Dart Requires Chilkat v11.0.0+

IMAP Search with THREAD Semantics

See more IMAP Examples

Demonstrates how to search an IMAP mailbox and return message numbers grouped together in parent/child relationships based on which messages are replies to others. 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 to your IMAP server and authenticate..
  imap.ssl = true;
  imap.port = 993;
  try {
    imap.connect('imap.mail.us-west-2.awsapps.com');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  try {
    imap.login('myLogin', 'myPassword');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

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

  // Search for all message having the letter 'a' somewhere in the Subject,
  // and return the messages as JSON.
  final json = CkJsonObject();
  try {
    imap.queryThread('REFERENCES', 'SUBJECT a', true, json);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // The IMAP server will return a raw response with a format such as this:  (2)(3 6 (4 23)(44 7 96))

  // In tree form, it's like this:
  // 
  //             -- 2
  //             -- 3
  //                 \-- 6
  //                    |-- 4
  //                    |      \-- 23
  //                    |
  //                    |-- 44
  //                               \-- 7
  //                                       \-- 96
  // 

  // It means there are 2 main threads returned, but the 2nd thread splits into two sub-threads.
  // In total, we can think of it as 3 threads -- 2 main threads (with no parents) and one sub-thread w/ a parent.
  // 
  // - The 1st thread contains the message 2, and has no parent thread.
  // - The 2nd thread contains the messages 3, 6, 4, 23, and has no parent thread.
  // - The 3rd thread contains the messages 44, 7, 96 and the parent thread is message 6.
  // 

  // (Yes, this is all highly confusing...)

  // Chilkat will return the above sample response as JSON that looks like this:

  // {
  //   "threads": [
  //     [2],
  //     [3, 6, [4, 23], [44, 7, 96]]
  //   ]
  // }
  // 

  // Use this online tool to generate parsing code from sample JSON: 
  // Generate Parsing Code from JSON
  // In this case, the online tool can help you get a feel for how to write the JSON parsing code..

  final numThreads = json.sizeOfArray('threads');
  print('The total number of top-level threads is $numThreads');

  // Let's say we wanted to get the messages in the thread 3, 6, 4, 23.
  // We always follow the 1st branch to the bottom, ignoring the other branches.
  // For example, if we had  [3, 5, [4, 23, [55, 56, 57], [68, 69]], [44, 7, 96]]
  // then the thread would be 3, 5, 4, 43, 55, 56, 57

  // For testing, let's substitute the response from the IMAP server with this sample:
  json.load('{"threads": [[2], [3, 5, [4, 23, [55, 56, 57], [68, 69]], [44, 7, 96]]]}');

  // Begin with the 2nd top-level thread, which is at index 1.
  print('Following the 2nd top level thread...');
  var arr = json.arrayOf('threads[1]');
  var threadSize = arr.size;
  var i = 0;
  while (i < threadSize) {
    // Do we have an array or integer at this position?
    if (arr.typeAt(i) == 4) {
      // This is a sub-array.
      final subArr = arr.arrayAt(i);

      // Follow the sub-array starting at the 1st position..
      arr = subArr;
      i = 0;
      threadSize = arr.size;
    } else {
      // Must be a single integer.
      print(arr.intAt(i));
      i++;
    }
  }

  // The output is:
  // 
  // Following the 2nd top level thread...
  // 3
  // 5
  // 4
  // 23
  // 55
  // 56
  // 57
}