Logger.debug_var

debug_var.rb

require 'logger'

class Logger
  def debug_var(ctx, *vars)
    # get Class name & decide method type
    class_name = ctx.eval("self.class").to_s
    if class_name != "Class"
      sep = "#"
    else
      class_name = ctx.eval("self.name")
      sep = "."
    end

    # get method name
    /^(.+?):(\d+)(?::in `(.*)')?/.match(caller.first)
    method_name = $3 ? "#{$3}" : ""

    # create debug message as Array
    message_a = vars.map {|var| "#{var} => #{ctx.eval(var.to_s).inspect}" }

    debug(class_name + sep + method_name) { message_a.join(", ") }
  end
end

class Foo
  def foo(str)
    log = Logger.new($stdout)
    log.datetime_format = "%Y-%m-%d %H:%M:%S"
    #log.level = Logger::WARN unless $DEBUG

    log.debug_var binding, :str
  end

  def self.bar(str1, str2)
    log = Logger.new($stdout)
    log.debug_var binding, :str1, :str2
  end
end

Foo.new.foo("test")
Foo.bar("static", "multi_args")

# >> D, [2011-03-07 22:02:28#68012] DEBUG -- Foo#foo: str => "test"
# >> D, [2011-03-07T22:02:28.762433 #68012] DEBUG -- Foo.bar: str1 => "static", str2 => "multi_args"