log4cxx::FMTLayout Class Reference

The FMTLayout class uses libfmt to layout messages. More...

#include <fmtlayout.h>

Inheritance diagram for log4cxx::FMTLayout:

Public Member Functions
	FMTLayout ()
	FMTLayout (const LogString &pattern)
	~FMTLayout ()
void	setConversionPattern (const LogString &conversionPattern)
	Set the ConversionPattern option.
LogString	getConversionPattern () const
	Returns the value of the ConversionPattern option.
void	format (LogString &output, const spi::LoggingEventPtr &event, helpers::Pool &pool) const override
	Returns the log statement in a format consisting of the level, followed by " - " and then the message.
bool	ignoresThrowable () const override
	If the layout handles the throwable object contained within LoggingEvent, then the layout should return false.
void	activateOptions (helpers::Pool &) override
	Activate the options that were previously set with calls to option setters.
void	setOption (const LogString &, const LogString &) override
	Set option to value.
Public Member Functions inherited from log4cxx::Layout
virtual	~Layout ()
virtual void	format (LogString &output, const spi::LoggingEventPtr &event, log4cxx::helpers::Pool &pool) const =0
	Implement this method to create your own layout format.
virtual LogString	getContentType () const
	Returns the content type output by this layout.
virtual void	appendHeader (LogString &output, log4cxx::helpers::Pool &p)
	Append the header for the layout format.
virtual void	appendFooter (LogString &output, log4cxx::helpers::Pool &p)
	Append the footer for the layout format.
virtual bool	ignoresThrowable () const =0
	If the layout handles the throwable object contained within LoggingEvent, then the layout should return false.
Public Member Functions inherited from log4cxx::spi::OptionHandler
virtual	~OptionHandler ()
virtual void	activateOptions (helpers::Pool &p)=0
	Activate the options that were previously set with calls to option setters.
virtual void	setOption (const LogString &option, const LogString &value)=0
	Set option to value.
Public Member Functions inherited from log4cxx::helpers::Object
virtual	~Object ()
virtual const helpers::Class &	getClass () const =0
virtual bool	instanceof (const Class &clazz) const =0
virtual const void *	cast (const Class &clazz) const =0

Additional Inherited Members
Protected Member Functions inherited from log4cxx::Layout
size_t	getFormattedEventCharacterCount () const
	The expected length of a formatted event excluding the message text.

Detailed Description

The FMTLayout class uses libfmt to layout messages.

This is an alternative to the PatternLayout class. Most of the standard PatternLayout arguments are also accepted as arguments, so that you can easily convert a PatternLayout to a FMTLayout. For example, given the following PatternLayout:

c %-5p - mn

which outputs something like:

root INFO  - Hello there!

The equivalent FMTLayout can be written as:

{c} {p:<5} - {m}{n}

Or more verbosely as:

{logger} {level:<5} - {message}{newline}

All replacements are done using the named arguments feature of {fmt}.

The recognized conversion strings are:

Conversion string	Effect
c logger	Used to output the logger of the logging event. Unlike PatternConverter, this does not take a parameter to shorten the name of the logger.
C class	Used to output the class of the issuer of the logging event if the compiler used supports a macro to retrieve the method of the currently compiled line and if the LOG4CXX_TRACE-like macros are used to issue a logging request. In this case the macro LOG4CXX_* is expanded at compile time to generate location info of the logging event and adds the method name, besides file and line, if available. In most cases the provided method contains the classname and can therefore be retrieved form the location info as needed. Currently supported compilers are those from Microsoft, GNU-C and Borland.
f shortfilename	Used to output the short file name where the logging request was issued.
F filename	Used to output the file name where the logging request was issued.
l location	Used to output location information of the caller which generated the logging event.
L line	Used to output the line number from where the logging request was issued.
m message	Used to output the application supplied message associated with the logging event.
M method	Used to output the method of the issuer of the logging event if the compiler used supports a macro to retrieve the method of the currently compiled line and if the LOG4CXX_TRACE-like macros are used to issue a logging request. In this case the macro LOG4CXX_* is expanded at compile time to generate location info of the logging event and adds the method name, besides file and line, if available. In most cases the provided method contains the classname which is ignored in every attempt to retrieve the method from the location info. Currently supported compilers are those from Microsoft, GNU-C and Borland.
n newline	Outputs the platform dependent line separator character or characters. This conversion character offers practically the same performance as using non-portable line separator strings such as "\n", or "\r\n". Thus, it is the preferred way of specifying a line separator.
p level	Used to output the level of the logging event.
r	Used to output the number of milliseconds elapsed since the start of the application until the creation of the logging event.
t thread	Used to output the ID of the thread that generated the logging event.
T threadname	Used to output the name of the thread that generated the logging event. May not be available on all platforms.
x ndc	Used to output the NDC (nested diagnostic context) associated with the thread that generated the logging event.
mdc[1-6]	Used to output the MDC (mapped diagnostic context) associated with the thread that generated the logging event. The keys must be specified in the configuration for the layout. A maximum of 6 MDC keys are available to be output(mdc1, mdc2, ..., mdc6)

Constructor & Destructor Documentation

FMTLayout() [1/2]

log4cxx::FMTLayout::FMTLayout

(

)

FMTLayout() [2/2]

log4cxx::FMTLayout::FMTLayout

(

const LogString &

pattern

)

~FMTLayout()

log4cxx::FMTLayout::~FMTLayout

(

)

Member Function Documentation

activateOptions()

void log4cxx::FMTLayout::activateOptions ( helpers::Pool &  )

overridevirtual

Activate the options that were previously set with calls to option setters.

No action is performed in this implementation.

Implements log4cxx::spi::OptionHandler.

format()

void log4cxx::FMTLayout::format ( LogString &  output, const spi::LoggingEventPtr &  event, helpers::Pool &  pool  ) const

overridevirtual

Returns the log statement in a format consisting of the level, followed by " - " and then the message.

For example,

 INFO - "A message"

Implements log4cxx::Layout.

getConversionPattern()

LogString log4cxx::FMTLayout::getConversionPattern

(

)

const

Returns the value of the ConversionPattern option.

ignoresThrowable()

bool log4cxx::FMTLayout::ignoresThrowable ( ) const

inlineoverridevirtual

If the layout handles the throwable object contained within LoggingEvent, then the layout should return false.

Otherwise, if the layout ignores throwable object, then the layout should return true.

The SimpleLayout, FMTLayout and PatternLayout return true. The other layouts return false.

Implements log4cxx::Layout.

setConversionPattern()

void log4cxx::FMTLayout::setConversionPattern

(

const LogString &

conversionPattern

)

Set the ConversionPattern option.

This is the string which controls formatting and consists of a mix of literal content and conversion specifiers.

setOption()

void log4cxx::FMTLayout::setOption ( const LogString &  , const LogString &    )

overridevirtual

Set option to value.

Supported options	Supported values	Default value
ConversionPattern	{any}	-

Implements log4cxx::spi::OptionHandler.

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

• fmtlayout.h