Skip to Content Skip to Search

Active Support Proxy Logger ↑

The proxy logger, is a logger that forwards all received logs to another logger, but has its own independent severity level.

This is useful when you want some library you have no control over to use the same logger as the rest of your application, but to have a different severity level because it is logging too much:

SomeLibrary.logger = ActiveSupport::ProxyLogger.new(Rails.logger, :error)

Almost all of the standard Logger interface is supported.

Note that the proxy logger can only surpress some logs, if the proxy severity is lower than the severity of the proxied logger, the logs won’t be emitted.

Methods
#
A
C
D
E
F
I
L
N
R
U
W
Included Modules

Class Public methods

new(logger, level = ::Logger::DEBUG)

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 26
def initialize(logger, level = ::Logger::DEBUG)
  super()
  @logger = logger
  @level = ::Logger::Severity.coerce(level)
end

Instance Public methods

<<(msg)

Forward the given msg to the underlying logger with no formatting returns the number of characters written, or nil if the underlying logger is nil:

logger = ProxyLogger.new(Logger.new($stderr))
logger << 'My message.' # => 10

Output:

My message.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 140
def <<(msg)
  if @logger
    @logger << msg
  end
end

add(severity, ...)

Creates a log entry, which may or may not be written to the log, depending on the entry’s severity and on the log level.

Examples:

logger = ActiveSupport::ProxyLogger.new(Logger.new($stderr), :error)
logger.add(Logger::INFO, 'Will not show')
logger.add(Logger::ERROR, 'No good')
logger.add(Logger::ERROR, 'No good', 'gnum')

Output:

E, [2022-05-12T16:25:55.349414 #36328] ERROR -- mung: No good
E, [2022-05-12T16:26:35.841134 #36328] ERROR -- gnum: No good

These convenience methods have implicit severity:

Also aliased as: log

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 119
def add(severity, ...)
  severity ||= UNKNOWN
  if @logger && severity >= level
    @logger.add(severity, ...)
  else
    true
  end
end

close()

Closes the logger; returns nil: Further logs won’t be emitted.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 51
def close
  @logger = nil
end

debug(progname = nil, &block)

Equivalent to calling add with severity Logger::DEBUG.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 147
def debug(progname = nil, &block)
  add(DEBUG, nil, progname, &block)
end

debug!()

Sets the log level to Logger::DEBUG.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 65
def debug!; self.level = DEBUG; end

debug?()

Returns true if the log level allows entries with severity Logger::DEBUG to be written, false otherwise.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 62
def debug?; level <= DEBUG; end

error(progname = nil, &block)

Equivalent to calling add with severity Logger::ERROR.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 164
def error(progname = nil, &block)
  add(ERROR, nil, progname, &block)
end

error!()

Sets the log level to Logger::ERROR.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 86
def error!; self.level = ERROR; end

error?()

Returns true if the log level allows entries with severity Logger::ERROR to be written, false otherwise.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 83
def error?; level <= ERROR; end

fatal(progname = nil, &block)

Equivalent to calling add with severity Logger::FATAL.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 170
def fatal(progname = nil, &block)
  add(FATAL, nil, progname, &block)
end

fatal!()

Sets the log level to Logger::FATAL.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 93
def fatal!; self.level = FATAL; end

fatal?()

Returns true if the log level allows entries with severity Logger::FATAL to be written, false otherwise.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 90
def fatal?; level <= FATAL; end

info(progname = nil, &block)

Equivalent to calling add with severity Logger::INFO.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 152
def info(progname = nil, &block)
  add(INFO, nil, progname, &block)
end

info!()

Sets the log level to Logger::INFO.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 72
def info!; self.level = INFO; end

info?()

Returns true if the log level allows entries with severity Logger::INFO to be written, false otherwise.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 69
def info?; level <= INFO; end

level()

Logging severity threshold (e.g. Logger::INFO).

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 33
def level
  local_level || @level
end

level=(severity)

Sets the log level; returns severity.

Argument severity may be an integer, a string, or a symbol:

logger.level = Logger::ERROR # => 3
logger.level = 3             # => 3
logger.level = 'error'       # => "error"
logger.level = :error        # => :error

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 45
def level=(severity)
  @level = ::Logger::Severity.coerce(severity)
end

log(severity, ...)

Alias for: add

reopen(logger)

Change the underlying logger.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 56
def reopen(logger)
  @logger = logger
end

unknown(progname = nil, &block)

Equivalent to calling add with severity Logger::UNKNOWN.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 176
def unknown(progname = nil, &block)
  add(UNKNOWN, nil, progname, &block)
end

warn(progname = nil, &block)

Equivalent to calling add with severity Logger::WARN.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 158
def warn(progname = nil, &block)
  add(WARN, nil, progname, &block)
end

warn!()

Sets the log level to Logger::WARN.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 79
def warn!; self.level = WARN; end

warn?()

Returns true if the log level allows entries with severity Logger::WARN to be written, false otherwise.

Source: show | on GitHub 

# File activesupport/lib/active_support/proxy_logger.rb, line 76
def warn?; level <= WARN; end