server::handlers::CustomHandlerException Class Reference

Table of Contents

• Public Types
• Public Member Functions
• Detailed Description
• Member Typedef Documentation
• ExternalBody
• ExtraHeaders
• HandlerErrorCode
• InternalMessage
• ServiceErrorCode
• Constructor & Destructor Documentation
• CustomHandlerException() [1/4]
• Allowed arguments
• Message builders
• CustomHandlerException() [2/4]
• CustomHandlerException() [3/4]
• CustomHandlerException() [4/4]
• Member Function Documentation
• GetCode()
• GetDetails()
• GetExternalErrorBody()
• GetExtraHeaders()
• GetServiceCode()
• IsExternalErrorBodyFormatted()

The generic base class for handler exceptions. Thrown exceptions should typically derive from ExceptionWithCode instead. More...

#include <userver/server/handlers/exceptions.hpp>

Inheritance diagram for server::handlers::CustomHandlerException:

Collaboration diagram for server::handlers::CustomHandlerException:

Public Types
using	HandlerErrorCode = handlers::HandlerErrorCode
using	ServiceErrorCode = handlers::ServiceErrorCode
using	InternalMessage = handlers::InternalMessage
using	ExternalBody = handlers::ExternalBody
using	ExtraHeaders = handlers::ExtraHeaders

Public Member Functions
template<typename... Args>
	CustomHandlerException (HandlerErrorCode handler_code, Args &&... args)
	Construct manually from a set of (mostly optional) arguments, which describe the error details.
	CustomHandlerException (HandlerErrorCode handler_code)
	This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
	CustomHandlerException (ServiceErrorCode service_code, ExternalBody external_body, InternalMessage internal_message, HandlerErrorCode handler_code, ExtraHeaders headers={}, formats::json::Value details={})
template<typename MessageBuilder , typename = std::enable_if_t<impl::kIsMessageBuilder<MessageBuilder>>>
	CustomHandlerException (MessageBuilder &&builder, HandlerErrorCode handler_code)
HandlerErrorCode	GetCode () const
const std::string &	GetServiceCode () const
bool	IsExternalErrorBodyFormatted () const
const std::string &	GetExternalErrorBody () const
const formats::json::Value &	GetDetails () const
const Headers &	GetExtraHeaders () const

Detailed Description

The generic base class for handler exceptions. Thrown exceptions should typically derive from ExceptionWithCode instead.

Definition at line 210 of file exceptions.hpp.

Member Typedef Documentation

ExternalBody

using server::handlers::CustomHandlerException::ExternalBody = handlers::ExternalBody

Definition at line 216 of file exceptions.hpp.

ExtraHeaders

using server::handlers::CustomHandlerException::ExtraHeaders = handlers::ExtraHeaders

Definition at line 217 of file exceptions.hpp.

HandlerErrorCode

using server::handlers::CustomHandlerException::HandlerErrorCode = handlers::HandlerErrorCode

Definition at line 213 of file exceptions.hpp.

InternalMessage

using server::handlers::CustomHandlerException::InternalMessage = handlers::InternalMessage

Definition at line 215 of file exceptions.hpp.

ServiceErrorCode

using server::handlers::CustomHandlerException::ServiceErrorCode = handlers::ServiceErrorCode

Definition at line 214 of file exceptions.hpp.

Constructor & Destructor Documentation

CustomHandlerException() [1/4]

template<typename... Args>

server::handlers::CustomHandlerException::CustomHandlerException ( HandlerErrorCode  handler_code, Args &&...  args  )

inline

Construct manually from a set of (mostly optional) arguments, which describe the error details.

