Pascal (Lazarus/Delphi)

Get Individual Photo Info

See more Facebook Examples

Assuming we have the ID of a Photo, this example demonstrates how to retrieve the photo information and parse the JSON. 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.StringBuilder,
  Chilkat.JsonObject;

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

procedure RunDemo;
var
  success: Boolean;
  oauth2: TOAuth2;
  rest: TRest;
  photoId: string;
  sbPath: TStringBuilder;
  responseJson: string;
  json: TJsonObject;
  canDelete: Boolean;
  height: Integer;
  width: Integer;

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...
  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);

  //  Assumes we've already obtained a Photo ID.
  photoId := '10210199026347451';

  sbPath := TStringBuilder.Create;
  sbPath.Append('/v2.7/');
  sbPath.Append(photoId);

  //  Select the fields we want.
  //  This example will select many of the possible fields.
  //  See https://developers.facebook.com/docs/graph-api/reference/photo/
  rest.AddQueryParam('fields','id,album,can_delete,can_tag,from,height,width,images,link,name,name_tags,picture,place,target');

  responseJson := rest.FullRequestNoBody('GET',sbPath.GetAsString());
  if (rest.LastMethodSuccess <> True) then
    begin
      WriteLn(rest.LastErrorText);
      Exit;
    end;

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

  //  Show the JSON in human-readable format.
  WriteLn(json.Emit());

  //  A sample response is shown below.
  //  Demonstrate how to parse values from the JSON.
  WriteLn('Album name: ' + json.StringOf('album.name'));
  canDelete := json.BoolOf('can_delete');
  WriteLn('Can Delete: ' + canDelete);
  WriteLn('From Name: ' + json.StringOf('from.name'));
  height := json.IntOf('height');
  width := json.IntOf('width');
  WriteLn('Dimensions: ' + width + 'x' + height);
  WriteLn('First Image Source: ' + json.StringOf('images[0].source'));

  //  A sample JSON response is shown here.  
  //  { 
  //    "id": "10210199026347451",
  //    "album": { 
  //      "created_time": "2009-10-19T00:06:46+0000",
  //      "name": "Timeline Photos",
  //      "id": "1237223526054"
  //    },
  //    "can_delete": true,
  //    "can_tag": true,
  //    "from": { 
  //      "name": "Matt Smith",
  //      "id": "10224048320139890"
  //    },
  //    "height": 120,
  //    "width": 120,
  //    "images": [
  //      { 
  //        "height": 120,
  //        "source": "https:\/\/scontent.xx.fbcdn.net\/v\/t1.0-9\/14462791_10210199026347451_7830642117574407060_n.jpg?oh=a7f9ed10cf9cd81a82adeb541c60e2e2&oe=58ABB195",
  //        "width": 120
  //      }
  //    ],
  //    "link": "https:\/\/www.facebook.com\/photo.php?fbid=10210199026347451&set=a.1237223526054.2038240.1093202869&type=3",
  //    "name": "Ignore my posts -- I'm doing some testing for Facebook related programming...",
  //    "picture": "https:\/\/scontent.xx.fbcdn.net\/v\/t1.0-9\/14462791_10210199026347451_7830642117574407060_n.jpg?oh=a7f9ed10cf9cd81a82adeb541c60e2e2&oe=58ABB195"
  //  }
  //  


  oauth2.Free;
  rest.Free;
  sbPath.Free;
  json.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.