app/views/partido_steps/entidades_participadas.html.erb
<div class="container">
<h2 class="page-header">Entidades</h2>
<%= render :layout => 'form' do |f| %>
<div class="row">
<div class="col-md-4">
<div class="form-inline">
<div class="form-group">
<%= link_to_add_association f, :participacion_entidads, class: 'btn btn-success form-control', data: { 'association-insertion-method': 'append', 'association-insertion-node': '.nueva-entidad' } do %>
<i class="fa fa-plus"></i> Agregar entidad
<% end %>
</div>
</div>
</div>
</div>
<div class="row nueva-entidad"></div>
<div class="row">
<%= f.fields_for :participacion_entidads do |builder| %>
<%= render 'participacion_entidad_fields', :f => builder %>
<% end %>
</div>
<% end %>
</div>