jQuery template solution for nested forms in rails

_form.html.erb

<!-- app/views/project_roles/_form.html.erb -->

<div class="projectRole">
  <%= form.label :name %>
  <%= form.text_field :name %>
  <!-- etc etc etc -->

  <!-- the JS down below relies on the following two lines being next to each other -->
  <%= form.hidden_field '_destroy' unless form.object.new_record? %>
  <a href="#" class="removeNestedItem">Delete</a>
</div>

_template.html.erb

<!-- app/views/project_roles/_template.html.erb -->

<script type="text/x-jquery-tmpl">
  <%= render :partial => '/project_roles/form', :locals => {:form => form} %>
</script>

application.js

$(document).ready(function() {
  $('.addNestedItem').click(function() {
    var template = $(this).prevAll('script[type=text/x-jquery-tmpl]:first').tmpl({index: new Date().getTime()});
    $(this).before(template);
    return false;
  });

  $('.removeNestedItem').live('click', function() {
    var hiddenField = $(this).prev('input[type=hidden]');
    if (hiddenField.length != 0)
      hiddenField.val('1').appendTo($(this).closest('form'));
    $(this).closest('div').remove();
    return false;
  });
});

edit.html.erb

<!-- app/views/projects/edit.html.erb -->

<% form_for @project do |f| -%>
  <% form.fields_for :project_roles, ProjectRole.new, :child_index => '${index}' do |tmpl_form| %>
    <%= render :partial => '/project_roles/template', :locals => {:form => tmpl_form} %>
  <% end %>

  <div id="projectRoles">
    <% form.fields_for :project_roles do |pr_form| %>
      <%= render :partial => '/project_roles/form', :locals => {:form => pr_form} %>
    <% end %>
  </div>

  <a href="#" class="addNestedItem" rel="#tmplProjectRole">Add a Project Role</a>

<% end %>

project.rb

class Project < ActiveRecord::Base
    has_many :project_roles
    accepts_nested_attributes_for :project_roles, :allow_destroy => true
end

project_role.rb

class ProjectRole < ActiveRecord::Base
  belongs_to :project
end

In your edit.html.erb on lines 4 and 8 should it be f.fields_for instead of form.fields_for?

In your edit.html.erb on lines 4 and 8 should it be f.fields_for instead of form.fields_for?

@tekHudson maybe! Honestly this is from so long ago, and probably relies on whatever conventions existed for Rails 3 or whichever version of Rails existed 9 years ago when I originally wrote this. If f.fields_for works in your version of Rails, then yes! I've moved away from this type of server-rendered client-side code myself, for better or for worse. Best of luck! Sorry I couldn't be more sure of my answer.