Embedded Document not being added - ruby-on-rails-3

Question

Having trouble adding an embedded document. I am trying to add a tag which is embedded in the user.
user.rb
class User
include Mongoid::Document
field :name
validates_presence_of :name
validates_uniqueness_of :name, :email, :case_sensitive => false
attr_accessible :name, :email, :password, :password_confirmation
embeds_many :tags
embeds_many :tasks
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable
end
tag.rb
class Tag
include Mongoid::Document
field :name
embedded_in :user, :inverse_of => :tags
references_many :tasks
end
tags_controller.rb
def create
##user = User.find(:first, :conditions => {:_id => "4d3ae09bf5c4930b2b000004"} )
#user = current_user
#tag = Tag.new(params[:tag])
#user.tags << #tag
#tag.save
redirect_to #tag, :notice => "Tag created!"
end
This is the output to the server when I try to create a new tag.
Started POST "/tags" for 127.0.0.1 at 2011-02-18 13:46:03 -0500
Processing by TagsController#create as HTML Parameters: {"utf8"=>"✓", "authenticity_token"=>"6p+Jova7Hol2v5LRReSp2fhNJ967EwkeIzAWyrChQRE=", "tag"=>{"name"=>"general"}, "commit"=>"Create Tag"}
db['users'].find({:_id=>BSON::ObjectId('4d39cd63f5c4930708000001')}, {}).limit(-1) MONGODB
db['users'].update({"_id"=>BSON::ObjectId('4d39cd63f5c4930708000001')}, {"$push"=>{"tags"=>{"name"=>"general", "_id"=>BSON::ObjectId('4d5ebe6bf5c493554d000002')}}}) Redirected to
http://localhost:3000/tags/4d5ebe6bf5c493554d000002 Completed 302 Found in 5ms
Not really sure what the issue is or where to start. It actually looks like the user is found then an update is being made to tags but it is not successful.
Thanks

Answer 1

The Tags class in your model is embedded inside of user (via the embeds_many association), rather than a table on its own. So following the updates in your controller, you should have something like this:
> db.users.find()
{
_id: ObjectId('4d39cd63f5c4930708000001'),
tags: [
{
_id: ObjectId('4d5ebe6bf5c493554d000002'),
name: "General"
}
]
}
Using MongoID, you can also have Tags appear in their own collection by replacing "embeds_many" with "references_many".
In the comments above, you'll see that the issue berek-bryan was having had to do with where the tag was being added. He expected the tag to be added in its own collection, hence the question. Actually, the tags were being added right into his users collection.