Question

Can anyone shed light on this for me?

undefined method `first_name’ for #

Here is the show.html

<p id="notice"><%= notice %></p>
<div id="container">
<p>
  <b>First name:</b>
  <%= @artist.firstname %>
</p>

<p>
  <b>Second name:</b>
  <%= @artist.surname %>
</p>

<p>
  <b>About:</b>
  <%= @artist.about %>
</p>
<div id="comments">

  <h2>Comments</h2>

<%= render :partial => "shared/comment", :collection => @artist.comments%>

</div
</div>

<%= render :partial => "image", :collection => @artist.images %>
<%= link_to 'Edit', edit_artist_path(@artist) %> |
<%= link_to 'Back', artists_path %>
<%= link_to 'show', images_path %>

Here is the partial

 <div class="comment">



     <p>


      <span class="commentator"><%= comment.commentator.display_name %> 

    say's</span>


      <%= comment.comment %>


      </p>



    </div

Here is the friend view

class Friends < ActiveRecord::Base
    attr_accessible :firstname, :surname
    has_many :comments, :as => :commentator, :class_name =>"Commentable"
    def display_name
    "#{self.firstname} #{self.surname}"
    end


end

This is the friends controller

class FriendsController < ApplicationController
  # GET /friends
  # GET /friends.xml
  def index
    @friends = Friend.all

    respond_to do |format|
      format.html # index.html.erb
      format.xml  { render :xml => @friends }
    end
  end

  # GET /friends/1
  # GET /friends/1.xml
  def show
    @friend = Friend.find(params[:id])

    respond_to do |format|
      format.html # show.html.erb
      format.xml  { render :xml => @friend }
    end
  end

  # GET /friends/new
  # GET /friends/new.xml
  def new
    @friend = Friend.new

    respond_to do |format|
      format.html # new.html.erb
      format.xml  { render :xml => @friend }
    end
  end

  # GET /friends/1/edit
  def edit
    @friend = Friend.find(params[:id])
  end

  # POST /friends
  # POST /friends.xml
  def create
    @friend = Friend.new(params[:friend])

    respond_to do |format|
      if @friend.save
        format.html { redirect_to(@friend, :notice => 'Friend was successfully created.') }
        format.xml  { render :xml => @friend, :status => :created, :location => @friend }
      else
        format.html { render :action => "new" }
        format.xml  { render :xml => @friend.errors, :status => :unprocessable_entity }
      end
    end
  end

  # PUT /friends/1
  # PUT /friends/1.xml
  def update
    @friend = Friend.find(params[:id])

    respond_to do |format|
      if @friend.update_attributes(params[:friend])
        format.html { redirect_to(@friend, :notice => 'Friend was successfully updated.') }
        format.xml  { head :ok }
      else
        format.html { render :action => "edit" }
        format.xml  { render :xml => @friend.errors, :status => :unprocessable_entity }
      end
    end
  end

  # DELETE /friends/1
  # DELETE /friends/1.xml
  def destroy
    @friend = Friend.find(params[:id])
    @friend.destroy

    respond_to do |format|
      format.html { redirect_to(friends_url) }
      format.xml  { head :ok }
    end
  end
end

I am trying to make it so a friend can leave a comment on an artists page but I keep getting the above error.

I am very new to Ruby so I apologise if I have left anything out.

Answer 1

Basically, rails will look at the database to figure out what fields are on a model. So make sure your migrations have been run, and that first_name exists on the db table.

Also, Friends is plural. In rails, your table is plural (friends), your model is singular (Friend), and your controller is plural (FriendsController). It is best not to go against this convention. Try renaming the model and see what happens