5步实现网站点赞功能

Step 1.安装 gem

Gemfile

+ gem 'acts_as_votable', '~> 0.10.0'

执行bundle install

执行rails g acts_as_votable:migration

然后rake db:migrate

Step 2.以购物网站为例：修改 product.rb

app/models/product.rb 

+ acts_as_votable

Step 3.修改 routes.rb

config/routes.rb

  resources :products do
    member do
      post :add_to_cart
      put "like", to: "products#upvote"
    end
  end

Step 4.修改 app/controller/products_controller.rb

app/controllers/products_controller.rb

  before_action :authenticate_user!, only: [:upvote, :downvote]
  ...

  def upvote
    @product = Product.find(params[:id])
    @product.upvote_by current_user
    redirect_to :back
  end

  def downvote
    @product=Product.find(params[:id])
    @product.downvote_by current_user
    redirect_to :back
  end

  ...

Step 5.修改html.erb 文件

#在需要添加点赞功能的页面加入如下内容：
<%= link_to like_product_path(product), method: :put do %>
    <div class="pi-thumbs-up">
        赞（<%= product.get_upvotes.size %>）
    </div>
<% end %>

#在需要添加差评功能的页面加入如下内容：
<%= link_to dislike_product_path(product), method: :put do %>
<div class="pi-thumbs-down">
    踩（<%=product.get_downvotes.size%>）
</div>
#注意：路径的参数是选择@product 还是 product 要根据具体的页面来确定。