libdap::Error Class Reference

A class for error processing. More...

#include <Error.h>

Inheritance diagram for libdap::Error:

Public Member Functions
	Error ()
	Error (const Error &copy_from) noexcept
	Error (ErrorCode ec, std::string msg, std::string file="", int line=0)
	Error (std::string msg, std::string file="", int line=0)
ErrorCode	get_error_code () const
std::string	get_error_message () const
std::string	get_file () const
int	get_line () const
bool	OK () const
	Is the Error object valid? More...
Error &	operator= (const Error &rhs)
bool	parse (FILE *fp)
	Parse an Error object. More...
void	print (FILE *out) const
void	print (std::ostream &out) const
void	set_error_code (ErrorCode ec=undefined_error)
void	set_error_message (std::string msg="")
void	set_file (std::string f)
void	set_line (int l)
const char *	what () const noexcept override
	The pointer is valid only for the lifetime of the Error instance. jhrg 9/22/20. More...

Protected Attributes
ErrorCode	_error_code
std::string	_error_message
std::string	d_file
int	d_line {}

Detailed Description

A class for error processing.

The Error class is used to transport error information from the server to the client within libdap. This class is also the base class for all the errors thrown by methods in the DAP, so catching Error will catch all DAP throws. Errors consist of an error code and a string. The code can be used to quickly distinguish between certain common errors while the string is used to convey information about the error to the user. The error code should never be displayed to the user.

This class is used on both clients and servers. The print() and parse() methods are used to send the object back and forth.

Note

A past version of this class supported the notion of an error correcting program (Tcl, Java, ...) that could be sent from the server to the client to help users correct the error and resubmit the request. This never worked well in practice and that feature of the class is deprecated.

Author

jhrg

Definition at line 93 of file Error.h.

Constructor & Destructor Documentation

Error() [1/4]

libdap::Error::Error ( )

inline

Specializations of Error should use this to set the error code and message.

Definition at line 103 of file Error.h.

Error() [2/4]

libdap::Error::Error ( ErrorCode  ec, std::string  msg, std::string  file = "", int  line = 0  )

inline

Create an instance with a specific code and message string. This ctor provides a way to to use any code and string you'd like. The code can be one of the standard codes or it may be specific to your server. Thus a client which can tell it's dealing with a specific type of server can use the code accordingly. In general, clients simply show the error message to users or write it to a log file.

Parameters

ec	The error code
msg	The error message string.
file	Name of the source file (optional)
line	Line in the source file (optional)

Definition at line 117 of file Error.h.

Error() [3/4]

libdap::Error::Error ( std::string  msg, std::string  file = "", int  line = 0  )

inlineexplicit

Create an instance with a specific message. The error code is set to unknown_error.

Parameters

msg	The error message.
file	Name of the source file (optional)
line	Line in the source file (optional)

See also

ErrorCode

Definition at line 129 of file Error.h.

Error() [4/4]

libdap::Error::Error ( const Error &  copy_from )

inlinenoexcept

Definition at line 133 of file Error.h.

Member Function Documentation

get_error_code()

ErrorCode libdap::Error::get_error_code

(

)

const

Get the ErrorCode for this instance.

Definition at line 214 of file Error.cc.

get_error_message()

string libdap::Error::get_error_message

(

)

const

Return the current error message.

Definition at line 243 of file Error.cc.

get_file()

std::string libdap::Error::get_file ( ) const

inline

Definition at line 150 of file Error.h.

get_line()

int libdap::Error::get_line ( ) const

inline

Definition at line 152 of file Error.h.

OK()

bool libdap::Error::OK

(

)

const

Is the Error object valid?

Use this function to determine whether an Error object is valid. To be a valid, an Error object must either be: 1) empty or contain a message and a code.

Returns

TRUE if the object is valid, FALSE otherwise.

Definition at line 100 of file Error.cc.

operator=()

Error & libdap::Error::operator=

(

const Error &

rhs

)

Definition at line 74 of file Error.cc.

parse()

bool libdap::Error::parse

(

FILE *

fp

)

Parse an Error object.

Given an input stream (FILE *) fp, parse an Error object from stream. Values for fields of the Error object are parsed and this is set accordingly. This is how a client program receives an error object from a server.

Parameters

fp	A valid file pointer to an input stream.

Returns

TRUE if no error was detected, FALSE otherwise.

Definition at line 123 of file Error.cc.

print() [1/2]

void libdap::Error::print

(

FILE *

out

)

const

Creates a printable representation of the Error object. It is suitable for framing, and also for printing and sending over a network.

The printed representation produced by this function can be parsed by the parse() member function. Thus parse and print form a symmetrical pair that can be used to send and receive an Error object over the network in a MIME document.

Parameters

out	A pointer to the output stream on which the Error object is to be rendered.

Definition at line 165 of file Error.cc.

print() [2/2]

void libdap::Error::print

(

std::ostream &

out

)

const

Creates a printable representation of the Error object. It is suitable for framing, and also for printing and sending over a network.

The printed representation produced by this function can be parsed by the parse() member function. Thus parse and print form a symmetrical pair that can be used to send and receive an Error object over the network in a MIME document.

Parameters

strm	A reference to the output stream on which the Error object is to be rendered.

Definition at line 194 of file Error.cc.

set_error_code()

void libdap::Error::set_error_code

(

ErrorCode

ec = undefined_error

)

Set the ErrorCode. If the current error message has not been set, use ec to set the error message. The resulting error message string is the same as the ErrorCode name. If ec is not within the range of values for an OPeNDAP ErrorCode, the error message is left unchanged.

Parameters

ec	The new ErrorCode value.

Definition at line 227 of file Error.cc.

set_error_message()

void libdap::Error::set_error_message

(

std::string

msg = ""

)

Set the error message.

Definition at line 252 of file Error.cc.

set_file()

void libdap::Error::set_file ( std::string  f )

inline

Definition at line 151 of file Error.h.

set_line()

void libdap::Error::set_line ( int  l )

inline

Definition at line 153 of file Error.h.

what()

const char * libdap::Error::what ( ) const

inlineoverridenoexcept

The pointer is valid only for the lifetime of the Error instance. jhrg 9/22/20.

Definition at line 156 of file Error.h.

Member Data Documentation

_error_code

ErrorCode libdap::Error::_error_code

protected

Definition at line 96 of file Error.h.

_error_message

std::string libdap::Error::_error_message

protected

Definition at line 97 of file Error.h.

d_file

std::string libdap::Error::d_file

protected

Definition at line 98 of file Error.h.

d_line

int libdap::Error::d_line {}

protected

Definition at line 99 of file Error.h.

---

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

• Error.h
• Error.cc