Testing: render_block_context POC

[mukeshpanchal27]

Testing PR. DO NOT REVIEW.

---

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[github-actions]

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[mukeshpanchal27]

The POC code used from #7344 (comment)

If we refactor core code per POC the ancestors context will be available in available_context protected key.

For Column block i add two context. 1) how much column wpp-columns 2) column width wpp-col-width

[available_context:protected] => Array
        (
            [postId] => 6
            [postType] => page
            [wpp-columns] => 1
            [wpp-col-width] => 50%
        )

If we use get_block_type_uses_context filter then we get those context in $block->context public array key.

/*
 * Inspiration taken from current block binding implementation.
 * https://github.com/WordPress/wordpress-develop/blob/6.6/src/wp-includes/class-wp-block-bindings-registry.php#L193-L204
 */
add_filter(
	'get_block_type_uses_context',
	function ( $uses_context, $block_type ) {
		if ( 'core/image' === $block_type->name ) {
			// Use array_values to reset the array keys.
			return array_values( array_unique( array_merge( $uses_context, array( 'wpp-columns','wpp-col-width' ) ) ) );
		}
		return $uses_context;
	},
	10,
	2
);

[context] => Array
        (
            [postId] => 6
            [postType] => page
            [wpp-columns] => 1
            [wpp-col-width] => 50%
        )

[felixarntz]

@mukeshpanchal27 A few questions on this. Most importantly, I don't understand how the parent block is set. Not related to this PR, even just generally in Core today.

[felixarntz]

Question: How is $parent_block ever set here? Looking at the full function, it seems that it is only set to null at the top of the function, but then never changed. Will this always be null? 🤔

[mukeshpanchal27]

It was introduce in https://core.trac.wordpress.org/changeset/51894 with message.

Introdices another param to these filters: $parent_block that is the "parent" WP_Block instance for nested blocks and null for top level blocks. Adds unit tests for the filters.

[felixarntz]

Yes, but my question was how does this actually work? As far as I can tell $parent_block is always null. Does it ever get populated with an actual WP_Block instance anywhere?

[mukeshpanchal27]

I don't think. It always null for parent block.

[felixarntz]

But then is that a bug? How does the parent block ever get set for any block?

[felixarntz]

Is this right? Shouldn't the parent block of the inner blocks of this block be $this? Passing $parent_block here I think would effectively pass the "grandparent block".

[mukeshpanchal27]

No effect if i pass $this

[felixarntz]

Can you please clarify what you mean? How do you mean there's no effect?

Logically, the child blocks should access their parent block. But by passing the parent block of the current block here to its child block(s), you're effectively passing the grandparent block, which seems wrong.

[felixarntz]

I know this is a POC, but just noting that if we proceed with implementing this, this will need the original filter comment doc to be added.

[mukeshpanchal27]

Closing in favour of #7522