Overload an Event from TNetHTTPClient (private method not virtual)

Question

I'm creating a component from TNetHTTPClient, and i like to overload the events (procedure declared in private section in TNetHTTPClient) :

  TNetHTTPClient = class(TComponent)
  private
    procedure DoOnRequestCompleted(const Sender: TObject; const AResponse: IHTTPResponse);
    procedure DoOnRequestError(const Sender: TObject; const AError: string);
    procedure DoOnReceiveData(const Sender: TObject; AContentLength: Int64; AReadCount: Int64; var Abort: Boolean);

But i can't call them from my class : like this.

  TRequestAccess = class(TNetHTTPClient)
  private
    procedure ShowLoadAnimation ;
    procedure HideLoadAnimation ;

    procedure DoOnRequestCompleted(const Sender: TObject; const AResponse: IHTTPResponse); override;
    procedure DoOnRequestError(const Sender: TObject; const AError: string); override;
    procedure DoOnReceiveData(const Sender: TObject; AContentLength: Int64; AReadCount: Int64; var Abort: Boolean); override;

...

    procedure TRequestAccess.DoOnReceiveData(const Sender: TObject; AContentLength,
      AReadCount: Int64; var Abort: Boolean);
    begin
      self.HideLoadAnimation ;
      inherited;
    end;

    procedure TRequestAccess.DoOnRequestCompleted(const Sender: TObject;
      const AResponse: IHTTPResponse);
    begin
      self.HideLoadAnimation ;
      inherited;
    end;

    procedure TRequestAccess.DoOnRequestError(const Sender: TObject;
      const AError: string);
    begin
      self.HideLoadAnimation ;
      inherited;
    end;

ShowLoadAnimation and HideLoadAnimation are 2 functions to automatically show and hide a TAniIndicator.

Seems i can't override because it's declared in private and non virtual ?

how can i do this ?

I think i can't rewrite my own function because there is a thread..

procedure TNetHTTPClient.DoOnRequestError(const Sender: TObject; const AError: string);
begin
  if Assigned(FOnRequestError) then
    TThread.Synchronize(nil, procedure
    begin
      FOnRequestError(Sender, AError);
    end);
end;

Answer 1

this work properly. official method from embarcadero.

unit NetHTTPClientUnit;

interface

uses
  System.SysUtils, System.Classes, System.Net.HttpClientComponent,System.Net.HttpClient,System.Net.URLClient;

type
  TNewNetHTTPClient = class(TNetHTTPClient)
  private
    FOnAuthEventInternal        : TCredentialsStorage.TCredentialAuthevent;
    FOnReceiveDataInternal      : TReceiveDataEvent;
    FOnRequestCompletedInternal : TRequestCompletedEvent;
    FOnRequestErrorInternal     : TRequestErrorEvent;

    function GetAuthEventOverride: TCredentialsStorage.TCredentialAuthevent;
    procedure SetAuthEventOverride(const Value: TCredentialsStorage.TCredentialAuthevent);
    function GetOnReceiveData: TReceiveDataEvent;
    function GetOnRequestCompleted: TRequestCompletedEvent;
    function GetOnRequestError: TRequestErrorEvent;
    procedure SetOnReceiveData(const Value: TReceiveDataEvent);
    procedure SetOnRequestCompleted(const Value: TRequestCompletedEvent);
    procedure SetOnRequestError(const Value: TRequestErrorEvent);
    { Private declarations }
    procedure InternalReceiveDataEvent(const Sender: TObject; AContentLength: Int64; AReadCount: Int64; var Abort: Boolean);
    procedure InternalRequestErrorEvent(const Sender: TObject; const AError: string);
    procedure InternalRequestCompletedEvent(const Sender: TObject; const AResponse: IHTTPResponse);
    procedure InternalAuthEvent(const Sender: TObject;
      AnAuthTarget: TAuthTargetType; const ARealm, AURL: string; var AUserName,
      APassword: string; var AbortAuth: Boolean;
      var Persistence: TAuthPersistenceType);

