loggable.rb in semantic_logger-2.1.0

- old
+ new

@@ -8,13 +8,15 @@
 #   and make it accessible via instance methods
 #
 # Example
 #
 #  require 'semantic_logger'
+#  SemanticLogger.default_level = :debug
+#  SemanticLogger.add_appender(STDOUT)
 #
 #  class ExternalSupplier
-#    # Lazy load 'logger' class variable on first use
+#    # Create class and instance logger methods
 #    include SemanticLogger::Loggable
 #
 #    def call_supplier(amount, name)
 #      logger.debug "Calculating with amount", { :amount => amount, :name => name }
 #
@@ -31,17 +33,67 @@
       base.class_eval do
         # Thread safe class variable initialization
         include SyncAttr
 
         sync_cattr_reader :logger do
-          SemanticLogger::Logger.new(self)
+          SemanticLogger[self]
         end
       end
     end
 
     # Also make the logger available as an instance method MixIn
+    # The class logger can be replaced using an instance specific #logger= below
     def logger
-      self.class.logger
+      @semantic_logger ||= self.class.logger
+    end
+
+    # Set instance specific logger
+    #
+    # By default instances of the class will use the class logger. Sometimes it
+    # is useful to be able to add instance specific logging data to the class name.
+    #
+    # For example, server or host_name that the class instance is using.
+    #
+    # Example:
+    #   require 'semantic_logger'
+    #   SemanticLogger.default_level = :debug
+    #   SemanticLogger.add_appender(STDOUT)
+    #
+    #   class MyClass
+    #     include SemanticLogger::Loggable
+    #
+    #     def self.my_name=(my_name)
+    #       # Use class level logger that only logs class name
+    #       logger.info "My name is changed to #{my_name}"
+    #
+    #       @@my_name = my_name
+    #     end
+    #
+    #     def initialize(host_name)
+    #       # Add host_name to every log entry in this logging instance
+    #       self.logger = SemanticLogger["#{self.class.name} [#{host_name}]"]
+    #
+    #       logger.info "Started server"
+    #     end
+    #
+    #     def check
+    #       logger.debug "Checking..."
+    #     end
+    #   end
+    #
+    #   MyClass.my_name = "Joe"
+    #
+    #   mine = MyClass.new('server.com')
+    #   mine.check
+    #
+    # # Generates the following log output:
+    #
+    # 2013-04-02 15:08:42.368574 I [37279:70198560687720] MyClass -- My name is changed to Joe
+    # 2013-04-02 15:08:42.369934 I [37279:70198560687720] MyClass [server.com] -- Started server
+    # 2013-04-02 15:08:42.371171 D [37279:70198560687720] MyClass [server.com] -- Checking...
+    #
+    def logger=(logger)
+      @semantic_logger = logger
     end
 
   end
 end
\ No newline at end of file