Q:

Use form_for for non-attribute values

I have a form_for like so:
<%= form_for(@post) do |f| %>

I would like to submit a parameter that is not an attribute of the model
<%= f.text_field :label%>

I have a Label model (labels has_many :posts and posts has_many :labels) and in the create action of the posts_controller I want to create a new Label object based off the label text_field.  With the above text_field I get:
undefined method `label'for #<Object>

How can I go about achieving this? 
Thanks in advance! 

A:

If your attribute doesn't exist into database table, and still you want to use it, then you have specify that attribute into model by following way
attr_accessor :name, :email, :content

