Nested Forms in Rails 4.0.3 - ruby-on-rails

Question

Im struggling with a nested form in Rails 4, this is the first time that I made a form of that kind. I have read lots of documentation but Im not able to make it work. :-(
I have two models: Person and Disease. One person can have many diseases and one disease belongs to person. Looks quite simple. The form for Diseases is not saved in the database.
Person Model:
class Person < ActiveRecord::Base
belongs_to :user
has_many :diseases, :dependent => :destroy #if you delete a person you also delete all diseases related
has_many :appointments, :dependent => :destroy
validates_presence_of :name, :email
validates :name, :length => {:maximum => 50, :too_long => "name is too long"}
VALID_EMAIL_REGEX = /\A[\w+\-.]+#[a-z\d\-.]+\.[a-z]+\z/i
validates :email, format: { :with => VALID_EMAIL_REGEX , message: "is invalid" }
accepts_nested_attributes_for :diseases
end
Disease Model:
class Disease < ActiveRecord::Base
belongs_to :person
has_many :treatments
validates_presence_of :name, :start
validates :name, :length => {:maximum => 50, :too_long => "is too long, you can use the description field"}
validate :start_must_be_before_end, :unless => [:chronical, :unfinished], :presence => true
validates :end, :presence => true, :unless => [:chronical, :unfinished], :presence => true
validates :description, :length => {:maximum => 5000, :too_long => "is too long"}
def start_must_be_before_end
if self[:end] < self[:start]
errors.add(:start, "must be before end time")
return false
else
return true
end
end
end
People Controller:
def create
current_user
#person = Person.new(person_params)
#person.user_id = #current_user.id
respond_to do |format|
if #person.save
format.html { redirect_to #person, notice: 'Person was successfully created.' }
format.json { render action: 'show', status: :created, location: #person }
else
format.html { render action: 'new' }
format.json { render json: #person.errors, status: :unprocessable_entity }
end
end
end
def person_params
params.require(:person).permit(:name, :surname, :gender, :birthdate, :bloodtype, :user_id, :phone, :email, diseases_attributes: [:id, :description] )
end
Form:
<%= simple_form_for #person do |f| %>
<%= f.input :name %>
<%= f.input :email %>
<%= simple_fields_for :diseases do |my_disease| %>
<%= my_disease.input :description %>
<% end %>
<%= f.button :submit %>
<% end %>
Thanks a lot for your help.

Answer 1

The issue is with line <%= simple_fields_for :diseases do |my_disease| %>.It should be
<%= f.simple_fields_for :diseases do |my_disease| %>
This should work.
<%= simple_form_for #person do |f| %>
<%= f.input :name %>
<%= f.input :email %>
<%= f.simple_fields_for :diseases do |my_disease| %> #here
<%= my_disease.input :description %>
<% end %>
<%= f.button :submit %>
<% end %>
For more Info,see this API