(PHP Extension) Async Task Chain

Demonstrates how to combine a sequence of asynchronous tasks into a single task chain to be run in a background thread.

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<?php

// The version number (9_5_0) should match version of the Chilkat extension used, omitting the micro-version number.
// For example, if using Chilkat v9.5.0.48, then include as shown here:
include("chilkat_9_5_0.php");

// All Chilkat classes can be unlocked at once at the beginning of a program
// by calling UnlockBundle.  It requires a Bundle unlock code.
$chilkatGlob = new CkGlobal();
$success = $chilkatGlob->UnlockBundle('Anything for 30-day trial.');
if ($success != true) {
    print $chilkatGlob->lastErrorText() . "\n";
    exit;
}

$mailman = new CkMailMan();

// Set the POP3 server's hostname
$mailman->put_MailHost('pop.someMailServer.com');

// Set the POP3 login/password and any other requirements..
$mailman->put_PopUsername('myLogin');
$mailman->put_PopPassword('myPassword');
$mailman->put_PopSsl(true);
$mailman->put_MailPort(995);

// Connect to the POP3 server:
$success = $mailman->Pop3BeginSession();
if (!$success) {
    print $mailman->lastErrorText() . "\n";
    exit;
}

// Get the number of messages in the mailbox.
$numMessages = $mailman->GetMailboxCount();
if ($numMessages == 0) {
    print 'No email messages in the POP3 mailbox.' . "\n";
    exit;
}

$taskChain = new CkTaskChain();

// Create async task objects to fetch each email message
// by its sequence number

for ($i = 1; $i <= $numMessages; $i++) {

    // task is a CkTask
    $task = $mailman->FetchByMsgnumAsync($i);
    if ($mailman->get_LastMethodSuccess() == false) {
        print $mailman->lastErrorText() . "\n";
        exit;
    }

    // Append each task to the task chain.
    $success = $taskChain->Append($task);
    if (!$success) {
        print $taskChain->lastErrorText() . "\n";
        exit;
    }

}

// At this point, no tasks have actually started running.
// All we've done so far is to create tasks for the work that will be done
// when the task chain is run.

// Start the task chain running in a background thread.
// Each task is run one after the other (on the same background thread) until all tasks have completed.
// The task chain will stop at the first task that fails.
$taskChain->put_StopOnFailedTask(true);
$success = $taskChain->Run();
if (!$success) {
    print $taskChain->lastErrorText() . "\n";
    exit;
}

// The application is now free to do anything else
// while the emails are being downloaded

// For this example, we'll simply sleep and periodically
// check to see if the taskchain if finished. 
while ($taskChain->get_Finished() != true) {

    // Sleep 100 ms.
    $taskChain->SleepMs(100);

}

// A finished task chain could be one that was canceled, aborted, or truly finished.  

// If the task chain "completed", then it ran to completion.  A "completed" task will
// have a StatusInt equal to 7.   If the task finished, but was not completed, then it must've
// been aborted or canceled:
if ($taskChain->get_StatusInt() != 7) {
    print 'Task did not complete.' . "\n";
    print 'task chain status: ' . $taskChain->status() . "\n";
    exit;
}

$email = new CkEmail();

$numTasks = $taskChain->get_NumTasks();
$taskIdx = 0;

while (($taskIdx < $numTasks)) {

    // task is a CkTask
    $task = $taskChain->GetTask($taskIdx);

    // Load the email object with email downloaded by this task.
    $success = $email->LoadTaskResult($task);
    if (!$success) {
        print 'Failed to load email object for task.' . "\n";
    }
    else {
        print $email->from() . '; ' . $email->subject() . "\n";
    }

    $taskIdx = $taskIdx + 1;
}


?>