Magento 2: Stable way to Get a the Base Directory of a Module

Question

In Magento 1, the static getModuleDir method of the Mage class

Mage::getModuleDir('', 'Mage_Core') 

provided a stable, "works across versions" way of getting the base folder of a Magento module.

Does Magento 2 have something similar? I found the Magento\Framework\Module\Dir\Reader class that has a getModuleDir method.

#File: vendor/magento/framework/Module/Dir/Reader.php
/**
 * Get module directory by directory type
 *
 * @param string $type
 * @param string $moduleName
 * @return string
 */
public function getModuleDir($type, $moduleName)
{
    if (isset($this->customModuleDirs[$moduleName][$type])) {
        return $this->customModuleDirs[$moduleName][$type];
    }
    return $this->moduleDirs->getDir($moduleName, $type);
}

I could inject this class as a dependency in my own class and call this method. However, this method is not marked with any sort of @api flag, which means it might change unexpectedly.

Is there a safe/stable way for extension developers to determine which folder their module is in (in order to load extra configuration or data files that ship with the module)? Or do we need to roll the dice the the above class, and/or do directory traversing tricks with __FILE__ and __DIR__?

Answer 1

You can use the ComponentRegistrar by injecting ComponentRegistrarInterface and get a module's directory like this:

$path = $this->componentRegistrar->getPath(ComponentRegistrar::MODULE, 'Your_Module');

Since all modules are required to register their directory with this class in their registration.php file, it doesn't seem like something magento would change.