Class: Ougai::Formatters::Customizable

Inherits:
Base
  • Object
show all
Defined in:
lib/ougai/formatters/customizable.rb

Overview

Ougai log printing can be split in three components:

  1. Main log message: usually with timestamp, log severity and a single line message

  2. Log data: the structured logging component. Can be represented by a Hash

  3. Errors: errors require specific log formatting

Customizable offers a flexible way to handle each component independently by assigning a proc to the following keys:

  1. :format_msg Format message. Proc arguments are |level, datetime, progname, data|. This block must remove the key :msg from data

  2. :format_data Format data. Proc argument is |data|.

  3. :format_err Format err. Proc argument is |data|. The proc must remove the key :err

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(app_name = nil, hostname = nil, opts = {}) ⇒ Customizable

Intialize a formatter

Parameters:

  • app_name (String) (defaults to: nil) —

    application name (execution program name if nil)

  • hostname (String) (defaults to: nil) —

    hostname (hostname if nil)

  • opts (Hash) (defaults to: {}) —

    the initial values of attributes

Options Hash (opts):

  • :trace_max_lines (String) — default: 100 —

    the value of trace_max_lines attribute

  • :plain (String) — default: false —

    the value of plain attribute

  • :excluded_fields (String) — default: [] —

    the value of excluded_fields attribute

  • :color_config (Ougai::Formatters::Colors::Configuration) —

    assign a color configuration.

  • :format_msg (Proc) —

    main message formatter

  • :format_data (Proc) —

    data formatter

  • :format_err (Proc) —

    error formatter



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# File 'lib/ougai/formatters/customizable.rb', line 93

def initialize(app_name = nil, hostname = nil, opts = {})
  aname, hname, opts = Base.parse_new_params([app_name, hostname, opts])
  super(aname, hname, opts)

  # Message logging
  color_config = opts.fetch(:color_config) {
    color_config = Ougai::Formatters::Colors::Configuration.new({})
  }
  @format_msg = opts.fetch(:format_msg) {
    Customizable.default_msg_format(color_config)
  }

  # Data logging
  plain = opts.fetch(:plain) { false }
  excluded_fields = opts[:excluded_fields] || []
  @format_data = opts.fetch(:format_data) {
    Customizable.default_data_format(excluded_fields, plain)
  }

  # Error logging
  trace_indent = opts.fetch(:trace_indent) { 4 }
  @format_err = opts.fetch(:format_err) {
    Customizable.default_err_format(trace_indent)
  }

  # Ensure dependency are present
  load_dependent
end

Class Method Details

.default_data_format(excluded_fields, plain) ⇒ Proc

Define the default error formatting to use which handles field exclusion and plain mode for amazing-print

Parameters:

  • excluded_fields (Array<Symbol>) —

    list of key to exclude from data before printing logs

  • plain (Boolean) —

    parameter to define if Amazing-Print renders in plain mode or not

Returns:

  • (Proc) —

    data formatter



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# File 'lib/ougai/formatters/customizable.rb', line 51

def default_data_format(excluded_fields, plain)
  proc do |data|
    excluded_fields.each { |field| data.delete(field) }
    next nil if data.empty?

    data.ai(plain: plain)
  end
end

.default_err_format(trace_indent = 4) ⇒ Proc

Define the default error formatting to use.

Parameters:

  • trace_indent (Integer) (defaults to: 4) —

    space indentation to prepend before trace content

Returns:

  • (Proc) —

    error formatter



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# File 'lib/ougai/formatters/customizable.rb', line 66

def default_err_format(trace_indent = 4)
  proc do |data|
    next nil unless data.key?(:err)

    err = data.delete(:err)
    err_str = "  #{err[:name]} (#{err[:message]}):"
    err_str += "\n" + (' ' * trace_indent) + err[:stack] if err.key?(:stack)
    err_str
  end
end

.default_msg_format(color_config) ⇒ Proc

Define the default main log message formatting to use. A non-null color configuration has to be provided. The configuration can however be empty

Parameters:

Returns:

  • (Proc) —

    main message formatter



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# File 'lib/ougai/formatters/customizable.rb', line 31

def default_msg_format(color_config)
  proc do |severity, datetime, _progname, data|
    msg = data.delete(:msg)
    severity  = color_config.color(:severity, severity, severity)
    datetime  = color_config.color(:datetime, datetime, severity)
    msg       = color_config.color(:msg, msg, severity)

    "[#{datetime}] #{severity}: #{msg}"
  end
end

Instance Method Details

#_call(severity, time, progname, data) ⇒ String

Format a log entry

Parameters:

  • severity (String) —

    log severity, in capital letters

  • time (Time) —

    timestamp of the log. Is formatted by strftime

  • progname (String) —

    optional program name

  • data (Hash) —

    log data. Main message is stored under the key :msg while errors are logged under the key :err.

Returns:

  • (String) —

    log text, ready to be printed out



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# File 'lib/ougai/formatters/customizable.rb', line 131

def _call(severity, time, progname, data)
  strs = ''.dup
  # Main message
  dt =  format_datetime(time)
  msg_str = @format_msg.call(severity, dt, progname, data)
  strs.concat(msg_str)

  # Error: displayed before additional data
  err_str = @format_err.call(data)
  strs.concat("\n").concat(err_str) unless err_str.nil?

  # Additional data
  data_str = @format_data.call(data)
  strs.concat("\n").concat(data_str) unless data_str.nil?

  strs.concat("\n")
end