Initial plugin API

pkg/analysis_server/lib/src/plugin/server_plugin.dart

+// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library analysis_server.src.plugin.plugin_impl;
+
+import 'package:analysis_server/plugin/plugin.dart';
+import 'package:analysis_server/src/analysis_server.dart';
+import 'package:analysis_server/src/domain_server.dart';
+import 'package:analysis_server/src/protocol.dart';
+
+/**
+ * A function that will create a request handler that can be used by the given
+ * [server].
+ *
+ * TODO(brianwilkerson) Move this into 'protocol.dart'.
+ */
+typedef RequestHandler RequestHandlerFactory(AnalysisServer server);
+
+/**
+ * A plugin that defines the extension points and extensions that are inherently
+ * defined by the analysis server.
+ */
+class ServerPlugin implements Plugin {
+  /**
+   * The simple identifier of the extension point that allows plugins to
+   * register new domains with the server.
+   */
+  static const String DOMAIN_EXTENSION_POINT = 'domain';
+
+  /**
+   * The unique identifier of this plugin.
+   */
+  static const String UNIQUE_IDENTIFIER = 'analysis_server.core';
+
+  /**
+   * Initialize a newly created plugin.
+   */
+  ServerPlugin();
+
+  @override
+  String get uniqueIdentifier => UNIQUE_IDENTIFIER;
+
+  @override
+  void registerExtensionPoints(RegisterExtensionPoint registerExtensionPoint) {
+    registerExtensionPoint(
+        DOMAIN_EXTENSION_POINT,
+        (Object extension) => extension is RequestHandlerFactory);
+  }
+
+  @override
+  void registerExtensions(RegisterExtension registerExtension) {
+    String domainId = Plugin.join(UNIQUE_IDENTIFIER, DOMAIN_EXTENSION_POINT);
+    registerExtension(
+        domainId,
+        (AnalysisServer server) => new ServerDomainHandler(server));
+    // TODO(brianwilkerson) Register the other domains.
+  }
+}