Saving multiple records with a single form in Rails 4

Question

I have a model called Family, which belongs_to User I want to enable the user to add multiple family members in a single form, which is in

Answer 1

You need to tweak your code like this.Assuming you have the attribute name in users table.

In your User model

class User < ActiveRecord::Base
    has_many :families, :dependent => :destroy 
    accepts_nested_attributes_for :families, :allow_destroy => true
end

In your users_controller

def new
@user = User.new
@family = 3.times { @user.families.build } #here
end

Your strong parametrs should look like this

def user_params 
params.require(:user).permit(:name, families_attributes: [:name,:email]) 
end

#users/new.html.erb
<%= form_for(@user) do |f| %>
<div class="field">
<%= f.label :name %><br />
<%= f.text_field :name %>
</div>
<%= f.fields_for :familes do |builder| %>
<%= render 'family_fields', :f => builder %>
<% end %>
<div class="actions">
<%= f.submit %>
</div>
<% end %>

#users/_family_fields.html.erb
<div>
<%= f.label :name, "Name" %>        
<%= f.text_field :name %>
<br>
<%= f.label :email, "Email" %>
<%= f.text_field :email %>
</div>

Answer 2

You want to use nested forms. You should be able to copy and paste the following code to get going:

app/models/family.rb

class Family < ActiveRecord::Base
  has_many :users

  accepts_nested_attributes_for :users
end

app/models/user.rb

class User < ActiveRecord::Base
  belongs_to :family
end

app/views/families/new.html.erb

<%= form_for(@family) do |f| %>
  <%= f.fields_for :users do |user| %>
    <p>
    <%= user.text_field :name %><br>
    <%= user.text_field :email %>
    </p>
  <% end %>

  <%= f.submit %>
<% end %>

app/controllers/families_controller.rb

  [...]

  def new
    @family = Family.new
    3.times { @family.users.build }
  end

  [...]

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_family
      @family = Family.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def family_params
      params.require(:family).permit(:name, users_attributes: [ :name, :email ])
    end

Answer 3

The way that i always do this is to make a new action update_multiple. This expects params with the following structure (using your Family example, and updating two records, with ids 123 and 456)

params = {:families => {123 => {:name => "foo", :address => "bar"}, 456 => {:name => "baz", :address => "qux"} }}

and the action works like so:

@families = []
params[:families].each do |id, attributes|
  if family = Family.find_by_id(id)
    family.update_attributes(attributes)
    @families << family
  end
end

In order to set up the params with the required structure, your form would be set up like so:

<% @families.each do |family| %>
  <div class="family">
    <label>Name: <%= text_field_tag "families[#{family_id}][name]", family.name %></label>
    <label>Address: <%= text_field_tag "families[#{family_id}][address]", family.address %></label>
  </div>
<% end %>

You could, instead of making a new action, change the structure of your update action to do the standard code if it gets params[:family] and the above code if it gets params[:families].