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Simple Ajax Chat: Auto-Clear Chats

This tutorial explains how to hook up automatic clearing of chat messages with my WordPress plugin, Simple Ajax Chat. Note that this tutorial is for the free version of SAC.

Tip: The Pro version of Simple Ajax Chat supports auto-clear chats without any additional code. Learn more ▸

Auto-clear chat messages

To automatically clear/truncate chats every thirty minutes, add the following to your theme’s functions.php file:

// define SAC auto-clear interval
function sac_truncate_chats_interval($interval) {
	return 'thirty_minutes';
add_filter('sac_truncate_chats_interval_filter', 'sac_truncate_chats_interval');

SAC also includes the following built-in intervals:

  • sixty_minutes
  • thirty_minutes
  • three_minutes
  • thirty_seconds

So you can edit the return value as needed, or add your own interval. Once an interval has been defined via your functions file, SAC automatically will reset the chat box. So if you never define an interval, SAC never will auto-clear messages.

Disabling auto-clear

If you define an interval and later change your mind, you can disable the auto-clear functionality by uninstalling and reinstalling the plugin, or use a cron plugin to manually delete the SAC cron interval. Also make sure to remove the interval definition, which we added in the previous section.

Going further

To go further, SAC also includes an action hook that fires whenever the chats are auto-cleared using WP Cron:


So for example, I use this hook for the following function:

// auto-clear chats notification
function sac_truncate_chats_notify($time, $truncate, $insert) { 
	$email   = get_bloginfo('admin_email');
	$subject = 'Cron Truncate Chatz';
	$message  = 'Time: '     . $time     . "\n";
	$message .= 'Truncate: ' . $truncate . "\n";
	$message .= 'Insert: '   . $insert   . "\n";
	wp_mail($email, $subject, $message);
add_action('sac_truncate_chats_action', 'sac_truncate_chats_notify', 10, 3);

By adding that snippet to my theme’s functions.php, I receive an email each time the chats are cleared. It helps me to keep an eye on the live SAC Demo.

Changing intervals

If you need to change the cron interval, from say thirty_minutes to sixty_minutes or whatever, deactivate/reactivate the plugin and/or use a cron plugin to manually remove/change the interval as needed. That is, just swapping out the interval in functions.php isn’t enough — you need to remove the existing interval and then deactivate/reactivate the plugin to register the new interval.

Bonus tip

SAC also includes a hook for each chat message, so you can do stuff whenever someone leaves a chat:


That hook can be used like this, for example:

// chat message notifications
function sac_log_requests($sac_user_name, $sac_user_text, $sac_user_url) { 
	$site    = get_bloginfo('name');
	$email   = get_bloginfo('admin_email');
	$subject = 'New Chat Message at '. $site;
	$message  = 'Username: ' . $sac_user_name . "\n";
	$message .= 'Message: '  . $sac_user_text . "\n";
	$message .= 'User URL: ' . $sac_user_url  . "\n";
	wp_mail($email, $subject, $message);
add_action('sac_process_chat', 'sac_log_requests', 10, 3);

When added to your theme’s functions.php file, this snippet will send an email alert containing the username, chat message, and user URL (if any) for each chat message.

Just some examples of cool things you can do with Simple Ajax Chat :)

Note: in older versions of SAC, the hook name is sac_process_chat_action.

★ New Pro version of Simple Ajax Chat! Check out SAC Pro ▸

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