CEF4Delphi/demos/Delphi_VCL/URLRequest/uURLRequest.pas

// ************************************************************************
// ***************************** CEF4Delphi *******************************
// ************************************************************************
//
// CEF4Delphi is based on DCEF3 which uses CEF to embed a chromium-based
// browser in Delphi applications.
//
// The original license of DCEF3 still applies to CEF4Delphi.
//
// For more information about CEF4Delphi visit :
//         https://www.briskbard.com/index.php?lang=en&pageid=cef
//
//        Copyright <20> 2020 Salvador D<>az Fau. All rights reserved.
//
// ************************************************************************
// ************ vvvv Original license and comments below vvvv *************
// ************************************************************************
(*
 *                       Delphi Chromium Embedded 3
 *
 * Usage allowed under the restrictions of the Lesser GNU General Public License
 * or alternatively the restrictions of the Mozilla Public License 1.1
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
 * the specific language governing rights and limitations under the License.
 *
 * Unit owner : Henri Gourvest <hgourvest@gmail.com>
 * Web site   : http://www.progdigy.com
 * Repository : http://code.google.com/p/delphichromiumembedded/
 * Group      : http://groups.google.com/group/delphichromiumembedded
 *
 * Embarcadero Technologies, Inc is not permitted to use or redistribute
 * this source code without explicit permission.
 *
 *)

unit uURLRequest;

interface

uses
  {$IFDEF DELPHI16_UP}
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.ComCtrls, Vcl.StdCtrls,
  {$ELSE}
  Windows, Messages, SysUtils, Variants, Classes, Graphics,
  Controls, Forms, Dialogs, ComCtrls, StdCtrls,
  {$ENDIF}
  uCEFInterfaces, uCEFUrlRequestClientComponent, uCEFRequest, uCEFUrlRequest,
  uCEFSentinel;

const
  URLREQUEST_SUCCESS    = WM_APP + $101;
  URLREQUEST_ERROR      = WM_APP + $102;

type
  TURLRequestFrm = class(TForm)
    StatusBar1: TStatusBar;
    SaveDialog1: TSaveDialog;
    CEFUrlRequestClientComponent1: TCEFUrlRequestClientComponent;
    GETGbx: TGroupBox;
    DownloadBtn: TButton;
    GetURLEdt: TEdit;
    Label1: TLabel;
    POSTGbx: TGroupBox;
    PostURLEdt: TEdit;
    Label2: TLabel;
    SendPostReqBtn: TButton;
    Button1: TButton;
    GroupBox1: TGroupBox;
    Label3: TLabel;
    PostParam1NameEdt: TEdit;
    Label4: TLabel;
    PostParam1ValueEdt: TEdit;
    GroupBox2: TGroupBox;
    Label5: TLabel;
    Label6: TLabel;
    PostParam2NameEdt: TEdit;
    PostParam2ValueEdt: TEdit;

    procedure DownloadBtnClick(Sender: TObject);
    procedure SendPostReqBtnClick(Sender: TObject);
    procedure Button1Click(Sender: TObject);

    procedure FormDestroy(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);

    procedure CEFUrlRequestClientComponent1DownloadData(Sender: TObject; const request: ICefUrlRequest; data: Pointer; dataLength: NativeUInt);
    procedure CEFUrlRequestClientComponent1DownloadProgress(Sender: TObject; const request: ICefUrlRequest; current, total: Int64);
    procedure CEFUrlRequestClientComponent1RequestComplete(Sender: TObject; const request: ICefUrlRequest);
    procedure CEFUrlRequestClientComponent1CreateURLRequest(Sender: TObject);

  private
    FMemStream      : TMemoryStream;
    FCanClose       : boolean;
    FClosing        : boolean;
    FBusy           : boolean;
    FPendingURL     : string;
    FSendingGET     : boolean;
    FSendingPOST    : boolean;

    procedure CreateGETRequest;
    procedure CreatePOSTRequest;

    procedure URLRequestSuccessMsg(var aMessage : TMessage); message URLREQUEST_SUCCESS;
    procedure URLRequestErrorMsg(var aMessage : TMessage); message URLREQUEST_ERROR;

    procedure SaveStreamToFile;
  end;

var
  URLRequestFrm: TURLRequestFrm;

procedure CreateGlobalCEFApp;

implementation

{$R *.dfm}

// This is a simple URL request example to download small files using TCEFUrlRequestClientComponent.
// WARNING : If you try to download big files you may get an "Out of memory" exception. Replace TMemoryStream in that case.

// All TCEFUrlRequestClientComponent events are executed in a different thread. Don't create or destroy VCL componets
// inside them.

// To keep this demo as simple as possible, it's only allowed to download one file at a time. You can add as many requests
// as you want but then you would have to use a different way to store the data with synchronization objects.

