crunchbutton/include/library/QueryPath/ExtensionRegistry.php

131 lines
3.9 KiB
PHP
Executable File

<?php
/**
* @file
* The extension registry.
*/
namespace QueryPath;
/**
* A registry for QueryPath extensions.
*
* QueryPath extensions should call the QueryPath::ExtensionRegistry::extend()
* function to register their extension classes. The QueryPath library then
* uses this information to determine what QueryPath extensions should be loaded and
* executed.
*
* Extensions are attached to a Query object.
*
* To enable an extension (the easy way), use QueryPath::enable().
*
* This class provides lower-level interaction with the extension
* mechanism.
*
* @ingroup querypath_extensions
*/
class ExtensionRegistry {
/**
* Internal flag indicating whether or not the registry should
* be used for automatic extension loading. If this is false, then
* implementations should not automatically load extensions.
*/
public static $useRegistry = TRUE;
/**
* The extension registry. This should consist of an array of class
* names.
*/
protected static $extensionRegistry = array();
protected static $extensionMethodRegistry = array();
/**
* Extend a Query with the given extension class.
*/
public static function extend($classname) {
self::$extensionRegistry[] = $classname;
$class = new \ReflectionClass($classname);
$methods = $class->getMethods();
foreach ($methods as $method) {
self::$extensionMethodRegistry[$method->getName()] = $classname;
}
}
/**
* Check to see if a method is known.
* This checks to see if the given method name belongs to one of the
* registered extensions. If it does, then this will return TRUE.
*
* @param string $name
* The name of the method to search for.
* @return boolean
* TRUE if the method exists, false otherwise.
*/
public static function hasMethod($name) {
return isset(self::$extensionMethodRegistry[$name]);
}
/**
* Check to see if the given extension class is registered.
* Given a class name for a QueryPath::Extension class, this
* will check to see if that class is registered. If so, it will return
* TRUE.
*
* @param string $name
* The name of the class.
* @return boolean
* TRUE if the class is registered, FALSE otherwise.
*/
public static function hasExtension($name) {
return in_array($name, self::$extensionRegistry);
}
/**
* Get the class that a given method belongs to.
* Given a method name, this will check all registered extension classes
* to see if any of them has the named method. If so, this will return
* the classname.
*
* Note that if two extensions are registered that contain the same
* method name, the last one registred will be the only one recognized.
*
* @param string $name
* The name of the method.
* @return string
* The name of the class.
*/
public static function getMethodClass($name) {
return self::$extensionMethodRegistry[$name];
}
/**
* Get extensions for the given Query object.
*
* Given a Query object, this will return
* an associative array of extension names to (new) instances.
* Generally, this is intended to be used internally.
*
* @param Query $qp
* The Query into which the extensions should be registered.
* @return array
* An associative array of classnames to instances.
*/
public static function getExtensions(Query $qp) {
$extInstances = array();
foreach (self::$extensionRegistry as $ext) {
$extInstances[$ext] = new $ext($qp);
}
return $extInstances;
}
public static function extensionNames() {
return self::$extensionRegistry;
}
/**
* Enable or disable automatic extension loading.
*
* If extension autoloading is disabled, then QueryPath will not
* automatically load all registred extensions when a new Query
* object is created using qp().
*/
public static function autoloadExtensions($boolean = TRUE) {
self::$useRegistry = $boolean;
}
}