path-mapping.md

Path mapping

Directories and files must either be namespace-mapped or web-mapped

The pathnames throughout a project must be obvious by either mapping directly to a class's namespace, or relate to a requested URL.

Namespace-mapping example

Assuming a project's root directory is at /app, and the namespace root for MyApp is set to ./src/class:

/app/src/class/User/Settings.php:

<?php
namepsace MyApp\User;

class Settings {
// ...
}

Web-mapping example

If a PHP class acts as a controller for page logic its pathname must correspond to the requested URL it serves. Hyphens in URLs are kept in filenames, but are dropped in class names, upper-casing the words instead.

A consistent set of rules must be used. Assuming a project's root directory is at /app, the base page directory is set to ./src/page, and the class suffix for pages is Page:

URL requested http://example.com/user/advanced-settings

/app/src/page/user/advanced-settings.php:

<?php
namespace MyApp\Page\User;

class AdvancedSettingsPage {
// ...
}

URL requested: http://example.com/post-list

/app/src/page/post-list.php:

<?php
namespace MyApp\Page;

class PostListPage {
// ...
}

Namespaces must map to file paths, as per PSR-4

When using namespace-mapped classes, a PHP file's pathname must correspond to its fully qualified class name with respect to PSR-4 namespace root(s) defined in the project.

composer.json

{
	"autoload": {
		"psr-4": {
			"MyApp\\": "src/class"
		}
	}
}

/app/src/class/Model/User.php:

<?php
namespace MyApp\Model;

class User {
// ...
}