1 files changed, 130 insertions, 0 deletions
diff --git a/lib/querypath/src/QueryPath/ExtensionRegistry.php b/lib/querypath/src/QueryPath/ExtensionRegistry.php
new file mode 100644
index 0000000..963edd3
--- /dev/null
+++ b/lib/querypath/src/QueryPath/ExtensionRegistry.php
@@ -0,0 +1,130 @@
+<?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;
+  }
+}