Merge pull request #9 from marshallswain/init-with-db

Allow services to share a common db connection.

Author: marshallswain

README.md

@@ -35,17 +35,17 @@ The following options can be passed when creating a new MongoDB service:
 
 General options:
 
-- `collection` - The name of the collection
+- `collection` - The name of the collection or an already-connected collection object.  When using an object, no other options are needed.  See the example below.
 - `connectionString` - A MongoDB connection string
 - `[_id]` (default: `"_id"`) - The id property
 - `username` - MongoDB username
 - `password` - MongoDB password
 
 Connection options (when `connectionString` is not set):
 
+- `db` (default: `"feathers"`) - The name of the database
 - `host` (default: `"localhost"`) - The MongoDB host
 - `port` (default: `27017`) - The MongoDB port
-- `db` (default: `"feathers"`) - The name of the database
 
 MongoDB options:
 
@@ -54,6 +54,25 @@ MongoDB options:
 - `fsync` (default: `false`) - Don't wait for syncing to disk before acknowledgment
 - `safe` (default: `false`) - Safe mode 
 
+## Sharing a MongoDB connection between services
+When creating a new service, the default behavior is to create a new connection to the specified database.  If you would rather share a database connection between multiple services, connect to the database then pass an already-connected collection object in on options.collection.  For example:
+
+```js
+var feathers = require('feathers')
+  , mongo = require('mongoskin')
+  , mongoService = require('feathers-mongodb')
+  , app = feathers();
+
+// First, make the connection.
+var db = mongo.db('mongodb://localhost:27017/my-project');
+
+// Use the same db connection in both of these services.
+app.use('/api/users', mongoService({collection:db.collection('users')}));
+app.use('/api/todos', mongoService({collection:db.collection('todos')}));
+
+app.listen(8080);
+```
+
 ## Extending MongoDB services
 
 To extend the basic MongoDB service there are two options. Either through using [Uberproto's](https://github.com/daffl/uberproto) inheritance mechanism or by using [feathers-hooks](https://github.com/feathersjs/feathers-hooks).

lib/mongodb.js

@@ -20,41 +20,40 @@ var MongoService = Proto.extend({
     this._connect(this.options);
   },
 
-  // NOTE (EK): We create a new database connection for every MongoService.
-  // This may not be good but... in the mean time the rational for this
-  // design is because each user of a MongoService instance could be a separate
-  // app residing on a totally different server.
-
   // TODO (EK): We need to handle replica sets.
   _connect: function(options) {
-    var connectionString = options.connectionString;
-    var ackOptions = {
-      w: options.w || 1,                  // write acknowledgment
-      journal: options.journal || false,  // doesn't wait for journal before acknowledgment
-      fsync: options.fsync || false,       // doesn't wait for syncing to disk before acknowledgment
-      safe: options.safe || false
-    };
-
-    if(!connectionString) {
-      var config = _.extend({
-        host: 'localhost',
-        port: 27017,
-        db: 'feathers'
-      }, options);
-
-      connectionString = config.host + ':' + config.port + '/' + config.db;
-    }
+    if (typeof options.collection === 'string') {
+      var connectionString = options.connectionString;
+      var ackOptions = {
+        w: options.w || 1,                  // write acknowledgment
+        journal: options.journal || false,  // doesn't wait for journal before acknowledgment
+        fsync: options.fsync || false,       // doesn't wait for syncing to disk before acknowledgment
+        safe: options.safe || false
+      };
+
+      if(!connectionString) {
+        var config = _.extend({
+          host: 'localhost',
+          port: 27017,
+          db: 'feathers'
+        }, options);
+
+        connectionString = config.host + ':' + config.port + '/' + config.db;
+      }
 
-    if(options.username && options.password) {
-      connectionString += options.username + ':' + options.password + '@';
-    }
+      if(options.username && options.password) {
+        connectionString += options.username + ':' + options.password + '@';
+      }
 
-    if(options.reconnect) {
-      connectionString += '?auto_reconnect=true';
-    }
+      if(options.reconnect) {
+        connectionString += '?auto_reconnect=true';
+      }
 
-    this.store = mongo.db(connectionString, ackOptions);
-    this.collection = this.store.collection(options.collection);
+      this.store = mongo.db(connectionString, ackOptions);
+      this.collection = this.store.collection(options.collection);
+    } else {
+      this.collection = options.collection;
+    }
   },
 
   find: function(params, cb) {

package.json

@@ -15,7 +15,8 @@
   "author": "Feathers <[email protected]> (http://feathersjs.com)",
   "contributors": [
     "Eric Kryski <[email protected]> (http://erickryski.com)",
-    "David Luecke <[email protected]> (http://neyeon.com)"
+    "David Luecke <[email protected]> (http://neyeon.com)",
+    "Marshall Thompson <[email protected]>"
   ],
   "license": "MIT",
   "bugs": {