Many to Many relationships

.gitignore

@@ -4,4 +4,5 @@ phpunit.phar
 composer.phar
 composer.lock
 *.sublime-project
-*.sublime-workspace
+*.sublime-workspace
+*.project

src/Jenssegers/Mongodb/Model.php

@@ -7,6 +7,7 @@
 use Jenssegers\Mongodb\DatabaseManager as Resolver;
 use Jenssegers\Mongodb\Builder as QueryBuilder;
 use Jenssegers\Mongodb\Relations\BelongsTo;
+use Jenssegers\Mongodb\Relations\BelongsToMany;
 
 use Carbon\Carbon;
 use DateTime;
@@ -199,6 +200,43 @@ public function belongsTo($related, $foreignKey = null, $otherKey = null, $relat
         return new BelongsTo($query, $this, $foreignKey, $otherKey, $relation);
     }
 
+	/**
+	 * Define a many-to-many relationship.
+	 *
+	 * @param  string  $related
+	 * @param  string  $table
+	 * @param  string  $foreignKey
+	 * @param  string  $otherKey
+	 * @return \Illuminate\Database\Eloquent\Relations\BelongsToMany
+	 */
+	public function belongsToMany($related, $collection = null, $foreignKey = null, $otherKey = null)
+	{
+		$caller = $this->getBelongsToManyCaller();
+
+		// First, we'll need to determine the foreign key and "other key" for the
+		// relationship. Once we have determined the keys we'll make the query
+		// instances as well as the relationship instances we need for this.
+		$foreignKey = $foreignKey ?: $this->getForeignKey() . 's';
+
+		$instance = new $related;
+
+		$otherKey = $otherKey ?: $instance->getForeignKey() . 's';
+		// If no table name was provided, we can guess it by concatenating the two
+		// models using underscores in alphabetical order. The two model names
+		// are transformed to snake case from their default CamelCase also.
+		if (is_null($collection))
+		{
+			$collection = snake_case(str_plural(class_basename($related)));
+		}
+
+		// Now we're ready to create a new query builder for the related model and
+		// the relationship instances for the relation. The relations will set
+		// appropriate query constraint and entirely manages the hydrations.
+		$query = $instance->newQuery();
+
+		return new BelongsToMany($query, $this, $collection, $foreignKey, $otherKey, $caller['function']);
+	}
+
     /**
      * Get a new query builder instance for the connection.
      *
@@ -274,4 +312,4 @@ public function __call($method, $parameters)
         return parent::__call($method, $parameters);
     }
 
-}
+}