Delete Variations from Products

delete_variations_based_on_date.php

<?php
function delete_variations(){
	// Lets grab the product type
    	$product_id   = get_the_ID();
	$product_type = WC_Product_Factory::get_product_type( $product_id );

	// Lets skip everything if its not a product.
	if( $product_type == false ) return;

    	// Lets make sure we are working with registrations
	if( $product_type == 'registrations') {
	    // Grab the ID
		$parent   = wc_get_product( $product_id );
		// Pull children or variations of parent
		$children = $parent->get_children();
		//
		foreach ( $children as $child ) {
			$dates = json_decode( get_post_meta( $child, 'attribute_dates', true ) );
			$today = strtotime( date( 'Y-m-d' ) );
			if ( $dates->type == 'range' ) {
				$first_date = strtotime( $dates->dates[0] );
				if ( $first_date < $today ) {
					deleteProduct( $child, true );
				}
			} elseif ( $dates->type == 'single' ) {
				$date = strtotime( $dates->date );
				if ( $date < $today ) {
					deleteProduct( $child, true );
				}
			}
		}
	}
}
add_action( "template_redirect", "delete_variations" );

This will delete a variation from the parent product if conditions aren't met. This instance is pulling dates used by the WooCommerce registration plugin as it does not drop off expired dates.

deleteProduct function referenced here:
https://gist.github.com/mtruitt/8e2fae133ef15706bb4728d11d9e9dcf