Getting Started with Rails

comment.rb

class Comment < ActiveRecord::Base
  belongs_to :post
  attr_accessible :body, :commenter
end

post.rb

class Post < ActiveRecord::Base

  attr_accessible :content, :name, :title

	validates :name,  :presence => true
  validates :title, :presence => true,
                    :length => { :minimum => 5 }

  has_many :comments, :dependent => :destroy

  accepts_nested_attributes_for :tags, :allow_destroy => :true,
    :reject_if => proc { |attrs| attrs.all? { |k, v| v.blank? } }

end

posts__form.html.erb

<% @post.tags.build %>
<%= form_for(@post) do |post_form| %>
  <% if @post.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@post.errors.count, "error") %> prohibited this post from being saved:</h2>

      <ul>
      <% @post.errors.full_messages.each do |msg| %>
        <li><%= msg %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field">
    <%= post_form.label :name %><br />
    <%= post_form.text_field :name %>
  </div>
  <div class="field">
    <%= post_form.label :title %><br />
    <%= post_form.text_field :title %>
  </div>
  <div class="field">
    <%= post_form.label :content %><br />
    <%= post_form.text_area :content %>
  </div>
  <h2>Tags</h2>
  <%= render :partial => 'tags/form',
              :locals => { :form => post_form } %>
  <div class="actions">
    <%= post_form.submit %>
  </div>
<% end %>

posts_controller.rb

class PostsController < ApplicationController

  http_basic_authenticate_with :name => "vitor", :password => "123456", :except => [:index, :show]

  # GET /posts
  # GET /posts.json
  def index
    @posts = Post.all

    respond_to do |format|
      format.html # index.html.erb
      format.json { render json: @posts }
    end
  end

  # GET /posts/1
  # GET /posts/1.json
  def show
    @post = Post.find(params[:id])

    respond_to do |format|
      format.html # show.html.erb
      format.json { render json: @post }
    end
  end

  # GET /posts/new
  # GET /posts/new.json
  def new
    @post = Post.new

    respond_to do |format|
      format.html # new.html.erb
      format.json { render json: @post }
    end
  end

  # GET /posts/1/edit
  def edit
    @post = Post.find(params[:id])
  end

  # POST /posts
  # POST /posts.json
  def create
    @post = Post.new(params[:post])

    respond_to do |format|
      if @post.save
        format.html { redirect_to @post, notice: 'Post was successfully created.' }
        format.json { render json: @post, status: :created, location: @post }
      else
        format.html { render action: "new" }
        format.json { render json: @post.errors, status: :unprocessable_entity }
      end
    end
  end

  # PUT /posts/1
  # PUT /posts/1.json
  def update
    @post = Post.find(params[:id])

    respond_to do |format|
      if @post.update_attributes(params[:post])
        format.html { redirect_to @post, notice: 'Post was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: "edit" }
        format.json { render json: @post.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /posts/1
  # DELETE /posts/1.json
  def destroy
    @post = Post.find(params[:id])
    @post.destroy

    respond_to do |format|
      format.html { redirect_to posts_url }
      format.json { head :no_content }
    end
  end
end

posts_new.html.erb

<h1>New post</h1>

<%= render 'form' %>

<%= link_to 'Back', posts_path %>

tag.rb

class Tag < ActiveRecord::Base
  belongs_to :post
  attr_accessible :name
end

tags__form.html.erb

<%= form.fields_for :tags do |tag_form| %>
  <div class="field">
    <%= tag_form.label :name, 'Tag:' %>
    <%= tag_form.text_field :name %>
  </div>
  <% unless tag_form.object.nil? || tag_form.object.new_record? %>
    <div class="field">
      <%= tag_form.label :_destroy, 'Remove:' %>
      <%= tag_form.check_box :_destroy %>
    </div>
  <% end %>
<% end %>