Update defaults for Home Link block

[tjcafferkey]

Description

It's now possible to use the Block Hooks API to insert inner blocks into the core Navigation block #57754. Using this API currently doesn't allow you to set attributes along with the hooked block.

We found that when you use the API to insert the core/home-link block it has insufficient default attributes. When we insert this block via the API we can't set any attributes and one of the conditions for this block to render server-side is a label attribute, see here.

When you insert the block via the editor, this gets added on the client-side. See here.

Step-by-step reproduction instructions

1. Add the below code to your site.
2. Load frontend and see that the block doesn't render at all.
3. Change core/home-link to core/loginout in the snippet below to see a block rendering correctly as comparison.

function register_home_link_block_as_navigation_last_child( $hooked_blocks, $position, $anchor_block, $context ) {
	if ( $anchor_block === 'core/navigation' && $position === 'last_child' ) {
		$hooked_blocks[] = 'core/home-link';
	}

	return $hooked_blocks;
}

add_filter( 'hooked_block_types', 'register_home_link_block_as_navigation_last_child', 10, 4 );

Screenshots, screen recording, code snippet

No response

Environment info

• WP 6.4
• Gutenberg latest trunk or 17.6 and above.

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes

[ockham]

When you insert the block via the editor, this gets added on the client-side. See here.

I was wondering why this wasn't done via an attribute default when the block was created in the first place. Maybe it's the i18n? I.e. the __( 'Home' ) bit?

gutenberg/packages/block-library/src/home-link/edit.js

Line 52 in 9363cf0

setAttributes( { label: __( 'Home' ) } );

(I'm not sure if we have a mechanism to support localized strings like that in block.json nowadays 🤔 )

[ockham]

Looks like this is the authoritative source of what block.json fields are translated (h/t @MaggieCabrera for the pointer!)

No attribute defaults in that one. So that might explain why this was done on the editor side in the first place 😬

[tjcafferkey]

Thanks @ockham! I suspected it may have something to do with translations. Maybe instead of setting the attribute if there isn't one, we can render __( 'Home' ) in the absence of this attribute but allow users to override it by explicitly setting it still?

[ockham]

Thanks @ockham! I suspected it may have something to do with translations. Maybe instead of setting the attribute if there isn't one, we can render __( 'Home' ) in the absence of this attribute but allow users to override it by explicitly setting it still?

That sounds like a good idea! It would basically reflect the behavior in the editor, and allow inclusion of a Home Link block with no attributes set 👍

[ockham]

Looks like this is the authoritative source of what block.json fields are translated (h/t @MaggieCabrera for the pointer!)

No attribute defaults in that one. So that might explain why this was done on the editor side in the first place 😬

Post-scriptum, looks like it was actually discussed at the time: https://github.com/WordPress/gutenberg/pull/30293/files#r619407489