Magento 1.9 – How to Debug Class Not Found Autoloader Error

autoloadercomposerevent-observermagento-1magento-1.9

So, I'm facing the almighty "Class Bla not found" error on one of my website.

The class file sits in the vendor folder and I'm using an event observer for the autoload:

<events>
    <resource_get_tablename>
        <observers>
            <composer_autoloader>
                <type>singleton</type>
                <class>module/observer</class>
                <method>addComposerAutoloader</method>
            </composer_autoloader>
        </observers>
    </resource_get_tablename>
</events>

Here's my observer:

class Vendor_Module_Model_Observer
{
    /**
     * @var bool
     */
    protected static $added = false;
    /**
     * Register the Composer autoloader
     * @param Varien_Event_Observer $observer
     */
    public function addComposerAutoloader(Varien_Event_Observer $observer)
    {
        if (self::$added === false) {
            /** @var $helper Vendor_Module_Helper_Data */
            $helper = Mage::helper('module');
            $helper->registerAutoloader();
            self::$added = true;
        }
    }
}

And here's my helper method:

public function registerAutoloader($path = null, $filename = null)
{
    if ($path === null) {
        $path = $this->getVendorDirectoryPath();
    }
    if ($filename === null) {
        $filename = self::AUTOLOAD_FILENAME;
    }
    if (file_exists($path . DS . $filename)) {
        require_once($path . DS . $filename);
    }
}

According to my tests using xDebug, the observer is properly triggered and the require_once leading to my vendor/autoload.php is called.

I've checked the namespace I use to call my custom class and I'm 100% sure there's no typo.

NB: please note that if I get rid of this composer code and if I patch the app/Mage.php directly with the following code, it does not work either:

/** AUTOLOADER PATCH **/
if (file_exists($autoloaderPath = BP . DS . '../vendor/autoload.php') ||
    file_exists($autoloaderPath = BP . DS . 'vendor/autoload.php')
) {
    require $autoloaderPath;
}
/** AUTOLOADER PATCH **/

So my question is: how do I debug that error ? Any usual suspects ?

Best Answer

So my question is: how do I debug that error ? Any usual suspects ?

Breakpoints in lib/Varien/Autoload.php and vendor/autoload.php. Or in a new Here_Your_Class_Name line to see in which order the autoloaders are registered.

That's a typical problem: the Varien Autoloader is called first and it has this bug that it does not verify if the resolved file path can be included (i.e. the file exists), then fails instead of letting other autoloaders try1.

spl_autoload_register() has a prepend parameter, that you must use if you register your autoloader anytime after Varien_Autoload.

But I just checked, the composer autoloader uses $prepend = true, so not a problem in your case.

Another thing that comes to mind: Make sure the composer autoloader is up to date by running composer dump-autoload.

1) can be easily fixed using stream_resolve_include_path()

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