[refactor api] Added Logger.prototype.configure which now contains all logic previously in the winston.Logger constructor function.

[api] `winston.Logger` constructor function and `Logger.prototype.configure` set filters in addition to rewriters.

Author: indexzero

README.md

@@ -95,10 +95,35 @@ You can work with this logger in the same way that you work with the default log
   // Adding / Removing Transports
   //   (Yes It's chainable)
   //
-  logger.add(winston.transports.File)
-        .remove(winston.transports.Console);
+  logger
+    .add(winston.transports.File)
+    .remove(winston.transports.Console);
 ```
 
+You can also wholesale reconfigure a `winston.Logger` instance using the `configure` method:
+
+``` js
+  var logger = new winston.Logger({
+    level: 'info',
+    transports: [
+      new (winston.transports.Console)(),
+      new (winston.transports.File)({ filename: 'somefile.log' })
+    ]
+  });
+
+  //
+  // Replaces the previous transports with those in the
+  // new configuration wholesale.
+  //
+  logger.configure({
+    level: 'verbose',
+    transports: [
+      new require('winston-daily-rotate-file')(opts)
+    ]
+  });
+```
+
+
 ### Logging with Metadata
 In addition to logging string messages, winston will also optionally log additional JSON metadata objects. Adding metadata is simple:
 
@@ -641,6 +666,17 @@ Configuring output for this style is easy, just use the `.cli()` method on `wins
 ### Filters and Rewriters
 Filters allow modifying the contents of **log messages**, and Rewriters allow modifying the contents of **log meta** e.g. to mask data that should not appear in logs.
 
+Both filters and rewriters are simple Arrays of functions which can be provided when creating a `new winston.Logger(options)`. e.g.:
+
+``` js
+var logger = new winston.Logger({
+  rewriters: [function (level, msg, meta) { /* etc etc */ }]
+  filters:   [function (msg, meta, level) { /* etc etc */ }]
+})
+```
+
+Like any Array they can also be modified at runtime with no adverse side-effects to the `winston` internals.
+
 ``` js
 logger.filters.push(function(msg, meta, level) {
   return meta.production

lib/winston/logger.js

@@ -22,10 +22,41 @@ var events = require('events'),
 //
 var Logger = exports.Logger = function (options) {
   events.EventEmitter.call(this);
+  this.configure(options);
+};
+
+//
+// Inherit from `events.EventEmitter`.
+//
+util.inherits(Logger, events.EventEmitter);
+
+//
+// ### function configure (options)
+// This will wholesale reconfigure this instance by:
+// 1. Resetting all transports. Older transports will be removed implicitly.
+// 2. Set all other options including levels, colors, rewriters, filters,
+//    exceptionHandlers, etc.
+//
+Logger.prototype.configure = function (options) {
+  var self = this;
+
+  //
+  // If we have already been setup with transports
+  // then remove them before proceeding.
+  //
+  if (Array.isArray(this._names) && this._names.length) {
+    this.clear();
+  }
+
   options = options || {};
+  this.transports = {};
+  this._names     = [];
 
-  var self = this,
-      handleExceptions = false;
+  if (options.transports) {
+    options.transports.forEach(function (transport) {
+      self.add(transport, null, true);
+    });
+  }
 
   //
   // Set Levels and default logging level
@@ -47,40 +78,23 @@ var Logger = exports.Logger = function (options) {
     : true;
 
   //
-  // Setup other intelligent default settings.
+  // Setup internal state as empty Objects even though it is
+  // defined lazily later to ensure a strong existential API contract.
   //
-  this.transports        = {};
-  this.rewriters         = [];
-  this.filters           = [];
   this.exceptionHandlers = {};
   this.profilers         = {};
-  this._names            = [];
-  this._hnames           = [];
-
-  if (options.transports) {
-    options.transports.forEach(function (transport) {
-      self.add(transport, null, true);
-
-      if (transport.handleExceptions) {
-        handleExceptions = true;
-      }
-    });
-  }
 
-  if (Array.isArray(options.rewriters)) {
-    this.rewriters = options.rewriters;
-  }
+  ['rewriters', 'filters'].forEach(function (kind) {
+    self[kind] = Array.isArray(options[kind])
+      ? options[kind]
+      : [];
+  });
 
   if (options.exceptionHandlers) {
     this.handleExceptions(options.exceptionHandlers);
   }
 };
 
-//
-// Inherit from `events.EventEmitter`.
-//
-util.inherits(Logger, events.EventEmitter);
-
 //
 // ### function log (level, msg, [meta], callback)
 // #### @level {string} Level at which to log the message.
@@ -106,7 +120,7 @@ Logger.prototype.log = function (level) {
     msg = new Array(this.levelLength - level.length + 1).join(' ') + msg;
   }
 
-  function onError (err) {
+  function onError(err) {
     if (callback) {
       callback(err);
     }
@@ -115,7 +129,6 @@ Logger.prototype.log = function (level) {
     }
   }
 
-
   if (Object.keys(this.transports).length === 0) {
     return onError(new Error('Cannot log with no transports.'));
   }
@@ -185,7 +198,6 @@ Logger.prototype.log = function (level) {
   }
 
   async.forEach(this._names, emit, cb);
-
   return this;
 };
 
@@ -230,7 +242,7 @@ Logger.prototype.query = function (options, callback) {
   // Helper function to accumulate the results from
   // `queryTransport` into the `results`.
   //
-  function addResults (transport, next) {
+  function addResults(transport, next) {
     queryTransport(transport, function (err, result) {
       //
       // queryTransport could potentially invoke the callback
@@ -456,9 +468,9 @@ Logger.prototype.add = function (transport, options, created) {
 // Remove all transports from this instance
 //
 Logger.prototype.clear = function () {
-  for (var name in this.transports) {
+  Object.keys(this.transports).forEach(function (name) {
     this.remove({ name: name });
-  }
+  }, this);
 };
 
 //

test/logger-test.js

@@ -65,7 +65,29 @@ vows.describe('winton/logger').addBatch({
           assert.equal(level, 'info');
           assert.equal(msg, 'test message');
         }
+      }
+    }
+  }
+}).addBatch({
+  "An instance of winston.Logger": {
+    topic: new (winston.Logger)({ transports: [new (winston.transports.Console)({ level: 'info' })] }),
+    "the configure() method": {
+      "with no options": function (logger) {
+        assert.equal(Object.keys(logger.transports).length, 1);
+        assert.deepEqual(logger._names, ['console']);
+        logger.configure();
+        assert.equal(Object.keys(logger.transports).length, 0);
+        assert.deepEqual(logger._names, []);
       },
+      "with options { transports }": function (logger) {
+        assert.equal(Object.keys(logger.transports).length, 0);
+        assert.deepEqual(logger._names, []);
+        logger.configure({
+          transports: [new winston.transports.Console({ level: 'verbose' })]
+        });
+        assert.equal(Object.keys(logger.transports).length, 1);
+        assert.deepEqual(logger._names, ['console']);
+      }
     }
   }
 }).addBatch({