Implementing ancestry on a nested resource throwing an error - ruby-on-rails

Question

I am implementing ancestry on a nested resource.
resources :loads do
resources :messages
end
Here is my index action
def index
load = Load.find(params[:load_id])
#messages = load.messages.scoped
#message = load.messages.new
end
My index.html.erb is throwing the following error.
Missing partial messages/message with {:locale=>[:en],
:formats=>[:html], :handlers=>[:erb, :builder, :coffee]}. Searched in:
* "C:/Sites/final/cloud/app/views"
My index.html.erb is as follow
<% title "Messages" %>
<%= nested_messages #messages.arrange(:order => :created_at) %>
<%= render "form" %>
Here is my nested_message definition
module MessagesHelper
def nested_messages(messages)
messages.map do |message, sub_messages|
render(message) + content_tag(:div, nested_messages(sub_messages), :class => "nested_messages")
end.join.html_safe
end
end
Here is my _message.html.erb
<div class="message">
<div class="created_at"><%= message.created_at.strftime("%B %d, %Y") %></div>
<div class="content">
<%= link_to message.content, message %>
</div>
<div class="actions">
<%= link_to "Reply", new_load_message_url(:parent_id => message) %> |
<%= link_to "Destroy", [message.load, message], :confirm => "Are you sure?", :method => :delete %>
</div>
</div>
Any help appreciated.

Answer 1

This error states that your application has tried to search for a partial _messages.html.erb, as a result of this the partial must not be in your /app/views/messages which results in the message you are being shown. Check your messages directory and check if you have this partial. Going by your nested resources I am guessing your association between Load and Message is:
class Load < ActiveRecord::Base
has_many :messages
end
class Message < ActiveRecord::Base
belongs_to :load
end
Further more I noticed that you have the following line in your index action: #message = load.messages.new surely this does not seem right. Because what your telling your application to do is when the controller recieves a response to render the index action it should also create message by doing #message = load.messages.new which is why it is trying to render the partial.
To clarify things a bit more for you. If in your application you had a link_to to create a new user. Upon clicking the new user it will do something like:
def new
#user = User.new
respond_to do |format|
format.html # new.html.erb
format.json { render json: #user }
end
end
And will render `app/views/users/new.html.erb which inside this will most probably have a
<%= form_for #user do |f| %>
<%= render :partial => 'form', :locals => { :f => f } %>
<% end %>
This will call your partial which in normal cases would be _form.html.erb. The create action of a particular controller will come into play when you attempt to save the partial. Usually a create block for a controller will look like this:
def create
#title = "Create a user"
#user = User.new(params[:user])
if #user.save
redirect_to usermanagement_path
flash[:success] = "Created successfully."
else
#title = "Create a user"
render 'new'
end
end
Here inside the create action when your _form.html.erb or _message.html.erb is submitted it will try to create a new user by passing in the user through the params. I do thoroughly believe that your issue may potentially well be:
1) Your missing your _message.html.erb
2) Also you are calling a .new inside your index action.
Hope this clears this up for you.