How to make a request to a REST API from Delphi
To make HTTP requests in Delphi to an API like Verifacti's, you can use the following code.
uses
System.SysUtils, System.Classes, System.Net.HttpClient, System.Net.URLClient;
procedure CreateInvoice;
var
HttpClient: TNetHTTPClient;
Response: IHTTPResponse;
JSONData: TStringStream;
URL: string;
begin
URL := 'https://api.verifacti.com/verifactu/create';
HttpClient := TNetHTTPClient.Create(nil);
try
HttpClient.CustomHeaders['Authorization'] := 'Bearer <API_KEY>';
HttpClient.ContentType := 'application/json';
JSONData := TStringStream.Create(
'{' +
'"serie": "A",' +
'"numero": "234634",' +
'"fecha_expedicion": "02-12-2024",' +
'"tipo_factura": "F1",' +
'"descripcion": "Descripcion de la operacion",' +
'"nif": "A15022510",' +
'"nombre": "Nombre cliente",' +
'"lineas": [{' +
'"base_imponible": "200",' +
'"tipo_impositivo": "21",' +
'"cuota_repercutida": "42"' +
'}],' +
'"importe_total": "242"' +
'}',
TEncoding.UTF8
);
try
Response := HttpClient.Post(URL, JSONData);
if Response.StatusCode = 200 then
WriteLn('Success: ' + Response.ContentAsString())
else
WriteLn('Error: ' + Response.StatusCode.ToString);
finally
JSONData.Free;
end;
finally
HttpClient.Free;
end;
end;These units are part of Delphi's standard RTL and are available in Delphi versions that support TNetHTTPClient (typically Delphi XE8 and later)
Integration example with WinHttpRequest
If you prefer to use WinHttpRequest in Delphi, it can be done as follows:
uses
ComObj, SysUtils, ActiveX;
procedure CreateInvoiceWithWinHttp;
var
WinHttp: OleVariant;
URL, APIKey, JSONData, Response: string;
begin
CoInitialize(nil);
try
URL := 'https://api.verifacti.com/verifactu/create';
APIKey := '<API_KEY>';
JSONData := '{' +
'"serie": "A",' +
'"numero": "234634",' +
'"fecha_expedicion": "02-12-2024",' +
'"tipo_factura": "F1",' +
'"descripcion": "Descripcion de la operacion",' +
'"nif": "A15022510",' +
'"nombre": "Nombre cliente",' +
'"lineas": [{' +
'"base_imponible": "200",' +
'"tipo_impositivo": "21",' +
'"cuota_repercutida": "42"' +
'}],' +
'"importe_total": "242"' +
'}';
WinHttp := CreateOleObject('WinHttp.WinHttpRequest.5.1');
WinHttp.Open('POST', URL, False);
WinHttp.SetRequestHeader('Authorization', 'Bearer ' + APIKey);
WinHttp.SetRequestHeader('Content-Type', 'application/json');
WinHttp.Send(JSONData);
Response := WinHttp.ResponseText;
WriteLn('Response: ' + Response);
finally
CoUninitialize;
end;
end;How to attach the QR to the invoice in Delphi
To embed a QR code in a PDF, you can use libraries such as:
- SynPDF (part of Synopse mORMot)
- Debenu Quick PDF
- Gnostice PDF Toolkit
Example with SynPDF:
uses
SynPDF;
procedure AgregarQRAlPDF;
var
Doc: TPdfDocumentGDI;
Page: TPdfPage;
QRBitmap: TBitmap;
begin
Doc := TPdfDocumentGDI.Create;
try
Page := Doc.AddPage;
QRBitmap := TBitmap.Create;
try
// Aquí se cargaría la imagen del QR en QRBitmap
Page.RenderDraw(QRBitmap, 100, 100, 200, 200);
finally
QRBitmap.Free;
end;
Doc.SaveToFile('FacturaConQR.pdf');
finally
Doc.Free;
end;
end;How to generate a QR in Delphi
You can use the following libraries to generate QR codes in Delphi:
- ZXing.Delphi (an adaptation of the ZXing library for Delphi)
- DelphiZXingQRCode (another useful implementation for QR codes)
Example with DelphiZXingQRCode:
uses
DelphiZXingQRCode, Vcl.Graphics;
procedure GenerarQR;
var
QRCode: TDelphiZXingQRCode;
Bitmap: TBitmap;
begin
QRCode := TDelphiZXingQRCode.Create;
try
QRCode.Data := 'https://verifacti.com';
QRCode.Encoding := TQRCodeEncoding.qrAuto;
Bitmap := TBitmap.Create;
try
Bitmap.SetSize(QRCode.Rows, QRCode.Columns);
QRCode.DrawBitmap(Bitmap);
Bitmap.SaveToFile('QRFactura.bmp');
finally
Bitmap.Free;
end;
finally
QRCode.Free;
end;
end;