Class: Lumberjack::Template

Inherits:
Object
  • Object
show all
Defined in:
lib/lumberjack/template.rb

Overview

A template converts entries to strings. Templates can contain the following place holders to reference log entry values:

  • :time

  • :severity

  • :progname

  • :tags

  • :message

Any other words prefixed with a colon will be substituted with the value of the tag with that name. If your tag name contains characters other than alpha numerics and the underscore, you must surround it with curly brackets: ‘:httphttp.request-id`.

Constant Summary collapse

TEMPLATE_ARGUMENT_ORDER = 
%w[:time :severity :progname :pid :message :tags].freeze
MILLISECOND_TIME_FORMAT = 
"%Y-%m-%dT%H:%M:%S.%3N"
MICROSECOND_TIME_FORMAT = 
"%Y-%m-%dT%H:%M:%S.%6N"
PLACEHOLDER_PATTERN = 
/:(([a-z0-9_]+)|({[^}]+}))/i.freeze

Instance Method Summary collapse

Constructor Details

#initialize(first_line, options = {}) ⇒ Template

Create a new template from the markup. The first_line argument is used to format only the first line of a message. Additional lines will be added to the message unformatted. If you wish to format the additional lines, use the :additional_lines options to specify a template. Note that you’ll need to provide the line separator character in this template if you want to keep the message on multiple lines.

The time will be formatted as YYYY-MM-DDTHH:MM:SSS.SSS by default. If you wish to change the format, you can specify the :time_format option which can be either a time format template as documented in Time#strftime or the values :milliseconds or :microseconds to use the standard format with the specified precision.

Messages will have white space stripped from both ends.

Parameters:

  • first_line (String) —

    The template to use to format the first line of a message.

  • options (Hash) (defaults to: {}) —

    The options for the template.



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# File 'lib/lumberjack/template.rb', line 36

def initialize(first_line, options = {})
  @first_line_template, @first_line_tags = compile(first_line)
  additional_lines = options[:additional_lines] || "#{Lumberjack::LINE_SEPARATOR}:message"
  @additional_line_template, @additional_line_tags = compile(additional_lines)
  # Formatting the time is relatively expensive, so only do it if it will be used
  @template_include_time = first_line.include?(":time") || additional_lines.include?(":time")
  self.datetime_format = (options[:time_format] || :milliseconds)
end

Instance Method Details

#call(entry) ⇒ String

Convert an entry into a string using the template.

Parameters:

Returns:

  • (String) —

    The entry converted to a string.



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# File 'lib/lumberjack/template.rb', line 68

def call(entry)
  return entry unless entry.is_a?(LogEntry)

  first_line = entry.message.to_s
  additional_lines = nil
  if first_line.include?(Lumberjack::LINE_SEPARATOR)
    additional_lines = first_line.split(Lumberjack::LINE_SEPARATOR)
    first_line = additional_lines.shift
  end

  formatted_time = @time_formatter.call(entry.time) if @template_include_time
  format_args = [formatted_time, entry.severity_label, entry.progname, entry.pid, first_line]
  tag_arguments = tag_args(entry.tags, @first_line_tags)
  message = (@first_line_template % (format_args + tag_arguments))
  message.rstrip! if message.end_with?(" ")

  if additional_lines && !additional_lines.empty?
    tag_arguments = tag_args(entry.tags, @additional_line_tags) unless @additional_line_tags == @first_line_tags
    additional_lines.each do |line|
      format_args[format_args.size - 1] = line
      line_message = (@additional_line_template % (format_args + tag_arguments)).rstrip
      line_message.rstrip! if line_message.end_with?(" ")
      message << line_message
    end
  end
  message
end

#datetime_format ⇒ String

Get the format used to format the time.

Returns:

  • (String) 


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# File 'lib/lumberjack/template.rb', line 60

def datetime_format
  @time_formatter.format
end

#datetime_format=(format) ⇒ Object

Set the format used to format the time.

Parameters:

  • format (String) —

    The format to use to format the time.



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# File 'lib/lumberjack/template.rb', line 48

def datetime_format=(format)
  if format == :milliseconds
    format = MILLISECOND_TIME_FORMAT
  elsif format == :microseconds
    format = MICROSECOND_TIME_FORMAT
  end
  @time_formatter = Formatter::DateTimeFormatter.new(format)
end