php snippet breaks down the site - php

Question

My products have a custom meta 'wccaf_virtual_quantity'. Now I want to calculate and add another custom meta 'actual_stock'. Value of 'actual_stock' = stock - wccaf_virtual_quantity
The code I am trying breaks down my site It gives error of 'The site is experiencing technical difficulties. Please check your site admin email inbox for instructions.' while accessing admin panel. but when I disable the code from the database and check the products table for 'actual_stock', I can see the values of 'actual_stock' are updated.
That means the code works as it should but it breaks down the site in process.
I have tried adding following code to functions.php. I am adding php snippet using 'Code Snippets' plugin
$args = array(
'post_type' => 'product',
'posts_per_page' => -1,
);
$products_array = get_posts($args);
if (!empty($products_array)) {
// loop through each product
foreach ($products_array as $product)
{
update_actual_stock($product->ID);
}
}
function update_actual_stock($post_id) {
$post_type = get_post_type($post_id);
if ($post_type == 'product') {
$product = wc_get_product($post_id);
$virtual_stock = get_post_meta( $post_id,
'wccaf_virtual_quantity', true );
$visible_stock = $product->get_stock_quantity();
$actual_quantity = $visible_stock - $virtual_stock;
update_post_meta( $post_id, 'actual_stock',$actual_quantity);
}
}
Please check what am I doing wrong.

Answer 1

Why do you have to run the function on every request?
Off-course, your code can kill your server, its being triggered for every request either admin or front-end, and its queries and loops through all posts then update all product post,
You should hook it somewhere, like when post is created/updated
checkout save_post function
//Your function to update the meta
function update_actual_stock($post_id) {
$post_type = get_post_type($post_id);
if ($post_type == 'product') {
$product = wc_get_product($post_id);
$virtual_stock = get_post_meta( $post_id, 'wccaf_virtual_quantity', true );
$visible_stock = $product->get_stock_quantity();
$actual_quantity = $visible_stock - $virtual_stock;
update_post_meta( $post_id, 'actual_stock',$actual_quantity);
}
}
// hook it on 'save_post' action hook so it only updates meta of specific post if its updated/created
function _update_blabla_meta( $post_id ) {
update_actual_stock($post_id)
}
add_action( 'save_post', '_update_blabla_meta' );
if you need your function to run after order is place you have to hook it on woocommerce_checkout_order_processed, there are three parameter being pass on that action do_action( 'woocommerce_checkout_order_processed', $order_id, $posted_data, $order ); for you to grab which post to update
check the code here https://docs.woocommerce.com/wc-apidocs/source-class-WC_Checkout.html#1120
EDIT....
This should achieve what you want, or simply modify it to suit your needs;
//run meta update on products only after order is place
add_action( 'woocommerce_checkout_order_processed', function($order_id) {
$order = wc_get_order( $order_id ); // get the order from ID
$items = $order->get_items(); // get order items
//Loop through order each items
foreach ( $items as $item ) {
$porduct_id = $item->get_product_id(); //get the product ID from order item
$virtual_stock = get_post_meta( $porduct_id, 'wccaf_virtual_quantity', true ); // get your own meta value
$visible_stock = get_post_meta( $porduct_id, '_stock', true ); // get the product current stock count
$actual_quantity = $visible_stock - $virtual_stock;
update_post_meta( $porduct_id, 'actual_stock', $actual_quantity); // Update your own meta
}
});