Dart Requires Chilkat v11.0.0+

IMAP Read PEC Email of Aruba and Extract the Invoice XML Files

See more Email Object Examples

IMAP Read PEC Email of Aruba and Extract the Invoice XML Files. Dart

import 'package:chilkat/chilkat.dart';

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

  final imap = CkImap();

  // Connect using TLS.
  imap.ssl = true;
  imap.port = 993;
  try {
    imap.connect('imap.example.com');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Authenticate
  try {
    imap.login('email_account_login', 'email_account_password');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Select an IMAP mailbox
  try {
    imap.selectMailbox('Inbox/postacert');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Search for messages having "POSTA CERTIFICATA: Invio File" in the subject.
  final fetchUids = true;
  final messageSet = CkMessageSet();
  try {
    imap.queryMbx('SUBJECT "POSTA CERTIFICATA: Invio File"', fetchUids, messageSet);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  if (messageSet.count < 1) {
    print('No messages found.');
    return;
  }

  // For our example, we'll process only the 1st email in the messageSet.
  // Download the MIME source of the email into a StringBuilder object.
  final email = CkEmail();
  try {
    imap.fetchEmail(false, messageSet.getId(0), messageSet.hasUids, email);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // The email should contain an attached email.
  // The Invoice XML is contained within the attached email.
  final attachedEmail = CkEmail();
  try {
    email.getAttachedEmail(0, attachedEmail);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Get the MIME of the attached email..
  final sbMime = CkStringBuilder();
  attachedEmail.getMimeSb(sbMime);

  // Load it into a Chilkat MIME object.
  final mime = CkMime();
  mime.loadMimeSb(sbMime);

  // Examine the structure of the MIME.
  print(mime.getStructure('text'));

  // The MIME has this structure:
  // multipart/mixed
  //     application/octet-stream
  //     application/octet-stream     <-- This is where the XML is contained.   It is within an opaque signature.
  //     text/plain

  // The 2nd application/octet-stream MIME header looks like this:

  // ------=_Part_329673_-1348225228.1579889273592
  // Content-Type: application/octet-stream; name="SM99999_99aaa.xml.p7m"
  // Content-Transfer-Encoding: base64
  // Content-Disposition: attachment; filename="SM99999_99aaa.xml.p7m"

  // Let's get the binary content of the .p7m
  final bdP7m = CkBinData();
  // Get the 2nd sub-part, at index 1 because index 0 is the 1st sub-part.

  final mimeP7m = CkMime();
  try {
    mime.partAt(1, mimeP7m);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  if (!mime.lastMethodSuccess) {
    print('Failed to get 2nd sub-part. Perhaps the MIME does not have a 2nd sub-part?');
    return;
  }

  mimeP7m.getBodyBd(bdP7m);

  // Verify the signature, which also extracts the content contained within the opaque signature.
  final crypt = CkCrypt2();
  try {
    crypt.opaqueVerifyBd(bdP7m);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // The bdP7m now contains the Invoice XML.
  // Load it into an XML object.
  final xml = CkXml();
  xml.loadBd(bdP7m, true);

  print(xml.getXml());

  // We have XML such as the following:
  // 
  // <?xml version="1.0" encoding="windows-1252"?>
  // <?xml-stylesheet type="text/xsl" href="fatturapa_v1.2.xsl"?>
  // <p:FatturaElettronica versione="FPR12" xmlns:ds="http://www.w3.org/2000/09/xmldsig#" 
  //     xmlns:p="http://ivaservizi.agenziaentrate.gov.it/docs/xsd/fatture/v1.2" 
  //     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  //     <FatturaElettronicaHeader>
  // 	...
  //     </FatturaElettronicaHeader>
  //     <FatturaElettronicaBody>
  // 	...
  //     </FatturaElettronicaBody>
  // </p:FatturaElettronica>

  // Use this online tool to generate parsing code from sample XML: 
  // Generate Parsing Code from XML

  print('success.');
}