Support for parsing HTML in the new task model

pkg/analyzer/lib/src/task/html.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 analyzer.src.task.html;
+
+import 'package:analyzer/src/generated/engine.dart' hide AnalysisTask;
+import 'package:analyzer/src/generated/source.dart';
+import 'package:analyzer/src/task/general.dart';
+import 'package:analyzer/task/general.dart';
+import 'package:analyzer/task/html.dart';
+import 'package:analyzer/task/model.dart';
+import 'package:html/dom.dart';
+import 'package:html/parser.dart';
+
+/**
+ * A task that scans the content of a file, producing a set of Dart tokens.
+ */
+class ParseHtmlTask extends SourceBasedAnalysisTask {
+  /**
+   * The name of the input whose value is the content of the file.
+   */
+  static const String CONTENT_INPUT_NAME = 'CONTENT_INPUT_NAME';
+
+  /**
+   * The task descriptor describing this kind of task.
+   */
+  static final TaskDescriptor DESCRIPTOR = new TaskDescriptor('ParseHtmlTask',
+      createTask, buildInputs, <ResultDescriptor>[DOCUMENT, DOCUMENT_ERRORS]);
+
+  /**
+   * Initialize a newly created task to access the content of the source
+   * associated with the given [target] in the given [context].
+   */
+  ParseHtmlTask(InternalAnalysisContext context, AnalysisTarget target)
+      : super(context, target);
+
+  @override
+  TaskDescriptor get descriptor => DESCRIPTOR;
+
+  @override
+  void internalPerform() {
+    String content = getRequiredInput(CONTENT_INPUT_NAME);
+
+    HtmlParser parser = new HtmlParser(content);
+    Document document = parser.parse();
+    List<ParseError> errors = parser.errors;
+
+    outputs[DOCUMENT] = document;
+    outputs[DOCUMENT_ERRORS] = errors;
+  }
+
+  /**
+   * Return a map from the names of the inputs of this kind of task to the task
+   * input descriptors describing those inputs for a task with the given
+   * [source].
+   */
+  static Map<String, TaskInput> buildInputs(Source source) {
+    return <String, TaskInput>{CONTENT_INPUT_NAME: CONTENT.of(source)};
+  }
+
+  /**
+   * Create a [ParseHtmlTask] based on the given [target] in the given [context].
+   */
+  static ParseHtmlTask createTask(
+      AnalysisContext context, AnalysisTarget target) {
+    return new ParseHtmlTask(context, target);
+  }
+}