为网站增加收藏功能

Step 1.建立收藏的 model

执行rails g model favorite

db/migrate/20170614122223_create_favorites.rb
class CreateFavorites < ActiveRecord::Migration[5.0]

  def change
    create_table :favorites do |t|
      t.integer :product_id
      t.integer :user_id
      t.timestamps
    end
  end
end

Step 2.建立关联

app/models/favorite.rb

class Favorite < ApplicationRecord
  belongs_to :user
  belongs_to :product
end

app/models/product.rb
 -  has_many :reviews
 +  has_many :reviews, dependent: :destroy
 +  has_many :favorites
 +  has_many :fans, :through => :favorites, :source => :user

    acts_as_votable

app/models/user.rb

   has_many :orders
 -  has_many :reviews
 +  has_many :reviews, dependent: :destroy
 +  has_many :favorites
 +  has_many :favorite_products, :through => :favorites, :source => :product

 +  def is_fan_of?(group)
 +    favorite_products.include?(group)
 +  end

Step 3.建立收藏的 controller

执行rails g controller favorites并修改

app/controllers/favorites_controller.rb

class FavoritesController < ApplicationController
  def index
    @products = current_user.favorite_products
  end
end

app/controllers/products_controller.rb 

def favorite
    @product = Product.find(params[:id])
    current_user.favorite_products << @product
    flash[:notice] = "您已收藏宝贝"
    redirect_to :back
  end

  def unfavorite
    @product = Product.find(params[:id])
    current_user.favorite_products.delete(@product)
    flash[:notice] = "您已取消收藏宝贝"
    redirect_to :back
  end

Step 4.增加相应的路由

config/routes.rb

+  resources :favorites
  resources :products do
    member do
      post :add_to_cart
+     post :favorite
+     post :unfavorite
      put "like", to: "products#upvote"
      put "dislike", to: "products#downvote"

    end

    resources :reviews

  end

Step 5.修改app/views/product/show.html.erb

app/views/products/show.html.erb

<div class="col-md-2"  >
          <% if current_user %>
           <% if !current_user.is_fan_of?(@product) %>
             <%= link_to favorite_product_path(@product), :class => "like btn btn-default", method: :post do %>
               <i class="fa fa-heart fa-lg"></i>
             <% end %>
           <% else %>
             <%= link_to unfavorite_product_path(@product), :class => "unlike btn btn-default", method: :post do %>
               <i class="fa fa-heart fa-lg"></i>
             <% end %>
           <% end %>
         <% else %>
           <%= link_to favorite_product_path(@product), :class => "like btn btn-default",method: :post do %>
             <i class="fa fa-heart fa-lg"></i>
           <% end %>
        <% end %>
        </div>
      </div>
      <div class="row share">
       <hr />
        <div class="col-md-6">
            <p> 收藏人气（<%= @product.fans.count %>） </p>
        </div>
        <div class="col-md-6">
          <%= link_to like_product_path(@product), method: :put do %>
            <div class="pi-thumbs-up">
              点赞（<%= @product.get_upvotes.size %>）
            </div>
          <% end %>
        </div>
      </div>

Step 6.建立收藏的 view

执行touch app/views/favorites/index.html.erb

app/views/favorites/index.html.erb

<% @products.each do |product|%>
  <p><%= link_to(product.title, product_path(product)) %></p>
  <p><%= product.description %></p>
  <p><%= product.price %></p>
<% end %>

完成！