Dynamically add fields in rails with out nested attributes

Question

I am in the early stages of creating an app, and am just putting some basic code in place. Here is the current code...

app/views/cards/front.html.erb

<%= form_for(front_of_card_path) do |f| %>
  <%= f.fields_for :competency_templates do |builder| %>
    <%= render 'add_fields', f: builder %>
  <% end %>
  <%= link_to_add_fields "Add New Tag", f, :skill %>
<% end %>

routes

 controller :cards do
    get  '/front',            action: 'front',  as: 'front_of_card'
    post '/save',             action: 'create', as: 'save_card'
    get  '/my_contact_info',  action: 'back',   as: 'back_of_card'
    put  '/save',             action: 'update', as: 'save_card'
    get  '/my_card',          action: 'show',   as: 'card'
  end

controller

  def create
    @skill= Skill.new(params[:skill])
    @tag = Tag.new(params[:tag])
    @tag.save
    @skill.tag_id = @tag.id
    @skill.save
    redirect_to front_of_card_path, notice: 'Skill was successfully created.'
    #get user/session
    #save skills & tags
  end

cards.js.coffee

jQuery ->
  $('form').on 'click', '.remove_fields', (event) ->
    $(this).prev('input[type=hidden]').val('1')
    $(this).closest('fieldset').hide()
    event.preventDefault()

  $('form').on 'click', '.add_fields', (event) ->
    time = new Date().getTime()
    regexp = new RegExp($(this).data('id'), 'g')
    $(this).before($(this).data('fields').replace(regexp, time))
    event.preventDefault()

app_helper

module ApplicationHelper
  def link_to_add_fields(name, f, association)
    new_object = f.object.send(association).klass.new
    id = new_object.object_id
    fields = f.fields_for(association, new_object, child_index: id) do |builder|
      render(association.to_s.singularize + "_fields", f: builder)
    end
    link_to(name, '#', class: "add_fields", data: {id: id, fields: fields.gsub("\n", "")})
  end
end

So right now this code gives me two text fields. One for the a tag name and another for a tag weight, and the controller inserts everything in the DB. I would like use some javascript to dynamically add as many of these tag/weight fields as I like. Everything I've found seems to focus on nested attributes. Any ideas appreciated.

Update

Added more code to flesh this out. The issue I am having is the 3rd variable I am passing in on this line...

  <%= link_to_add_fields "Add New Tag", f, :skill %>

It does not like ':skill', but I am not sure what I should be passing here.

Answer 1

So here is what I came up with...here are my two models...

class Skill < ActiveRecord::Base
  belongs_to :tag
  attr_accessible :tag_id, :weight
end

class Tag < ActiveRecord::Base
  has_many :skills
  attr_accessible :name
end

I'm calling a partial from app/views/skills/_form.html.erb and using a js tag to add new fields. Also note that I am re-rendering the partial, then hiding it in the last div tag.

  <div id="skillSet">
    <%= render partial: "skills_form" %>

  </div>
  <a href="javascript:;" id="addNewTag">Add New Tag</a>

  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

<div class="hide" id="new_skills_form">
  <%= render partial: "skills_form", locals: {skill: false} %>
</div>

The partial is pretty simple. All I am doing here is storing the values in an array...

<div class="skillsForm">
  <%= label_tag 'tag' %>
  <%= text_field_tag 'tags[]' %>
  <%= label_tag 'weight' %>
  <%= text_field_tag 'weights[]' %>
</div>

...here is the javascript...real straight forward, just say when #addNewTag is clicked, appeand #new_skills_form to #skillSet

$(document).ready(function(){
  $("#addNewTag").click(function(){
    $("#skillSet").append($("#new_skills_form").html());
  });
});

...and finally the controller action decontructs the arrays, and saves them...

def create
    @skill = Skill.new(params[:skill])
    tags = params[:tags]
    weights = params[:weights]

    tags.each_with_index do |tag, index|
      tag = Tag.create :name => tag
      Skill.create :tag_id => tag.id, :weight => weights[index]
    end
  end