################## model ###############

class Term < ActiveRecord::Base
 belongs_to :post
 belongs_to :category
end

class Post < ActiveRecord::Base
 belongs_to :user
 has_many :terms
 
 has_many :categories, :through => :terms
 
 has_many :comments

 def to_s
  title
 end
end

class Category < ActiveRecord::Base

 has_many :posts
 has_many :posts, :through => :terms

 def to_s
  title
 end

end

################## views ###############

########## categories/show ############# 

<h1>Category <em><%= @category %></em></h1>

<section class="listing">
 <%= render partial: 'posts/post', collection: @category.posts.order('created_at desc') %>
</section>

################## shema #######################

  create_table "categories", force: :true do |t|
    t.string   "title"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end

  create_table "comments", force: :true do |t|
    t.integer  "post_id"
    t.integer  "user_id"
    t.text     "comment"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end

  create_table "posts", force: :true do |t|
    t.string   "title"
    t.text     "content"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
    t.integer  "user_id"
  end

  create_table "terms", force: :true do |t|
    t.integer  "post_id"
    t.integer  "category_id"
    t.datetime "created_at",  null: false
    t.datetime "updated_at",  null: false
  end

  create_table "users", force: :true do |t|
    t.string   "email",                  default: "", null: false
    t.string   "encrypted_password",     default: "", null: false
    t.string   "reset_password_token"
    t.datetime "reset_password_sent_at"
    t.datetime "remember_created_at"
    t.integer  "sign_in_count",          default: 0,  null: false
    t.datetime "current_sign_in_at"
    t.datetime "last_sign_in_at"
    t.inet     "current_sign_in_ip"
    t.inet     "last_sign_in_ip"
    t.datetime "created_at",                          null: false
    t.datetime "updated_at",                          null: false
  end

  add_index "users", ["email"], name: "index_users_on_email", unique: true, using: :btree
  add_index "users", ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true, using: :btree