(Delphi ActiveX) Xero Download Attachment for an Item (such as an Invoice)

Demonstrates how to download a particular attachment for a particular Xero item.

For more information, see https://developer.xero.com/documentation/api/attachments#GET

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
http: TChilkatHttp;
jsonToken: TChilkatJsonObject;
success: Integer;
url: WideString;
bd: TChilkatBinData;

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

http := TChilkatHttp.Create(Self);

jsonToken := TChilkatJsonObject.Create(Self);
success := jsonToken.LoadFile('qa_data/tokens/xero-access-token.json');
if (success = 0) then
  begin
    Memo1.Lines.Add(jsonToken.LastErrorText);
    Exit;
  end;

http.AuthToken := jsonToken.StringOf('access_token');

// Replace the value here with an actual tenant ID obtained from this example:
// Get Xero Tenant IDs
http.SetRequestHeader('Xero-tenant-id','83299b9e-5747-4a14-a18a-a6c94f824eb7');

http.Accept := 'application/json';

// The example to list Xero attachments shows how to get attachment information.
// Here's a sample JSON response obtained form listing attachments:
// Your application can get the AttachmentID's and filenames from it.

// {
//   "Id": "24bfbcb9-dec9-4d33-835c-8f165d776766",
//   "Status": "OK",
//   "ProviderName": "Chilkat2222",
//   "DateTimeUTC": "\/Date(1587213296972)\/",
//   "Attachments": [
//     {
//       "AttachmentID": "daf106e2-8634-4349-bfcc-86c1df0793b2",
//       "FileName": "penguins.jpg",
//       "Url": "https://api.xero.com/api.xro/2.0/Invoices/0032f627-3156-4d30-9b1c-4d3b994dc921/Attachments/penguins.jpg",
//       "MimeType": "image/jpg",
//       "ContentLength": 777835
//     }
//   ]
// }

url := 'https://api.xero.com/api.xro/2.0/{$Endpoint}/{$Guid}/Attachments/{$AttachmentId}';

// Endpoint can be Invoices, Receipts, CreditNotes, PurchaseOrders, etc.
http.SetUrlVar('Endpoint','Invoices');

// Guid is the ID of the item, such as the InvoiceID.
http.SetUrlVar('Guid','0032f627-3156-4d30-9b1c-4d3b994dc921');

// AttachmentId is the ID of the particular attachment to be downloaded
http.SetUrlVar('AttachmentId','daf106e2-8634-4349-bfcc-86c1df0793b2');

// Download the attachment data into bd.
bd := TChilkatBinData.Create(Self);
success := http.QuickGetBd(url,bd.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(http.LastErrorText);
    Exit;
  end;

Memo1.Lines.Add('Response Status Code: ' + IntToStr(http.LastStatus));

if (http.LastStatus = 200) then
  begin
    // Success
    // Save to a file..
    success := bd.WriteFile('qa_output/penguines.jpg');
  end
else
  begin
    // Failed.  bd contains error information..
    Memo1.Lines.Add(bd.GetString('utf-8'));
  end;
end;