libwebserv/response.h

// Copyright 2015 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef WEBSERVER_LIBWEBSERV_RESPONSE_H_
#define WEBSERVER_LIBWEBSERV_RESPONSE_H_

#include <map>
#include <memory>
#include <string>
#include <utility>
#include <vector>

#include <base/macros.h>
#include <chromeos/streams/stream.h>
#include <libwebserv/export.h>

namespace base {
class Value;
}  // namespace base

namespace libwebserv {

class ProtocolHandler;

// Response class is a proxy for HTTP response used by the request handler
// to provide response HTTP headers and data.
class LIBWEBSERV_EXPORT Response final {
 public:
  ~Response();

  // Adds a single HTTP response header to the response.
  void AddHeader(const std::string& header_name, const std::string& value);

  // Adds number of HTTP response headers to the response.
  void AddHeaders(
      const std::vector<std::pair<std::string, std::string>>& headers);

  // Generic reply method for sending arbitrary binary data response.
  void Reply(int status_code,
             chromeos::StreamPtr data_stream,
             const std::string& mime_type);

  // Reply with text body.
  void ReplyWithText(int status_code,
                     const std::string& text,
                     const std::string& mime_type);

  // Reply with JSON object. The content type will be "application/json".
  void ReplyWithJson(int status_code, const base::Value* json);

  // Special form for JSON response for simple objects that have a flat
  // list of key-value pairs of string type.
  void ReplyWithJson(int status_code,
                     const std::map<std::string, std::string>& json);

  // Issue a redirect response, so the client browser loads a page at
  // the URL specified in |redirect_url|. If this is not an external URL,
  // it must be an absolute path starting at the root "/...".
  void Redirect(int status_code, const std::string& redirect_url);

  // Send a plain text response (with no Content-Type header).
  // Usually used with error responses. |error_text| must be plain text.
  void ReplyWithError(int status_code, const std::string& error_text);

  // Send "404 Not Found" response.
  void ReplyWithErrorNotFound();

 private:
  friend class ProtocolHandler;

  LIBWEBSERV_PRIVATE Response(ProtocolHandler* handler,
                              const std::string& request_id);

  LIBWEBSERV_PRIVATE void SendResponse();

  ProtocolHandler* handler_{nullptr};
  std::string request_id_;
  int status_code_{0};
  chromeos::StreamPtr data_stream_;
  std::multimap<std::string, std::string> headers_;
  bool reply_sent_{false};

  DISALLOW_COPY_AND_ASSIGN(Response);
};

}  // namespace libwebserv

#endif  // WEBSERVER_LIBWEBSERV_RESPONSE_H_