Allowed arguments

• HandlerErrorCode - defaults for other fields are derived from it
• ServiceErrorCode - used e.g. in JSON error format
• http::HttpStatus
• InternalMessage - for logs
• ExternalBody
• ExtraHeaders
• formats::json::Value - details for JSON error format
• a message builder, see below

Example:

TEST(CustomHandlerException, DirectSample) {
  auto exc = server::handlers::ClientError(
      server::handlers::InternalMessage{"Spam detected, criterion: too many "
                                        "repetitions (42, we only allow 10)"},
      server::handlers::ExternalBody{"Failed to post: spam detected"});
 
  EXPECT_EQ(exc.GetCode(), server::handlers::HandlerErrorCode::kClientError);
  EXPECT_EQ(server::http::GetHttpStatus(exc),
            server::http::HttpStatus::kBadRequest);
  EXPECT_THAT(exc.GetExternalErrorBody(),
              testing::HasSubstr("Failed to post: spam detected"));
  EXPECT_THAT(exc.what(), testing::HasSubstr("42, we only allow 10"));
}

Message builders

A message builder is a class that satisfies the following requirements:

• provides a GetExternalBody() const function to form an external body
• has an optional kIsExternalBodyFormatted set to true to forbid changing the external body
• has an optional GetServiceCode() const function to return machine readable error code
• has an optional GetInternalMessage() const function to form an message for logging an error

Some message builder data can be overridden by explicitly passed args, if these args go after the message builder.

Example:

class CustomErrorBuilder {
 public:
  static constexpr bool kIsExternalBodyFormatted = true;
 
  CustomErrorBuilder(std::string status, std::string msg) {
    formats::json::ValueBuilder error;
    error["code"] = std::move(status);
    error["message"] = std::move(msg);
    json_error_body = formats::json::ToString(error.ExtractValue());
  }
 
  std::string GetExternalBody() const { return json_error_body; }
 
 private:
  std::string json_error_body;
};
 
TEST(CustomHandlerException, BuilderSample) {
  auto exc = server::handlers::ClientError(
      CustomErrorBuilder{"Bad Request", "Something went wrong"});
 
  EXPECT_EQ(exc.GetCode(), server::handlers::HandlerErrorCode::kClientError);
  EXPECT_EQ(exc.what(), std::string{"Client error"}) << "Log message";
 
  auto json = formats::json::FromString(
      R"({"code":"Bad Request","message":"Something went wrong"})");
  EXPECT_EQ(formats::json::FromString(exc.GetExternalErrorBody()), json);
}

Definition at line 253 of file exceptions.hpp.

CustomHandlerException() [2/4]

server::handlers::CustomHandlerException::CustomHandlerException ( HandlerErrorCode  handler_code )

inlineexplicit

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 258 of file exceptions.hpp.

CustomHandlerException() [3/4]

server::handlers::CustomHandlerException::CustomHandlerException ( ServiceErrorCode  service_code, ExternalBody  external_body, InternalMessage  internal_message, HandlerErrorCode  handler_code, ExtraHeaders  headers = {}, formats::json::Value  details = {}  )

inline

Deprecated:

Use the variadic constructor above instead.

Definition at line 263 of file exceptions.hpp.

CustomHandlerException() [4/4]

template<typename MessageBuilder , typename = std::enable_if_t<impl::kIsMessageBuilder<MessageBuilder>>>

server::handlers::CustomHandlerException::CustomHandlerException ( MessageBuilder &&  builder, HandlerErrorCode  handler_code  )

inline

Deprecated:

Use the variadic constructor above instead.

Definition at line 278 of file exceptions.hpp.

Member Function Documentation

GetCode()

HandlerErrorCode server::handlers::CustomHandlerException::GetCode ( ) const

inline

Definition at line 294 of file exceptions.hpp.

GetDetails()

const formats::json::Value & server::handlers::CustomHandlerException::GetDetails ( ) const

inline

Definition at line 306 of file exceptions.hpp.

GetExternalErrorBody()

const std::string & server::handlers::CustomHandlerException::GetExternalErrorBody ( ) const

inline

Definition at line 302 of file exceptions.hpp.

GetExtraHeaders()

const Headers & server::handlers::CustomHandlerException::GetExtraHeaders ( ) const

inline

Definition at line 308 of file exceptions.hpp.

GetServiceCode()

const std::string & server::handlers::CustomHandlerException::GetServiceCode ( ) const

inline

Definition at line 296 of file exceptions.hpp.

IsExternalErrorBodyFormatted()

bool server::handlers::CustomHandlerException::IsExternalErrorBodyFormatted ( ) const

inline

Definition at line 298 of file exceptions.hpp.

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The documentation for this class was generated from the following file:

• userver/server/handlers/exceptions.hpp