wp_schedule_event / cron_schedules - custom recurrence time not working in Plugin

Question

I am trying to add custom intervals for the WP cron in a plugin. It run with "hourly", "daily" default recurrence time. It dont' run when I add my own custom recurrence time for the function wp_schedule_event.

I want to execute a function every X hours (defined by users).

Thanks.

Here is the code:

<?php
/*
Plugin Name: Test Cron
Description: Plugin to Test Cron Jobs.
Version: 1.00
*/
class WP_TestCron {
    function __construct()
    {
        register_activation_hook(__FILE__, array($this, 'TestCron_cron_activate'));
        register_deactivation_hook(__FILE__, array($this, 'TestCron_cron_deactivate'));
        add_filter('cron_schedules', array($this, 'TestCron_cron_update_schedules'));
        add_action('TestCron_cron_eventOne', array($this, 'TestCron_cron_fct'));
        add_action('TestCron_cron_eventTwo', array($this, 'TestCron_cron_fct'));
    }

    function TestCron_cron_activate() 
    {
        // Run => In Schedule Cronjobs 
        if (!wp_next_scheduled('TestCron_cron_eventOne')) { wp_schedule_event(time(), 'hourly', 'TestCron_cron_eventOne'); }

        // Dont't Run => Not in Schedule Cronjobs 
        if (!wp_next_scheduled('TestCron_cron_eventTwo')) { wp_schedule_event(time(), 'in_per_minute', 'TestCron_cron_eventTwo'); }
    }

    function TestCron_cron_deactivate() 
    {
        wp_clear_scheduled_hook('TestCron_cron_eventOne');
        wp_clear_scheduled_hook('TestCron_cron_eventTwo');
    }

    function TestCron_cron_update_schedules() 
    {
        return array(
            'fively' => array('interval' => 300, 'display' => 'Once in Five minutes'),
            'in_per_minute' => array('interval' => 60, 'display' => 'In every minute'),
            'in_per_ten_minute' => array('interval' => 60 * 10, 'display' => 'Once in Ten minutes'),
            'three_hourly' => array('interval' => 60 * 60 * 3,  'display' => 'Once in three hours')
        );  
    }

    function TestCron_cron_fct() 
    {
        $testCcron_post = array();
        $testCcron_post['post_title'] = 'Cron Update - '.date('d/m/y \a\t h:i A');
        $testCcron_post['post_content'] = 'WP-Cron job is working!';
        $testCcron_post['post_status'] = 'publish';
        $testCcron_post['post_author'] = 1;
        $testCcron_post['post_category'] = array(1);

        wp_insert_post( $testCcron_post );  
    }   
}

if (is_admin()) $wpTC = new WP_TestCron();

?>

Answer 1

WP-Cron doesn't run in the admin scope - remove your if ( is_admin() ) condition.

Answer 2

I would also suggest not overwriting existing schedules.

The proper form would be to do:

function filter_cron_schedules( $schedules ) {
$schedules['fively'] = array(
    'interval' => 300,
    'display' => __('Once in Five minutes')
);  

$schedules['in_per_minute'] = array(
    'interval' => 60,
    'display' => __('In every minute')
);  

$schedules['in_per_ten_minute'] = array(
    'interval' => 600,
    'display' => __('Once in Ten minutes')
);  

$schedules['three_hourly'] = array(
    'interval' => 10800,
    'display' => __('Once in three hours')
);  
return $schedules;
}

Which would take the existing $schedules, add the 4 new intervals to it, and then return the updated array.

Mind you, I have had some serious problems with cron in class-based plugins before, a recent issue led me to this question.