Pascal (Lazarus/Delphi)

Iterate Pages in Feed

See more Facebook Examples

Demonstrates how to read the next page in the user's Facebook feed, and iterates through all of the pages in the Facebook feed. Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.OAuth2,
  Chilkat.Rest,
  Chilkat.Url,
  Chilkat.JsonObject;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  oauth2: TOAuth2;
  rest: TRest;
  responseJson: string;
  json: TJsonObject;
  nextUrl: TUrl;
  nextUrlStr: string;

begin
  success := False;

  //  This example requires the Chilkat API to have been previously unlocked.
  //  See Global Unlock Sample for sample code.

  //  This example assumes a previously obtained an access token
  oauth2 := TOAuth2.Create;
  oauth2.AccessToken := 'FACEBOOK-ACCESS-TOKEN';

  rest := TRest.Create;

  //  Connect to Facebook and send the following GET request:
  success := rest.Connect('graph.facebook.com',443,True,True);
  if (success <> True) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  //  Provide the authentication credentials (i.e. the access key)
  rest.SetAuthOAuth2(oauth2);

  //  Gets the 1st page in the user's feed.
  responseJson := rest.FullRequestNoBody('GET','/v2.7/me/feed');
  if (rest.LastMethodSuccess <> True) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

  json := TJsonObject.Create;
  json.EmitCompact := False;
  json.Load(responseJson);

  //  See Parsing the Facebook User Feed for code showing how to parse the JSON feed content.
  //  

  nextUrl := TUrl.Create;

  //  Get the URL for the next page in the feed.
  nextUrlStr := json.StringOf('paging.next');
  while json.LastMethodSuccess = True do
    begin

      WriteLn('Next page URL: ' + nextUrlStr);

      nextUrl.ParseUrl(nextUrlStr);

      //  Prepare for getting the next page in the feed.
      //  We can continue using the same REST object.
      //  If already connected, we'll continue using the existing connection.
      //  Otherwise, a new connection will automatically be made if needed.
      rest.ClearAllQueryParams();
      rest.AddQueryParams(nextUrl.Query);

      responseJson := rest.FullRequestNoBody('GET','/v2.7/me/feed');
      if (rest.LastMethodSuccess <> True) then
        begin
          WriteLn(rest.LastErrorText);
          Exit;
        end;

      json.Load(responseJson);
      //  See Parsing the Facebook User Feed for code showing how to parse the JSON feed content.

      //  Get the URL for the next page.
      nextUrlStr := json.StringOf('paging.next');
    end;

  WriteLn('No more pages in the feed.');


  oauth2.Free;
  rest.Free;
  json.Free;
  nextUrl.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.