added /daos folder with dao module

daos/dao.coffee

@@ -0,0 +1,67 @@
+#npm install mongodb
+mongodb = require 'mongodb'
+
+###
+Use:
+	connector = new MongoDBConnector 'design_patterns', 'alex.mongohq.com', 100001
+	connector.findAll (err, items) -> res.send items
+###
+class MongoDBConnector
+	# dbName = 'design_patterns'
+	# port = 100001
+	# host = 'alex.mongohq.com'
+	constructor: (@dbName, @host, @port) ->
+		@db = new mongodb.Db(@dbName, new mongodb.Server(@host, @port, {auto_reconnect:true}), {});
+		@db.open (err, p_client) ->
+			@db.authenticate 'admin', '1234', (err) ->
+
+	#call: callback parameters are (err, collection)
+	initTransaction = (callback) ->
+		@db.collection @dbName, callback
+
+
+	#call: callback parameters are (err, items)
+	findAll: (callback) ->
+		initTransaction (err, collection) ->
+			collection.find().toArray (err, items) ->
+				callback err, items
+
+	#call: callback parameters are (err, count)
+	count: (callback) ->
+		initTransaction (err, collection) ->
+			collection.count (err, count) ->
+				callback err, count
+
+	#call: callback parameters are (err, item)
+	findById: (pId, callback) ->
+		initTransaction (err, collection) ->
+			collection.findOne id:pId, (err, item) ->
+				callback err, item
+
+	#call: callback parameters are (err, doc)
+	insert: (pattern, callback) ->
+		initTransaction (err, collection) ->
+			collection.count (err, count) ->
+				pattern.id = count + 1
+				collection.insert pattern, (err, doc) ->
+					callback err, doc
+
+	#call: callback parameters are (err, pattern)
+	update: (pattern, callback) ->
+		initTransaction (err, collection) ->
+			collection.update id:pattern.id,
+				$set:
+					name: pattern.name
+					category: pattern.category
+					intent: pattern.intent
+					motivation: pattern.motivation
+					applicability: pattern.applicability
+					structure: pattern.structure,
+				(err) ->
+					callback err, pattern
+
+	#call: callback parameters are (err, removed)
+	delete: (pId, callback) ->
+		initTransaction (err, collection) ->
+			collection.remove id:pId, (err, removed) ->
+				callback err, removed