Add: Template and template_lock to post types endpoint.

[jorgefilipecosta]

Backports WordPress/gutenberg#62488 into the core.
Adds template and template_lock property of the post type to post types REST API endpoint.

This change allows us to fix a bug where the template of a page is not respected when creating a new page on the site editor.

Trac ticket:https://core.trac.wordpress.org/ticket/61477

Testing

With the Gutenberg plugin disabled.
I added the following test code to a PHP file:

function myplugin_register_template() {
    $post_type_object = get_post_type_object( 'page' );
    $post_type_object->template = array(
        array( 'core/image' ),
    );
	$post_type_object->template_lock = 'all';
}
add_action( 'init', 'myplugin_register_template' );

I opened the site editor and pasted:
wp.data.select('core').getPostType( 'page' );

I verified the template and template_lock information was included.
I repeated the test with the Gutenberg plugin enabled to make sure things worked well together.

[github-actions]

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Props jorgefilipecosta, oandregal, timothyblynjacobs, mukesh27.

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[github-actions]

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[TimothyBJacobs]

We don't typically completely omit properties if they don't have a value defined. If these don't have a natural default, we should set them to null and add null as an allowed type. See the icon property for an example.

This also needs tests.

[jorgefilipecosta]

We don't typically completely omit properties if they don't have a value defined. If these don't have a natural default, we should set them to null and add null as an allowed type. See the icon property for an example.

This also needs tests.

Hi @TimothyBJacobs, thank you for the review 😊

In the case of template_lock which is an enum with the following possible values array( 'all', 'insert', 'contentOnly' ) would it still be ok to return null when a template_lock does not exist?

[TimothyBJacobs]

Yep! We just need to make sure to add it to the enum list as well.

[oandregal]

We don't typically completely omit properties if they don't have a value defined. If these don't have a natural default, we should set them to null and add null as an allowed type. See the icon property for an example.

I quickly checked for this in my review, thinking specifically about the enum. I approved based on that we actually do this in some places: for example, see the source field, which is an enum and is omitted. I'm happy to go either way, but I want to make sure I understand the rationale/preference.

[TimothyBJacobs]

Gotcha, yeah I don't think we should be doing that there either really. I think for the most part we should be trying to keep the actual properties still defined.

[TimothyBJacobs]

Is an empty array a valid template? Just want to make sure it's not, otherwise the current code will convert it to null. If it is, we can use isset instead.

[jorgefilipecosta]

Is an empty array a valid template? Just want to make sure it's not, otherwise the current code will convert it to null. If it is, we can use isset instead.

Hi @TimothyBJacobs, very good point, an empty template is probably not expected but someone may be doing that I replaced the condition with isset.

[mukeshpanchal27]

Suggested change

	$data['template'] = ! isset( $post_type->template ) ? null : $post_type->template;
	$data['template'] = $post_type->template ) ?? null;

Can we use here ??

[jorgefilipecosta]

Yes, I followed this logic 👍

[jorgefilipecosta]

Is an empty array a valid template? Just want to make sure it's not, otherwise the current code will convert it to null. If it is, we can use isset instead.

Hi @TimothyBJacobs, very good point, an empty template is probably not expected but someone may be doing that I replaced the condition with isset.

It seems like an empty array is even the default: https://github.com/jorgefilipecosta/wordpress-develop/blob/f11d95acf7e65c86733db21975a652820d4dd1fd/src/wp-includes/class-wp-post-type.php#L548-L549

I'm not too fond of these defaults, but they are already like that for a long time so I updated the API to match them.

[mukeshpanchal27]

@ticket annotation is missing.

[jorgefilipecosta]

Committed at 5d41bda.