sdk/lib/_internal/compiler/implementation/js_emitter/class_builder.dart

// Copyright (c) 2013, 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.

part of dart2js.js_emitter;

/**
 * A data structure for collecting fragments of a class definition.
 */
class ClassBuilder {
  final List<jsAst.Property> properties = <jsAst.Property>[];
  final List<String> fields = <String>[];

  String superName;
  String functionType;
  List<jsAst.Node> fieldMetadata;

  final Namer namer;

  /// Set to true by user if class is indistinguishable from its superclass.
  bool isTrivial = false;

  ClassBuilder(this.namer);

  // Has the same signature as [DefineStubFunction].
  void addProperty(String name, jsAst.Expression value) {
    properties.add(new jsAst.Property(js.string(name), value));
  }

  void addField(String field) {
    fields.add(field);
  }

  jsAst.ObjectInitializer toObjectInitializer() {
    StringBuffer buffer = new StringBuffer();
    if (superName != null) {
      buffer.write('$superName');
      if (functionType != null) {
        buffer.write(':$functionType');
      }
      buffer.write(';');
    }
    buffer.writeAll(fields, ',');
    var classData = js.string('$buffer');
    if (fieldMetadata != null) {
      // If we need to store fieldMetadata, classData is turned into an array,
      // and the field metadata is appended. So if classData is just a string,
      // there is no field metadata.
      classData =
          new jsAst.ArrayInitializer.from([classData]..addAll(fieldMetadata));
    }
    var fieldsAndProperties =
        [new jsAst.Property(js.string(namer.classDescriptorProperty),
                            classData)]
        ..addAll(properties);
    return new jsAst.ObjectInitializer(fieldsAndProperties, isOneLiner: false);
  }

}