lib/src/command_processor.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.

part of webdriver;

final ContentType _contentTypeJson =
    new ContentType("application", "json", charset: "utf-8");

class _CommandProcessor {
  final HttpClient client = new HttpClient();

  Lock _lock = new Lock();

  Future<Object> post(Uri uri, dynamic params, {bool value: true}) async {
    await _lock.acquire();
    HttpClientRequest request = await client.postUrl(uri);
    _setUpRequest(request);
    request.headers.contentType = _contentTypeJson;
    if (params != null) {
      var body = UTF8.encode(JSON.encode(params));
      request.contentLength = body.length;
      request.add(body);
    } else {
      request.contentLength = 0;
    }
    return await _processResponse(await request.close(), value);
  }

  Future<Object> get(Uri uri, {bool value: true}) async {
    await _lock.acquire();
    HttpClientRequest request = await client.getUrl(uri);
    _setUpRequest(request);
    return await _processResponse(await request.close(), value);
  }

  Future<Object> delete(Uri uri, {bool value: true}) async {
    await _lock.acquire();
    HttpClientRequest request = await client.deleteUrl(uri);
    _setUpRequest(request);
    return await _processResponse(await request.close(), value);
  }

  _processResponse(HttpClientResponse response, bool value) async {
    var respBody = await UTF8.decodeStream(response);
    _lock.release();
    try {
      respBody = JSON.decode(respBody);
    } catch (e) {}

    if (response.statusCode < 200 ||
        response.statusCode > 299 ||
        (respBody is Map && respBody['status'] != 0)) {
      throw new WebDriverException(
          httpStatusCode: response.statusCode,
          httpReasonPhrase: response.reasonPhrase,
          jsonResp: respBody);
    }
    if (value && respBody is Map) {
      return respBody['value'];
    }
    return respBody;
  }

  void _setUpRequest(HttpClientRequest request) {
    request.followRedirects = false;
    request.headers.add(HttpHeaders.ACCEPT, "application/json");
    request.headers.add(HttpHeaders.ACCEPT_CHARSET, UTF8.name);
    request.headers.add(HttpHeaders.CACHE_CONTROL, "no-cache");
  }
}