// It's much safer to cancel all requests before closing the app.
// This demo follows this destruction sequence in case there is a file download running :
// --------------------------------------------------------------------------------------
// 1- Set CanClose to FALSE in the TForm.OnCloseQuery event and set FClosing to TRUE.
// 2- The next time TCEFUrlRequestClientComponent.OnDownloadProgress is executed we call request.Cancel, which triggers the
//    TCEFUrlRequestClientComponent.OnRequestComplete event.
// 3- in the TCEFUrlRequestClientComponent.OnRequestComplete event we call TCEFSentinel.Start, which will trigger TCEFSentinel.OnClose when the renderer processes are closed.
// 4- TCEFSentinel.OnClose sets FCanClose := True and sends WM_CLOSE to the form.

uses
  ShellApi,
  uCEFApplication, uCEFMiscFunctions, uCEFTypes, uCEFPostData, uCEFPostDataElement, uCEFConstants;

procedure CreateGlobalCEFApp;
begin
  GlobalCEFApp                 := TCefApplication.Create;
  //GlobalCEFApp.LogFile          := 'cef.log';
  //GlobalCEFApp.LogSeverity      := LOGSEVERITY_VERBOSE;
end;

procedure TURLRequestFrm.DownloadBtnClick(Sender: TObject);
var
  TempURL, TempPath, TempName : string;
  TempParts : TUrlParts;
  i : integer;
begin
  TempURL := trim(GetURLEdt.Text);

  if (length(TempURL) > 0) then
    begin
      CefParseUrl(TempURL, TempParts);
      TempPath := trim(TempParts.path);
      TempName := '';

      if (length(TempPath) > 0) then
        begin
          i := LastDelimiter('/', TempPath);

          if (i > 0) then
            TempName := trim(copy(TempPath, succ(i), length(TempPath)))
           else
            TempName := TempPath;
        end;

      if (length(TempName) > 0) then
        SaveDialog1.FileName := TempName  // This name should be decoded and sanitized before using it in Windows
       else
        SaveDialog1.FileName := 'UnknownFileName';

      if SaveDialog1.Execute and
         (length(SaveDialog1.FileName) > 0) then
        begin
          FPendingURL               := TempURL;
          GETGbx.Enabled            := False;
          POSTGbx.Enabled           := False;
          StatusBar1.Panels[0].Text := 'Downloading...';
          FMemStream.Clear;

          FSendingPOST := False;
          FSendingGET  := True;

          // TCEFUrlRequestClientComponent.AddURLRequest will trigger the
          // TCEFUrlRequestClientComponent.OnCreateURLRequest event in the right
          // thread where you can create your custom requests.
          CEFUrlRequestClientComponent1.AddURLRequest;
        end;
    end;
end;

procedure TURLRequestFrm.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
begin
  CanClose := FCanClose or not(FBusy);
  FClosing := True;
end;

procedure TURLRequestFrm.FormCreate(Sender: TObject);
begin
  FMemStream   := TMemoryStream.Create;
  FCanClose    := False;
  FClosing     := False;
  FBusy        := False;
  FSendingGET  := False;
  FSendingPOST := False;
end;

procedure TURLRequestFrm.FormDestroy(Sender: TObject);
begin
  if (FMemStream <> nil) then FreeAndNil(FMemStream);
end;

procedure TURLRequestFrm.Button1Click(Sender: TObject);
begin
  ShellExecute(0, 'open', 'https://ptsv2.com/t/cef4delphi', nil, nil, SW_SHOWNORMAL);
end;

procedure TURLRequestFrm.CEFUrlRequestClientComponent1CreateURLRequest(Sender: TObject);
begin
  if FSendingGET then
    CreateGETRequest
   else
    if FSendingPOST then
      CreatePOSTRequest;
end;

procedure TURLRequestFrm.CreateGETRequest;
var
  TempRequest  : ICefRequest;
begin
  try
    if (length(FPendingURL) > 0) then
      begin
        FBusy              := True;
        TempRequest        := TCefRequestRef.New;
        TempRequest.URL    := FPendingURL;
        TempRequest.Method := 'GET';
        TempRequest.Flags  := UR_FLAG_ALLOW_STORED_CREDENTIALS;

        // Set the "client" parameter to the TCEFUrlRequestClientComponent.Client property
        // to use the TCEFUrlRequestClientComponent events.
        // The "requestContext" parameter can be nil to use the global request context.
        TCefUrlRequestRef.New(TempRequest, CEFUrlRequestClientComponent1.Client, nil);
      end;
  finally
    TempRequest := nil;
  end;
end;

procedure TURLRequestFrm.CreatePOSTRequest;
var
  TempRequest    : ICefRequest;
  TempPostData   : ICefPostData;
  TempElement    : ICefPostDataElement;
  TempParams     : AnsiString;
begin
  try
    if (length(FPendingURL) > 0) then
      begin
        FBusy              := True;

        TempRequest        := TCefRequestRef.New;
        TempRequest.URL    := FPendingURL;
        TempRequest.Method := 'POST';
        TempRequest.Flags  := UR_FLAG_ALLOW_STORED_CREDENTIALS;

