Objective-C

Async Methods Returning an Object

See more Async Examples

Demonstrates how to call an asynchronous method that returns an object. This example reads email from a POP3 server using the Async versions of the Chilkat methods. Objective-C

#import <CkoMailMan.h>
#import <CkoTask.h>
#import <CkoEmail.h>

BOOL success = NO;

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

success = NO;

CkoMailMan *mailman = [[CkoMailMan alloc] init];

// Set the POP3 server's hostname
mailman.MailHost = @"pop.example.com";

// Set the POP3 login/password and any other requirements..
mailman.PopUsername = @"myLogin";
mailman.PopPassword = @"myPassword";
mailman.PopSsl = YES;
mailman.MailPort = [NSNumber numberWithInt:995];

// Connect to the POP3 server:
CkoTask *task = [mailman Pop3BeginSessionAsync];
if (mailman.LastMethodSuccess == NO) {
    NSLog(@"%@",mailman.LastErrorText);
    return;
}

// Start the background task.
success = [task Run];
if (!success) {
    NSLog(@"%@",task.LastErrorText);

    return;
}

// Wait for the POP3 connect task to finish.
// The YES/NO returned by Wait applies to the Wait method call, not the task.
int maxWaitMs = 30000;
success = [task Wait: [NSNumber numberWithInt: maxWaitMs]];
if (!success || ([task.StatusInt intValue] != 7) || (task.TaskSuccess != YES)) {
    if (!success) {
        // The task.LastErrorText applies to the Wait method call.
        NSLog(@"%@",task.LastErrorText);
    }
    else {
        // The ResultErrorText applies to the underlying task method call (i.e. the Pop3BeginSession)
        NSLog(@"%@",task.Status);
        NSLog(@"%@",task.ResultErrorText);
    }

    return;
}

// Get the number of messages in the mailbox.
task = [mailman GetMailboxCountAsync];

// To keep the example short, we'll skip handling failures.
// The failures would be handled in the same way as shown above.

success = [task Run];
success = [task Wait: [NSNumber numberWithInt: maxWaitMs]];
int numMessages = [[task GetResultInt] intValue];

if (numMessages == 0) {
    return;
}

CkoEmail *email = [[CkoEmail alloc] init];

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

    task = [mailman FetchByMsgnumAsync: [NSNumber numberWithInt: i]];
    if (mailman.LastMethodSuccess == NO) {
        NSLog(@"%@",mailman.LastErrorText);
        return;
    }

    success = [task Run];
    success = [task Wait: [NSNumber numberWithInt: maxWaitMs]];
    if (!success || ([task.StatusInt intValue] != 7) || (task.TaskSuccess != YES)) {
        if (!success) {
            // The task.LastErrorText applies to the Wait method call.
            NSLog(@"%@",task.LastErrorText);
        }
        else {
            // The ResultErrorText applies to the underlying task method call (i.e. the FetchByMsgnum)
            NSLog(@"%@",task.Status);
            NSLog(@"%@",task.ResultErrorText);
        }

        return;
    }

    // Each Chilkat object that can be a return value of an asynchronous task will
    // have a method named LoadTaskResult.  The object returned in the underlying
    // asynchronous method call is retrieved by calling LoadTaskResult. 

    // To say it another way: The application will provide a pre-existing object of
    // the desired return type (in this case it is an email object).  This object is
    // loaded by calling LoadTaskResult.  

    success = [email LoadTaskResult: task];

    if (!success) {
        NSLog(@"%@",email.LastErrorText);
        return;
    }
    else {
        NSLog(@"%@%@%@%@",email.From,@": ",email.Subject,@"\n");
    }

}