"Add comments" guide

_posts/2012-04-18-app.markdown

@@ -251,5 +251,5 @@ root :to => redirect("/ideas")
 
 ## Additional Guides
 
-* GUIDE 1: [Add commenting by Janika Liiv](http://janikaliiv.eu/homework/)
+* GUIDE 1: [Add commenting by Janika Liiv](/commenting)
 * GUIDE 2: [Put your app online with Heroku by Terence Lee](/heroku)

_posts/2012-04-30-commenting.markdown

@@ -0,0 +1,120 @@
+---
+layout: default
+title: Commenting functionality for the Rails Girls app
+permalink: commenting
+---
+# Commenting for Rails Girls App
+*Created by Janika Liiv, [@janikaliiv](https://twitter.com/janikaliiv)*
+
+We are going to add the possibility to comment ideas in your *railsgirls* application.
+
+The instructions for installing rails and building the ideas app can be found [here](/app)
+
+## Step 1: Add foreigner gem
+
+Add to Gemfile
+{% highlight ruby %}
+gem 'foreigner'
+{% endhighlight %}
+
+In your terminal stop the server if it's running and type
+{% highlight sh %}
+bundle install
+{% endhighlight %}
+
+## Step 2: Create comment scaffold
+
+Create comment scaffold, with the commentator name, the comment body (contents of the comment) and with the reference to the ideas table (idea_id). 
+{% highlight sh %}
+rails g scaffold comment user_name:string body:text idea_id:integer
+{% endhighlight %}
+
+## Step 3: Add foreign key connections
+Add to migration the foreing key  connection. Open db/migrate/ and the file, which name ends with 'create_comments.rb'. After
+{% highlight ruby %}
+t.timestamps
+end
+{% endhighlight %}
+
+add
+{% highlight ruby %}
+add_foreign_key :comments, :ideas
+{% endhighlight %}
+
+Now migrate the database changes by typing in your terminal
+{% highlight sh %}
+rake db:migrate
+{% endhighlight %}
+
+start your server with:
+{% highlight sh %}
+rails s
+{% endhighlight %}
+
+## Step 4: Add relations to models
+
+You need to make sure that Rails knows the connection between objects (ideas and comments). 
+As one idea can have many comments we need to make sure the idea model knows that. 
+Open app/models/idea.rb and after the row
+{% highlight ruby %}
+class Idea < ActiveRecord::Base
+{% endhighlight %}
+add
+{% highlight ruby %}
+has_many :comments
+{% endhighlight %}
+
+The comment also has to know that it belongs to an idea.So open app/models/comment.rb and after
+{% highlight ruby %}
+class Comment < ActiveRecord::Base
+{% endhighlight %}
+
+add the row
+{% highlight ruby %}
+belongs_to :idea
+{% endhighlight %}
+
+## Step 5: Render the comment form and existing comments
+
+Open app/views/ideas/show.html and after the image_tag
+{% highlight erb %}
+<%= image_tag(@idea.picture_url, :width => 600) if @idea.picture.present? %>
+{% endhighlight %}
+
+add
+{% highlight erb %}
+<h3>Comments</h3>
+<% @idea.comments.each do |comment| %>
+  <div>
+    <strong><%= comment.user_name %></strong>
+    <br />
+    <p><%= comment.body %><p>
+  </div>
+<% end %>
+<%= render 'comments/form' %>
+{% endhighlight %}
+
+In app/controllers/ideas_controller.rb add to show action after the row
+{% highlight ruby %}
+@idea = Idea.find(params[:id])
+{% endhighlight %}
+
+this
+{% highlight ruby %}
+@comment = @idea.comments.new
+{% endhighlight %}
+
+Open comments/_form.html and after
+{% highlight erb %}
+  <div class="field">
+    <%= f.label :body %><br />
+    <%= f.text_area :body %>
+  </div>
+{% endhighlight %}
+
+
+add the row
+{% highlight erb %}
+<%= f.hidden_field :idea_id %>
+{% endhighlight %}
+That's it. Now view an idea you have inserted to your application and there you should see the form for inserting a comment