While any valid PHP callback may be registered with spl_autoload_register(), Zend Framework autoloaders often provide more flexibility by being stateful and allowing configuration. To provide a common interface, Zend Framework provides the SplAutoloader interface. Objects implementing this interface provide a standard mechanism for configuration, a method that may be invoked to attempt to load a class, and a method for registering with the SPL autoloading mechanism. To create your own autoloading mechanism, simply create a class implementing the SplAutoloader interface (you may review the methods defined in the Methods section). As a simple example, consider the following autoloader, which will look for a class file named after the class within a list of registered directories. setOptions($options); } } public function setOptions($options) { if (!is_array($options) && !($options instanceof Traversable)) { throw new InvalidArgumentException(); } foreach ($options as $path) { if (!in_array($path, $this->paths)) { $this->paths[] = $path; } } return $this; } public function autoload($classname) { $filename = $classname . '.php'; foreach ($this->paths as $path) { $test = $path . DIRECTORY_SEPARATOR . $filename; if (file_exists($test)) { return include($test); } } return false; } public function register() { spl_autoload_register(array($this, 'autoload')); } } ]]> This component defines no configuration options, as it is an interface. __construct $options = null Initialize and configure an autoloader Autoloader constructors should optionally receive configuration options. Typically, if received, these will be passed to the setOptions() method to process. setOptions $options Configure the autoloader state Used to configure the autoloader. Typically, it should expect either an array or a Traversable object, though validation of the options is left to implementation. Additionally, it is recommended that the method return the autoloader instance in order to implement a fluent interface. autoload $classname Attempt to resolve a class name to the file defining it This method should be used to resolve a class name to the file defining it. When a positive match is found, return the class name; otherwise, return a boolean false. register Register the autoloader with the SPL autoloader Should be used to register the autoloader instance with spl_autoload_register(). Invariably, the method should look like the following: Please see the Quick Start for a complete example.