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//* =================================================
//* Mostly from Mor10's Lynda course
//* Add various fields to the WP REST API JSON output
//* https://www.lynda.com/WordPress-tutorials/WordPress-REST-API-WP-API-First-Look/383783-2.html

function register_new_restapi_fields() {
	// Add Author Name
	register_api_field( 'post',
		'author_name',
		array(
			'get_callback'    => 'get_author_name_from_restapi',
			'update_callback' => null,
			'schema'          => null
		)
	);

	register_api_field( 'post',
		'category_name',
		array(
			'get_callback'    => 'get_category_name_from_restapi',
			'update_callback' => null,
			'schema'          => null
		)
	);

	// Add Featured Image
	register_api_field( 'post',
		'featured_image_src',
		array(
			'get_callback'    => 'get_image_src_from_restapi',
			'update_callback' => null,
			'schema'          => null
		)
	);
}

function get_author_name_from_restapi( $object, $field_name, $request ) {
	return get_the_author_meta( 'display_name' );
}

function get_category_name_from_restapi( $object, $field_name, $request ) {
	$cats = [];
	foreach ($object['categories'] as $cat ) {
		array_push($cats, get_cat_name($cat));
	}
	return $cats;
}

function get_image_src_from_restapi( $object, $field_name, $request ) {
	$imgArray = wp_get_attachment_image_src( get_post_thumbnail_id( $object['id'] ), 'full' );

	return $imgArray[0];
}

add_action( 'rest_api_init', __NAMESPACE__ . '\register_new_restapi_fields' );
//* end Mor10's code
//* =================================================