Rails, Cocoon, Nested form not saving correctly - ruby-on-rails

Question

Hi I have a nested form with rails and cocoon. I tested everything for hours and tried all suggestions in related topics but nothing worked. Here is my setup:
student.rb (Studen Model)
has_many :parents, dependent: :destroy
accepts_nested_attributes_for :parents,
reject_if: proc { |attributes|
attributes['first_name'].blank? },
:allow_destroy => true
students/new.html.erb
<div class="content <% if !#active_tab %> active <% end %>" id="tabStudent">
<%= form_for #student, validate: true do |student| %>
<%= render 'student_fields', model: student %>
<%= hidden_field(:active, 'tab', value: #active_tab) %>
</div>
<div class="content <% if #active_tab === 'tabParents' %> active <% end %>" id="tabParents">
<h2>Parents</h2>
<div id="parents">
<%= student.fields_for :parents do |parent| %>
<%= render partial: 'parent_fields', locals: {include_mode: 'new', f: parent, added_by: ''} %>
<% end %>
<%= link_to_add_association 'add', student, :parents,
render_options: { locals: {include_mode: 'new', added_by: 'rails'}},
'data-association-insertion-node' => '#parents',
'data-association-insertion-method' => 'append' %>
</div>
</div>
students_controller.rb
def create
#student = Student.new(student_params)
#student.parents.build
if #student.save
flash[:success] = "Success"
redirect_to #student
else
render 'new'
end
end
private
def student_params
params.require(:student).permit(:first_name, :last_name, :gender,
parents_attributes: [:id, :first_name, :last_name, :gender, :_destroy])
end
students/_parent_fields.html.erb
<div class="nested-fields">
<div class="row links">
<div class="large-12 columns right">
<%= link_to_remove_association raw('<i style="color:#ff0000;" class="fi-x-circle"></i>'), f %>
</div>
</div>
<div class="row">
<fieldset>
<legend>Data</legend>
<div class="row">
<div class="large-3 columns field">
<%= f.label :gender, 'Student Gender' %>
<%= f.select(:gender, [['male', 'm'], ['female', 'f']]) %>
</div>
<div class="large-3 columns field">
<%= f.label :first_name, 'First Name' %>
<%= f.text_field :first_name %>
</div>
<div class="large-3 columns field">
<%= f.label :last_name, 'Last Name' %>
<%= f.text_field :last_name %>
</div>
</fieldset>
</div>
</div>
It works so far that I can add and remove the form fields but when I send it, only the first parent is saved to the database. If I add a second parent with the "add" link an empty record is saved to the db. The second form also doesn't show up in the post data so it's no surprise that the record is empty but I just can't figure out why the data is not transmitted correctly.
EDIT: I located the problem. I use curb-foundation for the css styling and for the nested form I use their "tabs":
<div class="tabs-content">
<div class="content <% if !#active_tab %> active <% end %>" id="tabStudent">
<%= form_for #student, validate: true do |student| %>
<%= render 'student_fields', model: student %>
<%= hidden_field(:active, 'tab', value: #active_tab) %>
</div>
<div class="content <% if #active_tab === 'tabParents' %> active <% end %>" id="tabParents">
<h2>Parents</h2>
<div id="parents">
<%= student.fields_for :parents do |parent| %>
<%= render partial: 'parent_fields', locals: {include_mode: 'new', f: parent, added_by: ''} %>
<% end %>
<%= link_to_add_association 'new', student, :parents,
render_options: { locals: {include_mode: 'new', added_by: 'rails'}},
'data-association-insertion-node' => '#parents',
'data-association-insertion-method' => 'append' %>
</div>
</div>
The nested divs seem to break cocoon's function. If I remove the divs it works. Does anybody still know how I can work out a solution that allows me to use tabs?

Answer 1

Riddle solved. The empty record was produced because of the #student.parents.build. Cocoon does not require this command.
The main problem was solved by moving the #form_for part out of the first foundation tab one layer up so it would show up above every tab. Then I wrote a little query function to only present it to the user in the first tab.