nested form has many through rails4 - ruby-on-rails

Question

I'm not getting the expected results, the Skills are not getting saved. I want to allow each person to have say a primary skill ONLY 1.
DB
# Table name: people
#
# id :integer not null, primary key
# first_name :string(255)
# last_name :string(255)
# headline :string(255)
# description :string(255)
# user_id :integer
# created_at :datetime
# updated_at :datetime
#
# == Schema Information
#
# Table name: skills
#
# id :integer not null, primary key
# title :string(255)
# description :text
# created_at :datetime
# updated_at :datetime
#
# == Schema Information
#
# Table name: entity_skills
#
# id :integer not null, primary key
# skill_id :integer
# person_id :integer
# created_at :datetime
# updated_at :datetime
#
Models
class Person < ActiveRecord::Base
has_many :entity_skills
has_many :skills, through: :entity_skills, foreign_key: "person_id"
accepts_nested_attributes_for :skills
end
class Skill < ActiveRecord::Base
has_many :entity_skills
has_many :people, through: :entity_skills, foreign_key: "person_id"
end
class EntitySkill < ActiveRecord::Base
belongs_to :person
belongs_to :skill
end
Controller
def new
#person = Person.new
#all_skills = Skill.all
#entity_skills = #person.skills.build
end
def edit
#all_skills = Skill.all
#entity_skills = #person.entity_skills.build
end
def create
#person = Person.new(person_params)
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(:first_name, :last_name, :headline, :description, :user_id, :employer_id, skills_attributes: [:id])
end
Form
<%= form_for(#person) do |f| %>
....
....
<h2>Skills</h2>
<%= f.fields_for #entity_skills do |es| %>
<%= es.label "All Skills" %>
<%= collection_select(:skills, :id, #all_skills, :id, :title) %>
<% end %>
<div class="actions">
<%= f.submit %>
</div>
<% end %>
Nothing is being saved for the skills, Can someone explain what is going on?

Answer 1

DB
# == Schema Information
#
# Table name: entity_skills
#
# id :integer not null, primary key
# skill_id :integer
# person_id :integer
# created_at :datetime
# updated_at :datetime
# position :integer
#
Controller
def new
#person = Person.new
#all_skills = Skill.all
5.times {#person.entity_skills.build}
end
def create
#person = Person.new(person_params)
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(:first_name, :last_name, :headline, :description, :user_id, :employer_id, :entity_skills_attributes => [:skill_id, :position, :person_id, :id])
end
Form
<h2>Skills</h2>
<% i=0 %>
<%= f.fields_for :entity_skills do |builder| %>
<% i+=1 %>
<%= render 'shared/skills_fields', :f => builder, :i=> i %>
<% end %>
shared/skills_fields
<div class="field">
<%= f.label "All Skills" %>
<%= f.collection_select(:skill_id, Skill.all, :id, :title) %>
<%= f.hidden_field :position, :value=>i %>
<%= f.hidden_field :person_id, :value=>#person.id %>
</div>
I had a few things funky, params were accepted but not assigned correctly to the form, also made mistake of using :skills in the permitted params instead of :entity_skills_attributes => [:skill_id, :position]
To work with updates all I had to do was
def edit
#entity_skills= #person.entity_skills
end
I will use the position to reorder skills in case anyone wonders ;-)
Finally solved

Answer 2

You cant save a has_many through without constructing the join records.
Perhaps checkout this tutorial by Dave Shepard which runs through the things you need to do with a full example.