Add an is_dir check to prevent a notice from a missing directory with RecursiveDirectoryIterator

[srtfisher]

Though https://core.trac.wordpress.org/ticket/58196 improved the performance of _get_block_templates_paths() in 77dcb17, this does throw a notice:

RecursiveDirectoryIterator::__construct(/var/www/wp-content/themes/:theme/templates): Failed to open directory: No such file or directory

Trac ticket: https://core.trac.wordpress.org/ticket/60915

---

This Pull Request is for code review only. Please keep all other discussion in the Trac ticket. Do not merge this Pull Request. See GitHub Pull Requests for Code Review in the Core Handbook for more details.

[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

Core Committers: Use this line as a base for the props when committing in SVN:

Props sean212, joemcgill.

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

[github-actions]

Test using WordPress Playground

The changes in this pull request can previewed and tested using a WordPress Playground instance.

WordPress Playground is an experimental project that creates a full WordPress instance entirely within the browser.

Some things to be aware of

• The Plugin and Theme Directories cannot be accessed within Playground.
• All changes will be lost when closing a tab with a Playground instance.
• All changes will be lost when refreshing the page.
• A fresh instance is created each time the link below is clicked.
• Every time this pull request is updated, a new ZIP file containing all changes is created. If changes are not reflected in the Playground instance,
  it's possible that the most recent build failed, or has not completed. Check the list of workflow runs to be sure.

For more details about these limitations and more, check out the Limitations page in the WordPress Playground documentation.

Test this pull request with WordPress Playground.

[joemcgill]

Thanks, @srtfisher!

In https://core.trac.wordpress.org/changeset/57215, the main performance benefit was memoizing the template path list. Introducing the try/catch block was a micro-optimization to avoid the need for a file_exists check. It's odd that New Relic seems to be reporting these caught exceptions anyway. I suspect that this is a NR bug, but I can see how it would be disruptive.

I think we could just remove the try/catch block altogether and do something like this:

function _get_block_templates_paths( $base_directory ) {
	static $template_path_list = array();
	if ( isset( $template_path_list[ $base_directory ] ) ) {
		return $template_path_list[ $base_directory ];
	}

	$path_list = array();
	if ( is_dir( $base_directory ) ) {
		$nested_files      = new RecursiveIteratorIterator( new RecursiveDirectoryIterator( $base_directory ) );
		$nested_html_files = new RegexIterator( $nested_files, '/^.+\.html$/i', RecursiveRegexIterator::GET_MATCH );
		foreach ( $nested_html_files as $path => $file ) {
			$path_list[] = $path;
		}
	}
	$template_path_list[ $base_directory ] = $path_list;

	return $path_list;
}

[srtfisher]

@joemcgill thank you! I applied your feedback.

[joemcgill]

Thanks @srtfisher. I'm going to do a bit of testing, but I think this looks good.

[mukeshpanchal27]

Instead of checking here could we add condition at top?

if ( ! is_dir( $base_directory ) ) {

[joemcgill]

I think we still want to memoize the path list even when there is no directory, otherwise the is_dir() check would get repeated unnecessarily, so keeping it as is should be fine.

[mukeshpanchal27]

Committed https://core.trac.wordpress.org/changeset/57947