updated logging package to accept functions or other non-string objects when logging

pkg/logging/lib/logging.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  */
 library logging;
 
 import 'dart:async';
 import 'dart:collection';
@@ skipping 116 matching lines @@
   /** Whether a message for [value]'s level is loggable in this logger. */
   bool isLoggable(Level value) => (value >= level);
 
   /**
    * Adds a log record for a [message] at a particular [logLevel] if
    * `isLoggable(logLevel)` is true.
    *
    * Use this method to create log entries for user-defined levels. To record a
    * message at a predefined level (e.g. [Level.INFO], [Level.WARNING], etc) you
    * can use their specialized methods instead (e.g. [info], [warning], etc).
+   *
+   * If [message] is a [Function], it will be lazy evaluated. Additionally, if
+   * [message] or its evaluated value is not a [String], then 'toString()' will
+   * be called on it and the result will be logged.
    */
-  void log(Level logLevel, String message, [Object error,
-                                            StackTrace stackTrace]) {
+  void log(Level logLevel, message, [Object error, StackTrace stackTrace]) {
     if (isLoggable(logLevel)) {
+      // If message is a Function, evaluate it.
+      if (message is Function) message = message();
+      // If message is still not a String, call toString().
+      if (message is! String) message = message.toString();
+
       var record = new LogRecord(logLevel, message, fullName, error,
           stackTrace);
 
       if (hierarchicalLoggingEnabled) {
         var target = this;
         while (target != null) {
           target._publish(record);
           target = target.parent;
         }
       } else {
         root._publish(record);
       }
     }
   }
 
   /** Log message at level [Level.FINEST]. */
-  void finest(String message, [Object error, StackTrace stackTrace]) =>
+  void finest(message, [Object error, StackTrace stackTrace]) =>
       log(Level.FINEST, message, error, stackTrace);
 
   /** Log message at level [Level.FINER]. */
-  void finer(String message, [Object error, StackTrace stackTrace]) =>
+  void finer(message, [Object error, StackTrace stackTrace]) =>
       log(Level.FINER, message, error, stackTrace);
 
   /** Log message at level [Level.FINE]. */
-  void fine(String message, [Object error, StackTrace stackTrace]) =>
+  void fine(message, [Object error, StackTrace stackTrace]) =>
       log(Level.FINE, message, error, stackTrace);
 
   /** Log message at level [Level.CONFIG]. */
-  void config(String message, [Object error, StackTrace stackTrace]) =>
+  void config(message, [Object error, StackTrace stackTrace]) =>
       log(Level.CONFIG, message, error, stackTrace);
 
   /** Log message at level [Level.INFO]. */
-  void info(String message, [Object error, StackTrace stackTrace]) =>
+  void info(message, [Object error, StackTrace stackTrace]) =>
       log(Level.INFO, message, error, stackTrace);
 
   /** Log message at level [Level.WARNING]. */
-  void warning(String message, [Object error, StackTrace stackTrace]) =>
+  void warning(message, [Object error, StackTrace stackTrace]) =>
       log(Level.WARNING, message, error, stackTrace);
 
   /** Log message at level [Level.SEVERE]. */
-  void severe(String message, [Object error, StackTrace stackTrace]) =>
+  void severe(message, [Object error, StackTrace stackTrace]) =>
       log(Level.SEVERE, message, error, stackTrace);
 
   /** Log message at level [Level.SHOUT]. */
-  void shout(String message, [Object error, StackTrace stackTrace]) =>
+  void shout(message, [Object error, StackTrace stackTrace]) =>
       log(Level.SHOUT, message, error, stackTrace);
 
   Stream<LogRecord> _getStream() {
     if (hierarchicalLoggingEnabled || parent == null) {
       if (_controller == null) {
         _controller = new StreamController<LogRecord>.broadcast(sync: true);
       }
       return _controller.stream;
     } else {
       return root._getStream();
@@ skipping 110 matching lines @@
   /** Associated stackTrace (if any) when recording errors messages. */
   final StackTrace stackTrace;
 
   LogRecord(this.level, this.message, this.loggerName, [this.error,
                                                         this.stackTrace])
       : time = new DateTime.now(),
         sequenceNumber = LogRecord._nextNumber++;
 
   String toString() => '[${level.name}] $loggerName: $message';
 }