Discuss about the dynamically generated accessor methods because of association.
There are 20 callbacks. 18 are before/after pairs, 2 are after_find and after_initialize
2 ways to define callback
1 :multipart - If set to true, the enctype is set to "multipart/form-data". 2 :method - The method to use when submitting the form, usually either "get" or "post". If "put", "delete", or another verb is used, a hidden input with name _method is added to simulate the verb over post. 3 A list of parameters to feed to the URL the form will be posted to.