Rails simple like button with AJAX jQuery

Question

I'm about to build a like machinery for my recipe class.

class LikesController
  def update
    @like = Like.find(params[:id])
  end

  def destroy
    @like = Like.find(params[:id])
    @recipe = Recipe.find(params[:id])
    @like.destroy
  end
end

def show
  @recipe = Recipe.find(params[:id])
end

recipes/show.html.erb

<div id="like_form">
  <% if like = current_user.likes.find_by_recipe_id(@recipe.id) %>
    <%= form_for like, :html => { :method => :delete },:remote => true do |f| %>
      <%= f.submit "Unlike" %>
    <% end %>
  <% else %>
    <%= form_for current_user.likes.create(:recipe_id => @recipe.id), :remote => true do |f| %>
      <%= f.hidden_field :recipe_id %>
      <%= f.hidden_field :user_id %>
      <%= f.submit "Like" %>
    <% end %>
  <% end %>

likes/destroy.js.erb

$("#like_form").html("<%= escape_javascript(render('recipes/like')) %>")

likes/update.js.erb

$("#like_form").html("<%= escape_javascript(render('recipes/unlike')) %>")

recipes/_unlike.html.erb

<%= form_for @like, :html => { :method => :delete },
                :remote => true do |f| %>
  <%= f.submit "Unlike" %>
<% end %>

recipes/_like.html.erb

<%= form_for current_user.likes.create(:recipe_id => @recipe.id), :remote => true do |f| %>
  <%= f.hidden_field :recipe_id %>
  <%= f.hidden_field :user_id %>
  <%= f.submit "Like" %>
<% end %>

After clicking on "Unlike", the "Like" button should be rendered. But I've no idea how to make the form_for argument in the _like.html partial.

I don't know how to get the value for recipe.id. How can I make recipe.id available in _like.html.erb?

ActionView::Template::Error (undefined method `id' for nil:NilClass):1:
<%= form_for current_user.likes.create(:recipe_id => @recipe.id), 
                              :remote => true do |f| %>
2:   <%= f.hidden_field :recipe_id %>
3:   <%= f.hidden_field :user_id %>
4:   <%= f.submit "Like" %>
  app/views/recipes/_like.html.erb:1:in
  _app_views_recipes__like_html_erb___1003281063_65806008'
  app/views/likes/destroy.js.erb:1:in
  _app_views_likes_destroy_js_erb___41116873_65874912'

Answer 1

fixed it with:

_like.html.erb

<% if like = current_user.likes.find_by_recipe_id(@recipe.id) %>
  <% else %>
    <%= form_for current_user.likes.build(:recipe_id => @recipe.id), :remote => true do |f| %>
    <%= f.hidden_field :recipe_id %>
    <%= f.hidden_field :user_id %>
    <%= f.submit "Like" %>
  <% end %>
<% end %>