Question

In my tickets.js.coffee:

$.ajax '/comments/add',
  type: 'POST',
  dataType: 'html'
  success: ( data ) ->
    alert 'success'

<%= form_for @comment, :url => user_ticket_message_comments_path( @user, @ticket, m ), :html => { :class => "add-comment", :id => "add-comment-" + @ticket.id.to_s } do |f| %>
  <%= f.label :body, "Add comment" %>
  <%= f.text_area :body %>
  <%= f.hidden_field :message_id, :value => m.id %>
  <%= f.submit "Add comment" %>
<% end %>

Comments table:

id | message_id | body
----------------------

CommentsController:

def create
  @comment = params[:comment]
  @comment.save
end

My routes.rb:

resources :messages do
  resources :comments
end

I get this error:

undefined method `save' for {"body"=>"awef", "message_id"=>"15"}:ActiveSupport::HashWithIndifferentAccess

Comment belongs to a Message and Message has many comments.

Where should I look to fix this error?

Answer 1

params[:comment] is a Hash, not a Comment object, and thus can’t be “saved”. You need to create a new Comment object and assign each attribute to it, then save the Comment object:

def create
  @comment = Comment.new(params[:comment])
  @comment.save
end

Depending on how “new” your app is, config.active_record.whitelist_attributes may be set to true, in which case the above will give you a security error and you should read the Rails Guides on Mass-Assignment for more information about how to properly assign attributes (you should actually read it either way).