Blocks: Introduce filter to allow easy addition of hooked blocks

[Bernhard Reiter]

As a follow-up to [56649], it would be good to introduce a filter that allows even easier conditional addition (or removal) of hooked blocks for a given anchor block and relative position.

Something along the following lines:

<?php
function insert_shopping_cart_hooked_block( $hooked_blocks, $position, $anchor_block, $context ) {
        if ( 'after' === $position && 'core/navigation' === $anchor_block && /** $context is header template part **/ ) {
                $hooked_blocks[] = 'mycommerce/shopping-cart';
        }
        return $hooked_blocks;
}
add_filter( 'hooked_block_types', 'insert_shopping_cart_hooked_block', 10, 4 );

Introduce a hooked_block_types filter that allows even easier conditional addition (or removal) of hooked blocks for a given anchor block and relative position.

function insert_shopping_cart_hooked_block( $hooked_blocks, $position, $anchor_block, $context ) {
        if ( 'after' === $position && 'core/navigation' && $anchor_block && /** $context is header template part **/ ) {
                $hooked_blocks[] = 'mycommerce/shopping-cart';
        }
        return $hooked_blocks;
}
add_filter( 'hooked_block_types', 'insert_shopping_cart_hooked_block', 10, 4 );

Trac ticket: https://core.trac.wordpress.org/ticket/59424

FYI @nerrad @ndiego

[gziolo]

I left my feedback on the PR. I like the proposal very much and I would be in favor of replacing existing low-level filters with hooked_block_types.

Excellent idea with the new better scoped filters hooked_block_types. I would be in favor of removing inject_hooked_block_markup filters as they are low-level and offer too much power in contrast to the new proposal. We can always add them back later if it turns out they are essential for more advanced usage that I can't think of at the moment.

Great, thank you! I agree 100% -- YAGNI and all 😉
I'll land this change, and will then do a follow-up to remove inject_hooked_block_markup.

[Bernhard Reiter]

In 56673:

Blocks: Introduce filter to allow easy addition of hooked blocks.

Introduce a hooked_block_types filter that allows easier conditional addition (or removal) of hooked blocks for a given anchor block and relative position.

function insert_shopping_cart_hooked_block( $hooked_blocks, $position, $anchor_block, $context ) {
        if ( 'after' === $position && 'core/navigation' === $anchor_block && /** $context is header template part **/ ) {
                $hooked_blocks[] = 'mycommerce/shopping-cart';
        }
        return $hooked_blocks;
}
add_filter( 'hooked_block_types', 'insert_shopping_cart_hooked_block', 10, 4 );

Props gziolo, nerrad, dmsnell, ndiego.
Fixes #59424.

Committed to Core in https://core.trac.wordpress.org/changeset/56673.