Logger::LoggerPattern Class Reference

Implements pattern parsing and substitution. More...

#include <Logger.qm.dox.h>

Inheritance diagram for Logger::LoggerPattern:

Public Member Methods
	constructor (string pattern)
	Creates the object. More...
string	format (auto data)
	Formats the event record with the current pattern. More...
string	getPattern ()
	Returns the current pattern.
	setPattern (string value)
	Sets the new pattern. More...

Public Attributes
const	ESCAPE_CHAR = "%"
	format escape character

Private Member Methods
abstract *string	resolveField (auto data, string key, *string option)
	Returns a formatted string for an input pattern. More...

Private Attributes
list< auto >	parsedPattern
	parsed pattern; list elements may be strings or hashes

Private:Internal Attributes
string	origPattern
	pattern

Detailed Description

Implements pattern parsing and substitution.

The pattern defines fields to be substituted with real values

The pattern format is:

%[<modifiers>] <word> [{<option>}]
modifiers := [0-9.-]*
word := [a-zA-Z]+
option := [^}]*

When a word (i.e. longer than one char) key without curly brackets is not found then in the next step is resolved its first char, e.g. "%parchive" the first step tries to resolve "parchive" key and if not resolved the second step "p" key. To parse in key if single step delimit a word from the next character, use curly brackets, i.e. empty option, e.g. "%p{}archive". If a key is not resolved then exception is raised.

The following table covers various modifiers and scenarios:

Format modifier	left justify	minimum width	maximum width	comment
%20c	false	20	none	Left pad with spaces if the category name is less than 20 characters long
%-20c	true	20	none	Right pad with spaces if the category name is less than 20 characters long
%.30c	NA	none	30	Truncate from the beginning if the category name is longer than 30 characters
%20.30c	false	20	30	Left pad with spaces if the category name is shorter than 20 characters. However, if the category name is longer than 30 characters, then truncate from the beginning
%-20.30c	true	20	30	Right pad with spaces if the category name is shorter than 20 characters. However, if the category name is longer than 30 characters, then truncate from the beginning

Member Function Documentation

constructor()

Logger::LoggerPattern::constructor

(

string

pattern

)

Creates the object.

Parameters

pattern

the logger pattern

Exceptions

LOGGER-ERROR

when pattern is invalid

format()

string Logger::LoggerPattern::format

(

auto

data

)

Formats the event record with the current pattern.

Parameters

data	is passed to resolveField()

Exceptions

LOGGER-ERROR

when a key is not resolved

resolveField()

abstract *string Logger::LoggerPattern::resolveField ( auto  data, string  key, *string  option  )

privatepure virtual

Returns a formatted string for an input pattern.

Parameters

data	input context reference data
key	the format character
option	the format option value, if any

Returns

the formatted string or nothing if the key is not resolved

Implemented in Logger::LoggerAppenderFileRotate, Logger::LoggerAppenderFileRing, Logger::LoggerAppenderFileArchive, and Logger::LoggerLayoutPattern.

setPattern()

Logger::LoggerPattern::setPattern

(

string

value

)

Sets the new pattern.

Parameters

value

the logger pattern

Exceptions

LOGGER-ERROR

when pattern is invalid