How to create a page template from a plugin so that a selection appears in the page attributes

Additional to the third method for the article 3 ways to create a page template

1 Option: with a single template

add_filter( 'theme_page_templates', 'my_plugin_template' );
add_filter( 'template_include', 'my_plugin_template_to_page' );

function my_plugin_template( $templates ) {

	// template selection in page attributes
	$templates['full-page.php'] = 'Full Page';

	return $templates;
}

function my_plugin_template_to_page( $template ) {

	// request the active template of the current page
	$page_template = get_page_template_slug();

	// compare the active template and the template selected in the attributes
	if ( 'full-page.php' == basename( $page_template ) ) {

		// include the template if 'Full Page' is selected
		return wp_normalize_path( WP_PLUGIN_DIR . '/mland/templates/full-page.php' );

	}

	return $template;
}

2 Option: with multiple templates in one plugin folder

The template name in the attributes automatically becomes in the format: My Template.

add_filter( 'theme_page_templates', 'my_plugin_template' );
add_filter( 'template_include', 'my_plugin_template_to_page' );

## select templates from the plugin in page attributes
function my_plugin_template( $templates ) {

	## scan the template folder in the plugin
	// define( 'ML_TEMPLATES_DIR', WP_PLUGIN_DIR . '/my-plugin/templates' );
	$array_templates = array_diff( scandir( ML_TEMPLATES_DIR ), array('.', '..') );

	foreach( $array_templates as $plugin_template ) {

		$str_template = str_replace( ".php", "", $plugin_template ); // clear of .php

		$str_template = str_replace( "-", " ", $str_template ); // clear of "-"

		// Output the name in the format: My Template
		$template_name = mb_convert_case( $str_template, MB_CASE_TITLE, 'UTF-8' );

		// Connect the template selection in the attributes
		$templates[ $plugin_template ] = $template_name;

	}

	return $templates;

}

## connecting templates from the plugin
function my_plugin_template_to_page( $template ) {

	// request the active template of the current page
	$page_template = get_page_template_slug();

	## connecting templates
	// scan the template folder
	$mland_templates = array_diff( scandir( ML_TEMPLATES_DIR ), array('.', '..') );

	foreach( $mland_templates as $mland_template ) {

		// compare the active template and the template selected in the attributes
		if ( $mland_template == basename ( $page_template ) ) {

			// connect the template
			return wp_normalize_path( ML_TEMPLATES_DIR . '/' . $mland_template );

		}

	}

	return $template;
}

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