How Zend_Loader_Autoloader works_PHP tutorial

The principle of automatic loading is that Zend_Application instantiates Zend_Loader_Autoloader, causing it to call spl_autoload_register(array(__CLASS__, 'autoload')); In this way, if the class cannot be found, the autoload method of this object will be called for processing.

A namespace can have multiple loaders. After iterating to find the matching custom loader, the rest will not be used. Generally, we will only register a custom loader for a namespace or directly use the default one. loader.

There are two ways to register a namespace:

• Only the prefix of the space is registered, no loader is specified, and the registration method is registerNamespace('space name').
• The space prefix is ​​registered and the loader is specified. The registration method is pushAutoloader(loader, 'space name') or unshiftAutoloader(loader, 'space name'). The difference between the two methods is that push puts the loader after the loader queue with the specified space name, and unshift is before it.

When a class is not found and required to be loaded, its class name is handed over to Zend_Loader_Autoloader::autoload(), which will go through the following processes:

• Compare the registered namespace prefix with this type of name to find the loader specified by the namespace.

1. Compare the second name prefix of the namespace registration method with the prefix of this type of name to find the loader specified by the namespace.
2. Compare the first name prefix in the namespace registration method with the name prefix of this type. If it exists, use the Zend loader.
3. If there is no namespace prefix equal to this class, and the FallbackAutoloader flag is set, Zend's loader will also be used, otherwise no loader will be returned, and this class cannot be loaded.

If the loader is a class that implements the Zend_Loader_Autoloader_Interface interface, pass the class name to its autoload method to load. If the loader is a function, use the class name as a parameter of this function to load. If the loader is an array, use the call_user_func callback function to load it.

Customized loaders come in the following forms:

1. An object that implements the Zend_Loader_Autoloader_Interface interface

$autoloader = Zend_Loader_Autoloader::getInstance();
$myAutoloaderClass = new my_Autoloader();
$autoloader->pushAutoloader($myAutoloaderClass, myNamespace);

2. A function

$autoloader = Zend_Loader_Autoloader::getInstance();
function myAutoloaderFun(){ //TODO };
$autoloader->pushAutoloader('myAutoloaderFun', myNamespace);

3. Call a method of an object or class in callback mode. (Return function call_user_func)

$autoloader = Zend_Loader_Autoloader::getInstance();
$autoloader->pushAutoloader(array('类名', '方法'), myNamespace);

The Zend loader object method is Zend_Loader_Autoloader::_autoload. This method will use call_user_func to call the final loading method such as array('Zend_Loader', 'loadClass') by default to load the current object.

http://www.bkjia.com/PHPjc/752435.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/752435.htmlTechArticleThe principle of automatic loading is that Zend_Application instantiates Zend_Loader_Autoloader, causing it to call spl_autoload_register(array(__CLASS__, 'autoload') ); This way if the class cannot be found, this will be called...