woocommerce-pos / includes / Sync / Variable_Children.php

Variable_Children.php in WCPOS – Point of Sale (POS) plugin for WooCommerce trunk, at includes/Sync/Variable_Children.php

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1	<?php
2	/**
3	* WCPOS sync read surface.
4	*
5	* @package WCPOS\WooCommercePOS\Sync
6	*/
7
8	namespace WCPOS\WooCommercePOS\Sync;
9
10	/**
11	* Narrows a variable product's advertised child list to what the POS may actually sell.
12	*
13	* # Why
14	*
15	* `product.variations[]` is the client's ONLY discovery list for a variable product: the row
16	* expansion, the POS variations popover, the "Showing N of M" footer and the idle prefetch walk all
17	* read it and nothing else. WooCommerce fills it from `WC_Product_Variable::get_children()`, which
18	* returns every child with `post_status IN ( 'publish', 'private' )` and knows nothing about POS
19	* visibility.
20	*
21	* Every other component that answers "which children exist" already narrows the set — the
22	* variations endpoint refuses to hydrate a hidden or disabled child, {@see Variable_Price_Range}
23	* computes its range from `get_visible_children()`, and the census counts only servable rows. The
24	* parent payload was the one that did not, so a store hiding or disabling a variation got four
25	* components giving three answers:
26	*
27	* - the footer renders "Showing 2 of 3" forever, with no way to reach the third;
28	* - the popover offers a row that cannot be added;
29	* - the row expansion asks for the id, receives a shortfall, prunes it, and asks again on the next
30	* expansion — permanent churn;
31	* - the prefetch walk spends one request per walk on an id the server will never serve.
32	*
33	* Filtering here fixes all four at once, because it fixes the fact they all read.
34	*
35	* # What is filtered
36	*
37	* Two rules, both WooCommerce's own:
38	*
39	* - POS visibility — `online_only` children, per {@see Pos_Visibility}. Ours, and additive: it
40	* changes which records are served, never what a field means.
41	* - Disabled children — `post_status !== 'publish'`. WooCommerce's Enabled checkbox on the
42	* variation metabox writes `post_status = private` when unchecked, and WooCommerce honours that
43	* everywhere a customer can reach (`get_visible_children()`, `get_available_variations()`). A
44	* cashier must not be offered a variation the owner switched off.
45	*
46	* # Ordering
47	*
48	* Registered as a record augmenter at priority 10 — AFTER the revision stamper at 9. The parent's
49	* `_rxdb_revision` therefore stays a hash of the bare wc/v3 bytes, which is what the write path
50	* recomputes from a bare re-read, so narrowing this list cannot perturb optimistic concurrency.
51	* Same ordering {@see Variable_Prices} already relies on when it blanks the parent's price fields.
52	*
53	* # Why round-tripping the narrowed list is safe
54	*
55	* A client's product update layers its resident stored payload, so the narrowed array does travel
56	* back to wc/v3. `variations` is `readonly => true` in WooCommerce's product schema (v2 and v3), so
57	* WooCommerce ignores it on write and no child can be removed by omission. Anything that changes
58	* this class must re-verify that property.
59	*/
60	final class Variable_Children {
61	/**
62	* Narrow `variations[]` on a serialized variable product.
63	*
64	* Non-variable products and payloads without a usable list pass through untouched. The `type`
65	* gate comes first so a page of simple products never pays for a lookup.
66	*
67	* @param mixed $payload Serialized product record.
68	* @param null\|mixed $object Product object, when the lane has one loaded.
69	* @param null\|mixed $request Request context.
70	*/
71	public static function augment_record( $payload, $object = null, $request = null ) {
72	if ( ! \is_array( $payload ) \|\| 'variable' !== ( $payload['type'] ?? '' ) ) {
73	return $payload;
74	}
75	if ( ! isset( $payload['variations'] ) \|\| ! \is_array( $payload['variations'] ) ) {
76	return $payload;
77	}
78
79	$children = array_values( array_filter( array_map( 'intval', $payload['variations'] ) ) );
80	if ( array() === $children ) {
81	return $payload;
82	}
83
84	$payload['variations'] = array_values(
85	array_filter(
86	( new Pos_Visibility() )->filter_visible_children( $children ),
87	static function ( int $id ): bool {
88	return 'publish' === get_post_status( $id );
89	}
90	)
91	);
92
93	return $payload;
94	}
95	}
96