| // Copyright (c) 2016, 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. |
| |
| import 'dart:convert'; |
| |
| /// A sink that provides access to the concatenated strings passed to it. |
| /// |
| /// See also [StringConversionSink.withCallback]. |
| class StringAccumulatorSink extends StringConversionSinkBase { |
| /// The string accumulated so far. |
| String get string => _buffer.toString(); |
| final _buffer = StringBuffer(); |
| |
| /// Whether [close] has been called. |
| bool get isClosed => _isClosed; |
| var _isClosed = false; |
| |
| /// Empties [string]. |
| /// |
| /// This can be used to avoid double-processing data. |
| void clear() { |
| _buffer.clear(); |
| } |
| |
| void add(String chunk) { |
| if (_isClosed) { |
| throw StateError("Can't add to a closed sink."); |
| } |
| |
| _buffer.write(chunk); |
| } |
| |
| void addSlice(String chunk, int start, int end, bool isLast) { |
| if (_isClosed) { |
| throw StateError("Can't add to a closed sink."); |
| } |
| |
| _buffer.write(chunk.substring(start, end)); |
| if (isLast) _isClosed = true; |
| } |
| |
| void close() { |
| _isClosed = true; |
| } |
| } |