  protected
    { Protected declarations }
  public
    constructor Create(AOwner: TComponent); override;
  published
    /// <summary> UserName needed to be authenticated to the proxy</summary>
    property OnAuthEvent: TCredentialsStorage.TCredentialAuthevent read GetAuthEventOverride write SetAuthEventOverride;
    /// <summary> Event fired when a request finishes</summary>
    property OnRequestCompleted: TRequestCompletedEvent read GetOnRequestCompleted write SetOnRequestCompleted;
    /// <summary> Event fired when a request has an error</summary>
    property OnRequestError: TRequestErrorEvent read GetOnRequestError write SetOnRequestError;
    /// <summary>Property to manage the ReceiveData Event</summary>
    property OnReceiveData: TReceiveDataEvent read GetOnReceiveData write SetOnReceiveData;
  end;

procedure Register;

implementation

Uses WinApi.Windows;

procedure Register;
begin
  RegisterComponents('Net', [TNewNetHTTPClient]);
end;

{ TNewNetHTTPClient }

constructor TNewNetHTTPClient.Create(AOwner: TComponent);
begin
  inherited;
  inherited OnAuthEvent        := InternalAuthEvent;
  inherited OnRequestCompleted := InternalRequestCompletedEvent;
  inherited OnRequestError     := InternalRequestErrorEvent;
  inherited OnReceiveData      := FOnReceiveDataInternal;
end;

function TNewNetHTTPClient.GetAuthEventOverride: TCredentialsStorage.TCredentialAuthevent;
begin
  Result := FOnAuthEventInternal;
end;

function TNewNetHTTPClient.GetOnReceiveData: TReceiveDataEvent;
begin
  result := FOnReceiveDataInternal;
end;

function TNewNetHTTPClient.GetOnRequestCompleted: TRequestCompletedEvent;
begin
   Result := FOnRequestCompletedInternal;
end;

function TNewNetHTTPClient.GetOnRequestError: TRequestErrorEvent;
begin
   Result := FOnRequestErrorInternal;
end;

procedure TNewNetHTTPClient.InternalAuthEvent(const Sender: TObject;
  AnAuthTarget: TAuthTargetType; const ARealm, AURL: string; var AUserName,
  APassword: string; var AbortAuth: Boolean;
  var Persistence: TAuthPersistenceType);
begin
   OutputDebugString('InternalAuthEvent');
   if Assigned(FOnAuthEventInternal) then
       FOnAuthEventInternal(Sender, AnAuthTarget, ARealm, AURL,AUserName,APassword,AbortAuth,Persistence);
end;

procedure TNewNetHTTPClient.InternalReceiveDataEvent(const Sender: TObject;
  AContentLength, AReadCount: Int64; var Abort: Boolean);
begin
   OutputDebugString('InternalReceiveDataEvent');
   if Assigned(FOnReceiveDataInternal) then
          FOnReceiveDataInternal(Sender, AContentLength, AReadCount, Abort);
end;

procedure TNewNetHTTPClient.InternalRequestCompletedEvent(const Sender: TObject;
  const AResponse: IHTTPResponse);
begin
  OutputDebugString('RequestCompletedEvent');
  if AResponse <> nil then
       OutputDebugString( PChar(AResponse.ContentEncoding));
  if Assigned(FOnRequestCompletedInternal) then
      FOnRequestCompletedInternal(Sender,AResponse);
end;

procedure TNewNetHTTPClient.InternalRequestErrorEvent(const Sender: TObject;
  const AError: string);
begin
  OutputDebugString(PChar('RequestErrorEvent ' + AError));
  if Assigned(FOnRequestErrorInternal)  then
         FOnRequestErrorInternal(Sender,AError);
end;

procedure TNewNetHTTPClient.SetAuthEventOverride(
  const Value: TCredentialsStorage.TCredentialAuthevent);
begin
    FOnAuthEventInternal := Value;
end;

procedure TNewNetHTTPClient.SetOnReceiveData(const Value: TReceiveDataEvent);
begin
  FOnReceiveDataInternal := Value;
end;

procedure TNewNetHTTPClient.SetOnRequestCompleted(
  const Value: TRequestCompletedEvent);
begin
   FOnRequestCompletedInternal := Value;
end;

procedure TNewNetHTTPClient.SetOnRequestError(const Value: TRequestErrorEvent);
begin
  FOnRequestErrorInternal := Value;
end;

end.