LazyCron

When LazyCron is installed and autoloaded, it hooks ProcessPageView::finished and runs pending jobs after the page response has been sent. This keeps cron overhead from slowing down the visitor experience.

If the module's CLI mode only setting is enabled (cliOnly), LazyCron does not run during HTTP requests. You then trigger it manually with php index.php lazycron run or with a system cron job such as:

wget --quiet --no-cache -O - https://www.example.com/ > /dev/null

In a module

Attach a hook to one of the interval methods in your module's init() or ready() method:

public function init() {
    $this->addHook('LazyCron::everyDay', $this, 'cleanupOldLogs');
}

public function cleanupOldLogs(HookEvent $event) {
    $secondsElapsed = $event->arguments(0);
    // run daily cleanup
}

In templates or site hooks

Use $wire->addHook() (or wire()->addHook()) with a globally defined callback function:

$wire->addHook('LazyCron::every30Minutes', null, 'myCronJob');

function myCronJob(HookEvent $event) {
    $secondsElapsed = $event->arguments(0);
    // runs roughly every 30 minutes
}

All interval methods are hookable. The first time LazyCron runs it fires every interval to establish baselines, so expect all hooks to execute once immediately after installation.

execute()

execute(): void

Run all pending LazyCron jobs immediately. This is called automatically after page views unless cliOnly is enabled. You can also call it directly if you have a reference to the module instance.

$modules->get('LazyCron')->execute();

getTimeFuncs()

getTimeFuncs(): array

Return all supported interval methods keyed by seconds.

$funcs = $modules->get('LazyCron')->getTimeFuncs();
// [30 => 'every30Seconds', 60 => 'everyMinute', ...]

getTimeFuncName($seconds)

getTimeFuncName(int $seconds): string

Return the interval method whose period is closest to the given number of seconds.

$name = $modules->get('LazyCron')->getTimeFuncName(400); // 'every5Minutes'

getTimeFuncSeconds($timeFuncName)

getTimeFuncSeconds(string $timeFuncName): int

Return the number of seconds associated with an interval method name. The method name is case-sensitive.

$seconds = $modules->get('LazyCron')->getTimeFuncSeconds('everyHour'); // 3600

getCliCommands()

getCliCommands(): array

Return the CLI commands provided by this module (used by ProcessWire's CLI router).

$commands = $modules->get('LazyCron')->getCliCommands();
// ['run' => 'Run pending attached LazyCron jobs', 'list' => 'List current attached jobs']

executeCli(array $args)

executeCli(array $args): void

Dispatch a CLI command. Usually called by php index.php lazycron <command>.

$modules->get('LazyCron')->executeCli(['run']);

LazyCron registers the lazycron CLI namespace:

# Run pending jobs immediately
php index.php lazycron run

# List hooks currently attached to LazyCron intervals
php index.php lazycron list

When cliOnly is enabled, run is the only way (other than a real cron job hitting the site) to trigger LazyCron jobs.

As a convenience, LazyCron will include any PHP file placed in /site/templates/LazyCron/ whose name matches an interval method. For example, /site/templates/LazyCron/everyDay.php runs with the everyDay interval. All API variables ($pages, $config, etc.) are extracted into the file's scope.

// /site/templates/LazyCron/everyDay.php
$old = $pages->find('template=temp, created<' . (time() - 86400));
$pages->delete($old);

This is useful for quick, template-level cron jobs that do not warrant a custom module.

• LazyCron uses a lock file (/site/assets/cache/LazyCronLock.cache) to prevent concurrent runs. The lock expires automatically after one hour if a previous run failed fatally.
• State is stored in /site/assets/cache/LazyCron.cache.
• Intervals are approximate when triggered by page views; use a real cron job or the CLI for precise scheduling.
• The callback receives the actual elapsed seconds as its first argument.
• LazyCron is an autoload module and is obtained with $modules->get('LazyCron').
• Source file: wire/modules/System/LazyCron/LazyCron.module.