The Appender
class is provides methods for appending log
events to a logging destination. The log events are formatted into strings
using a Layout.
All other Appenders inherit from this class
which provides stub methods. Each subclass should provide a
write
method that will write log messages to the logging
destination.
A private sync
method is provided for use by subclasses. It is
used to synchronize writes to the logging destination, and can be used by
subclasses to synchronize the closing or flushing of the logging
destination.
Creates a new appender using the given name. If no Layout is specified, then a Basic layout will be used. Any logging header supplied by the layout will be written to the logging destination when the Appender is created.
Options:
:layout => the layout to use when formatting log events :level => the level at which to log
# File lib/logging/appender.rb, line 35 def initialize( name, opts = {} ) ::Logging.init unless ::Logging.const_defined? :MAX_LEVEL_LENGTH @name = name.to_s @closed = false self.layout = opts.getopt(:layout, ::Logging::Layouts::Basic.new) self.level = opts.getopt(:level) @mutex = ReentrantMutex.new header = @layout.header unless header.nil? || header.empty? begin write(header) rescue StandardError => err ::Logging.log_internal(-2) {err} end end ::Logging::Appenders[@name] = self end
Write the given string to the logging destination "as is" -- no layout formatting will be performed.
# File lib/logging/appender.rb, line 89 def <<( str ) if @closed raise RuntimeError, "appender '<#{self.class.name}: #{@name}>' is closed" end unless @level >= ::Logging::LEVELS.length begin write(str) rescue StandardError => err ::Logging.log_internal(-2) {err} end end self end
Write the given event to the logging destination. The log event will be processed through the Layout associated with the Appender.
# File lib/logging/appender.rb, line 64 def append( event ) if @closed raise RuntimeError, "appender '<#{self.class.name}: #{@name}>' is closed" end # only append if the event level is less than or equal to the configured # appender level unless @level > event.level begin write(event) rescue StandardError => err ::Logging.log_internal(-2) {err} end end self end
Close the appender and writes the layout footer to the logging destination
if the footer flag is set to true
. Log events will no
longer be written to the logging destination after the appender is closed.
# File lib/logging/appender.rb, line 168 def close( footer = true ) return self if @closed ::Logging::Appenders.remove(@name) @closed = true flush if footer footer = @layout.footer unless footer.nil? || footer.empty? begin write(footer) rescue StandardError => err ::Logging.log_internal(-2) {err} end end end self end
Returns true
if the appender has been closed; returns
false
otherwise. When an appender is closed, no more log
events can be written to the logging destination.
# File lib/logging/appender.rb, line 195 def closed? @closed end
Call flush
to force an appender to write out any buffered log
events. Similar to IO#flush, so use in a similar fashion.
# File lib/logging/appender.rb, line 214 def flush self end
Returns a string representation of the appender.
# File lib/logging/appender.rb, line 223 def inspect "<%s:0x%x name=\"%s\">" % [ self.class.name.sub(%r^Logging::/, ''), self.object_id, self.name ] end
call-seq
appender.layout = Logging::Layouts::Basic.new
Sets the layout to be used by this appender.
# File lib/logging/appender.rb, line 152 def layout=( layout ) unless layout.kind_of? ::Logging::Layout raise TypeError, "#{layout.inspect} is not a kind of 'Logging::Layout'" end @layout = layout end
Set the level for this appender; log events below this level will be
ignored by this appender. The level can be either a String
, a
Symbol
, or a Fixnum
. An
ArgumentError
is raised if this is not the case.
There are two special levels -- "all" and "off". The former will enable recording of all log events. The latter will disable the recording of all events.
Example:
appender.level = :debug appender.level = "INFO" appender.level = 4 appender.level = 'off' appender.level = :all
These produce an ArgumentError
appender.level = Object appender.level = -1 appender.level = 1_000_000_000_000
# File lib/logging/appender.rb, line 131 def level=( level ) lvl = case level when String, Symbol; ::Logging::level_num(level) when Fixnum; level when nil; 0 else raise ArgumentError, "level must be a String, Symbol, or Integer" end if lvl.nil? or lvl < 0 or lvl > ::Logging::LEVELS.length raise ArgumentError, "unknown level was given '#{level}'" end @level = lvl end
Reopen the connection to the underlying logging destination. If the connection is currently closed then it will be opened. If the connection is currently open then it will be closed and immediately opened.
# File lib/logging/appender.rb, line 203 def reopen @closed = false self end