(Delphi ActiveX) Paging User Photos with Cursor

Demonstrates how to iterate over the pages of user photos using a cursor.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
oauth2: TChilkatOAuth2;
rest: TChilkatRest;
success: Integer;
responseJson: WideString;
json: TChilkatJsonObject;
afterCursor: WideString;

begin
// 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 := TChilkatOAuth2.Create(Self);
oauth2.AccessToken := 'FACEBOOK-ACCESS-TOKEN';

rest := TChilkatRest.Create(Self);

// Connect to Facebook.
success := rest.Connect('graph.facebook.com',443,1,1);
if (success <> 1) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;

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

// Indicate that we only want the photos the user has personally uploaded.
rest.AddQueryParam('type','uploaded');

// We could limit the number of photos per page using the "limit" field.
rest.AddQueryParam('limit','20');

// Get the 1st page of photos. (Not the actual image data, but the information about each photo.)
// See https://developers.facebook.com/docs/graph-api/reference/user/photos/ for more information.
responseJson := rest.FullRequestNoBody('GET','/v2.7/me/photos');
if (rest.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(rest.LastErrorText);
    Exit;
  end;

json := TChilkatJsonObject.Create(Self);
json.EmitCompact := 0;
json.Load(responseJson);
Memo1.Lines.Add(json.Emit());

// 
// See Parsing the Facebook User Photos for code showing how to parse the JSON photos content.
// 

// Get the "after" cursor.
afterCursor := json.StringOf('paging.cursors.after');
while json.LastMethodSuccess = 1 do
  begin

    Memo1.Lines.Add('after cursor: ' + afterCursor);

    // Prepare for getting the next page of photos.
    // 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.AddQueryParam('type','uploaded');
    rest.AddQueryParam('limit','20');
    rest.AddQueryParam('after',afterCursor);

    responseJson := rest.FullRequestNoBody('GET','/v2.7/me/photos');
    if (rest.LastMethodSuccess <> 1) then
      begin
        Memo1.Lines.Add(rest.LastErrorText);
        Exit;
      end;

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

    Memo1.Lines.Add(json.Emit());

    // Get the cursor for the next page.
    afterCursor := json.StringOf('paging.cursors.after');
  end;

Memo1.Lines.Add('No more pages of photos.');
end;