`DataServiceName`	Specifies the name of the service to retrieve data from, typically this is `DataService`.
`DataStreamer`	A data streamer is responsible for encoding and decoding data packets that are transmitted between client and server over the network. The format in which these streams are encoded is determined by this property. Possible values are `dsBin` or `dsJSON`.
`Options`	Please see: TAdapterOptions

Events

event	description
`OnError`	Fires when an error occurs while logging in, retrieving data, or updating data. If you don't handle this event, it is possible for TP2WDARemoteAdapter to raise an exception. See also: TAdapterOptions.`RetryLoginOnError`.
`OnLoginNeededEx`	Allows for your GUI to display a login dialog when a username and password is needed. `OnLoginNeeded` and `OnLoginNeededEx` are mutually exclusive. You only need to handle one of them. `OnLoginNeededEx` MUST return a promise and resolve to a Boolean value. Do NOT reject the promise.
`OnLoginSuccess`	Fires when this TP2WDARemoteAdapter has successfully logged into the server.
`OnLogoutSuccess`	Fires when this TP2WDARemoteAdapter has successfully logged out of the server.

Unless you use a DataService with custom methods, there is probably no need to handle the following events:

event	description
`OnCreateService`	Most of the time, you will specify a DataService by name and be done with it. However, if your DataService has custom methods you would need to call from Delphi, this event is where to create it. See also: OnCreateService.
`OnLoginNeeded`	You should probably ignore this event and handle the `OnLoginNeededEx` event instead.
`OnGetConnected`	This is handled internally by the component.

When in doubt, handle OnLoginNeededEx and ignore the above events.

TAdapterOptions

option	description
`AutoOpenDataSet`	When `True`, the TP2WDATable or TP2WDAQuery components using this `TP2WDARemoteAdapter` will automatically get opened.
`RetryLoginOnError`	When `True`, this `TP2WDARemoteAdapter` will automatically try and login again when an error occurred.

OnCreateService

Here is an example of a DataService with one or more custom methods. You would need to define a so-called "external class" and then create and return an instance of this class as a response to TP2WDARemoteAdapter.OnCreateService:

type
  TMyDataService = class external name 'MyProject.DataService'(TDataAbstractService)
    procedure MyCustomMethod(onSuccess: TOnSuccess; onFailure: TOnFailure);
  end;

procedure TForm1.DataAdapterCreateService(Sender: TObject; const Channel: TROClientChannel; const Msg: TROMessage; var Service: TROService);
begin
  Service := TMyDataService.new(Channel, Msg, DataAdapter.DataServiceName);
end;

Should you need access to your custom DataService (to call a custom method on it, for example), this is how to get it:

var
  MyDataService: TMyDataService;
begin
  MyDataService := DataAdapter.DataService as TMyDataService;
  ...
end;