Basic plugin config parsing.

pkg/analyzer/lib/src/plugin/plugin_configuration.dart

Index: pkg/analyzer/lib/src/plugin/plugin_configuration.dart
diff --git a/pkg/analyzer/lib/src/plugin/plugin_configuration.dart b/pkg/analyzer/lib/src/plugin/plugin_configuration.dart
new file mode 100644
index 0000000000000000000000000000000000000000..b3a1d9061e8b53f6cfc6b8b2ec4d8e17b866978d
--- /dev/null
+++ b/pkg/analyzer/lib/src/plugin/plugin_configuration.dart
@@ -0,0 +1,119 @@
+// 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 analyzer.src.plugin.plugin_configuration;
+
+import 'package:analyzer/plugin/options.dart';
+import 'package:yaml/yaml.dart';
+
+const _analyzerOptionScope = 'analyzer';
+
+const _pluginOptionScope = 'plugins';
+
+PluginInfo _processPluginMapping(dynamic name, dynamic details) {
+  if (name is String) {
+    if (details is String) {
+      return new PluginInfo(name: name, version: details);
+    }
+    if (details is YamlMap) {
+      return new PluginInfo(
+          name: name,
+          version: details['version'],
+          className: details['class_name'],
+          libraryUri: details['library_uri'],
+          packageName: details['package_name'],
+          path: details['path']);
+    }
+  }
+
+  return null;
+}
+
+PluginInfo _processPluginNode(dynamic node) {
+  if (node is String) {
+    return new PluginInfo(name: node);
+  }
+  if (node is YamlMap) {
+    if (node.length == 1) {
+      return new PluginInfo(name: node.keys.first, version: node.values.first);
+    }
+  }
+  return null;
+}
+
+typedef ErrorHandler(Exception);
+
+/// Describes plugin configuration information as extracted from an
+/// analysis options map.
+class PluginConfig {
+  final Iterable<PluginInfo> plugins;
+  PluginConfig(this.plugins);
+
+  /// Create a plugin configuration from an options map.
+  factory PluginConfig.fromOptions(Map<String, YamlNode> options) {
+    List<PluginInfo> plugins = [];
+    var analyzerOptions = options[_analyzerOptionScope];
+    if (analyzerOptions != null) {
+      if (analyzerOptions is YamlMap) {
+        var pluginConfig = analyzerOptions[_pluginOptionScope];
+        if (pluginConfig is YamlMap) {
+          pluginConfig.forEach((name, details) {
+            var plugin = _processPluginMapping(name, details);
+            if (plugin != null) {
+              plugins.add(plugin);
+            }
+          });
+        } else {
+          var plugin = _processPluginNode(pluginConfig);
+          if (plugin != null) {
+            plugins.add(plugin);
+          }
+        }
+      }
+    }
+
+    return new PluginConfig(plugins);
+  }
+}
+
+/// Extracts plugin config details from analysis options.
+class PluginConfigOptionsProcessor extends OptionsProcessor {
+  final ErrorHandler _errorHandler;
+
+  PluginConfig _config;
+
+  PluginConfigOptionsProcessor([this._errorHandler]);
+
+  /// The processed plugin config.
+  PluginConfig get config => _config;
+
+  @override
+  void onError(Exception exception) {
+    if (_errorHandler != null) {
+      _errorHandler(exception);
+    }
+  }
+
+  @override
+  void optionsProcessed(Map<String, YamlNode> options) {
+    _config = new PluginConfig.fromOptions(options);
+  }
+}
+
+/// Describes plugin information.
+class PluginInfo {
+  final String name;
+  final String className;
+  final String version;
+  final String libraryUri;
+  final String packageName;
+  final String path;
+  PluginInfo(
+      {this.name,
+      this.version,
+      this.className,
+      this.libraryUri,
+      this.packageName,
+      this.path});
+}