CODEWITHSUNDEEP
ruby-on-railsrubyruby-on-rails-3
Joe Essey
Joe Essey

Reputation: 3527

Rails - How to iterate through associated objects?

I want to display a novel object and each of the illustrations associated with it on a web page. 1. I don't know how to properly write the code to get the associated illustrations of a novel. 2. I don't know how to properly reference an attribute of illustration objects. 3. I think my error may be from something unrelated.

Novel model:

Class Novel < ActiveRecord::Base
   has_many :illustrations
   attr_accessible :id, :name, :author, :edition, :publisher, :publication_city, :publication_date, :illustrations
   validates :id, uniqueness: true, presence: true
   validates :name, :author, :edition, :publisher, :publication_city, :publication_date,     presence: true
end

Illustration model:

class Illustration < ActiveRecord::Base
  belongs_to :novel
  attr_accessible :id, :illustrator, :image_url,
  :image_thumbnail_url, :name, :source, :tags,
  :description, :novel_id
  validates :id, uniqueness: true
  validates :name, :source, presence: true
  validates :image_url, 
  format: { with: %r{\.{gif|.jpg|.png}\Z}i, 
  message: 'must be a URL for .gif, .jpg, or .png'}
  validates :image_thumbnail_url, 
  format: { with: %r{\.{gif|.jpg|.png}\Z}i, 
  message: 'must be a URL for .gif, .jpg, or .png'}
  validates :illustrator, :tags, :description, presence: true
 end

Novel index class:

<% if notice %>
<p id="notice"><%= notice %></p>
<% end %>

<h1 style="padding-left:25px">Archive Overview</h1>

<% @novels.each do |novel| %>
<%= illustrations = novel.map(&:illustration) %>
<div class="row">
    <div class="span3" style="padding:0px 0px 25px 25px">
        <%= link_to novel.name, novel %>
    </div>
    <div class="span4">
        <p><%= novel.author%></p>
        <p><%= novel.publisher %></p>
        <p><%= novel.publication_date %></p>
    <div class="span5">
        <ul>    
            <% for illustrations.each do |illustration| %>
            <li><%= illustration.name %></li>
            <% end %>
        </ul>
    </div>
    </div>
</div>
<% end %>

The error I get with any combination of for loop syntax on illustrations.each:

SyntaxError in Booklist#index

Showing /home/joe/Documents/workspace/archive/app/views/booklist/index.html.erb where line #21 raised:

/home/joe/Documents/workspace/archive/app/views/booklist/index.html.erb:21: syntax error, unexpected '\n', expecting tCOLON2 or '[' or '.'
Extracted source (around line #21):

18:             <ul>    
19:                 <% for illustrations.each do |illustration| %>
20:                 <li><%= illustration.name %></li>
21:                 <% end %>
22:             </ul>
23:         </div>
24:         </div>
Trace of template inclusion: app/views/booklist/index.html.erb

Rails.root: /home/joe/Documents/workspace/archive

Upvotes: 0

Views: 685

Answers (1)

Ismael
Ismael

Reputation: 16730

You are mixing the syntax of for that is rarely with the each method. You should do it like this

<% illustrations.each do |illustration| %>
  <li><%= illustration.name %></li>
<% end %>

Upvotes: 2

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