        // TODO : The parameters should be converted to ansistring and encoded
        if (length(PostParam1NameEdt.Text) > 0) and (length(PostParam1ValueEdt.Text) > 0) then
          TempParams := PostParam1NameEdt.Text + '=' + PostParam1ValueEdt.Text;

        if (length(PostParam2NameEdt.Text) > 0) and (length(PostParam2ValueEdt.Text) > 0) then
          begin
            if (length(TempParams) > 0) then
              TempParams := TempParams + '&' + PostParam2NameEdt.Text + '=' + PostParam2ValueEdt.Text
             else
              TempParams := PostParam2NameEdt.Text + '=' + PostParam2ValueEdt.Text;
          end;


        if (length(TempParams) > 0) then
          begin
            TempElement := TCefPostDataElementRef.New;
            TempElement.SetToBytes(length(TempParams), @TempParams[1]);

            TempPostData := TCefPostDataRef.New;
            TempPostData.AddElement(TempElement);

            TempRequest.PostData := TempPostData;

            // Set the "client" parameter to the TCEFUrlRequestClientComponent.Client property
            // to use the TCEFUrlRequestClientComponent events.
            // The "requestContext" parameter can be nil to use the global request context.
            TCefUrlRequestRef.New(TempRequest, CEFUrlRequestClientComponent1.Client, nil);
          end;
      end;
  finally
    TempElement  := nil;
    TempPostData := nil;
    TempRequest  := nil;
  end;
end;

procedure TURLRequestFrm.CEFUrlRequestClientComponent1DownloadData(Sender: TObject; const request: ICefUrlRequest; data: Pointer; dataLength: NativeUInt);
begin
  try
    if FClosing then
      request.Cancel
     else
      if FSendingGET then
        begin
          if (data <> nil) and (dataLength > 0) then
            FMemStream.WriteBuffer(data^, dataLength);
        end;
  except
    on e : exception do
      if CustomExceptionHandler('TURLRequestFrm.CEFUrlRequestClientComponent1DownloadData', e) then raise;
  end;
end;

procedure TURLRequestFrm.CEFUrlRequestClientComponent1DownloadProgress(Sender: TObject; const request: ICefUrlRequest; current, total: Int64);
begin
  if FClosing then
    request.Cancel
   else
    if FSendingGET then
      begin
        if (total > 0) then
          StatusBar1.Panels[0].Text := 'Downloading : ' + inttostr(round((current / total) * 100)) + ' %'
         else
          StatusBar1.Panels[0].Text := 'Downloading : ' + inttostr(current) + ' bytes';
      end;
end;

procedure TURLRequestFrm.CEFUrlRequestClientComponent1RequestComplete(Sender: TObject; const request: ICefUrlRequest);
begin
  FBusy := False;

  // Use request.response here to get a ICefResponse interface with all the response headers, status, error code, etc.

  if FClosing then
    begin
      FCanClose := True;
      PostMessage(Handle, WM_CLOSE, 0, 0);
    end
   else
    if (request <> nil) and (request.RequestStatus = UR_SUCCESS) then
      PostMessage(Handle, URLREQUEST_SUCCESS, 0, 0)
     else
      PostMessage(Handle, URLREQUEST_ERROR, 0, request.RequestError);
end;

procedure TURLRequestFrm.URLRequestSuccessMsg(var aMessage : TMessage);
var
  TempMessage : string;
begin
  if FSendingGET then
    begin
      TempMessage := 'Download complete!';
      SaveStreamToFile;
    end
   else
    if FSendingPOST then
      TempMessage := 'Parameters sent!';

  StatusBar1.Panels[0].Text := TempMessage;
  showmessage(TempMessage);

  GETGbx.Enabled  := True;
  POSTGbx.Enabled := True;
  FSendingGET     := False;
  FSendingPOST    := False;
end;

procedure TURLRequestFrm.URLRequestErrorMsg(var aMessage : TMessage);
var
  TempMessage : string;
begin
  TempMessage               := 'Error code : ' + inttostr(aMessage.lParam);
  StatusBar1.Panels[0].Text := TempMessage;
  showmessage(TempMessage);

  GETGbx.Enabled  := True;
  POSTGbx.Enabled := True;
  FSendingGET     := False;
  FSendingPOST    := False;
end;

procedure TURLRequestFrm.SaveStreamToFile;
begin
  try
    FMemStream.SaveToFile(SaveDialog1.FileName);
    FMemStream.Clear;
  except
    on e : exception do
      if CustomExceptionHandler('TURLRequestFrm.SaveStreamToFile', e) then raise;
  end;
end;

procedure TURLRequestFrm.SendPostReqBtnClick(Sender: TObject);
var
  TempURL : string;
begin
  TempURL := trim(PostURLEdt.Text);

  if (length(TempURL) > 0) then
    begin
      FPendingURL               := TempURL;
      GETGbx.Enabled            := False;
      POSTGbx.Enabled           := False;
      StatusBar1.Panels[0].Text := 'Sending...';
      FMemStream.Clear;

      FSendingPOST := True;
      FSendingGET  := False;

      // TCEFUrlRequestClientComponent.AddURLRequest will trigger the
      // TCEFUrlRequestClientComponent.OnCreateURLRequest event in the right
      // thread where you can create your custom requests.
      CEFUrlRequestClientComponent1.AddURLRequest;
    end;
end;

end.