Rails4：像按钮不能正常工作（像限制）

Question

我有一个帖子的喜欢/不喜欢按钮的问题。

什么我想要做的：

用户有很多帖子，每个用户只能按1喜欢或不喜欢（取消等）平均每个职位。我怎样才能做到这一点？

我的问题：

我可以按按钮一样，它显示计数1等，但是不喜欢按钮不起作用（无法取消等）。此外，职位的限制是不正常工作，我可以按2或3喜欢一个职位（同一职位）。

补充说明：

所有职位由最热门的职位（喜欢的号码）排序，它应是受欢迎的页面。所以我有流行的行动来排序最受欢迎的职位的帖子。

def popular 
    @posts = Post.joins(:likes).group(:id).order("count(*) 
    desc").paginate(:page => params[:page], :per_page => 18) 
    end 

喜欢表的列：

USER_ID，POST_ID，created_at，的updated_at

职位表中的列：

ID，标题，内容，USER_ID，created_at，的updated_at，图片，category_id，经度，纬度，地址

发展：sqlite3的生产：在PostgreSQL

post.rb

class Post < ActiveRecord::Base 

    belongs_to :user 
    belongs_to :category 
    validates :user_id, presence: true 
    validates :title, presence: true 
    validates :content, presence: true 
    validates :category_id, presence: true 
    has_many :likes, dependent: :destroy 
    has_many :post_attachments 
    attr_accessor :post_attachment_attributes 
    acts_as_commontable 
    geocoded_by :address 
    after_validation :geocode 
    accepts_nested_attributes_for :post_attachments,allow_destroy:true, reject_if: :all_blank 

    end 

like.rb

class Like < ActiveRecord::Base 
    belongs_to :post 
    belongs_to :user 
    end 

likes_controller.rb

class LikesController < ApplicationController 

    def like 
    @post = Post.find(params[:post_id]) 
    like = current_user.likes.build(post_id: @post.id) 
    like.save 
    end 

    def unlike 
    @post = Post.find(params[:post_id]) 
    like = current_user.likes.find_by(post_id: @post.id) 
    like.destroy 
    end 
    end 

_like_links.html.erb

<% if user_signed_in? %> 
    <% if current_user.likes.find_by(post_id: post.id) %> 
     <%= link_to (content_tag(:i, '', class: 'fa faheart')),unlike_path(post.id), method: :delete, remote: true %> 
     <%= post.likes.count %> Like 
    <% else %> 
    <%= link_to (content_tag(:i, '', class: 'fa fa-heart o')),like_path(post.id), method: :post, remote: true %> 
    <%= post.likes.count %> Like 
    <% end %> 
    <% else %> 
    <%= post.likes.count %> Like 
    <% end %> 

like.js.erb/unlike.js.erb

$('#like-link<%= @post.id %>').html('<%=escape_javascript(render("likes/like_links", post: @post)) %>'); 

任何帮助将是并欣赏。谢谢你的帮助！！

更改后喜欢控制器

Started POST "/like/25" for ::1 at 2017-05-11 17:29:17 +0900 
    Processing by LikesController#like as JS 
    Parameters: {"post_id"=>"25"} 
    User Load (0.3ms) SELECT "users".* FROM "users" WHERE 
    "users"."id" = ? ORDER BY "users"."id" ASC LIMIT 1 [["id", 1]] 
    Like Load (0.2ms) SELECT "likes".* FROM "likes" WHERE 
    "likes"."user_id" = ? AND "likes"."post_id" = ? LIMIT 1 
    [["user_id", 1], ["post_id", 25]] 
    (0.1ms) begin transaction 
    SQL (0.4ms) INSERT INTO "likes" ("user_id", "post_id", 
    "created_at", "updated_at") VALUES (?, ?, ?, ?) [["user_id", 1], 
    ["post_id", 25], ["created_at", "2017-05-11 08:29:18.009414"], 
    ["updated_at", "2017-05-11 08:29:18.009414"]] 
    (1.9ms) commit transaction 
    Rendered likes/like.js.erb (35.7ms) 
    Completed 500 Internal Server Error in 233ms (ActiveRecord: 17.4ms) 
    NoMethodError (undefined method `id' for nil:NilClass): 
    app/views/likes/like.js.erb:1:in 
    `_app_views_likes_like_js_erb___3930955212291711879_70111836109880' 

的index.html。ERB

<% @posts.each do |post| %> 
<div class="mdl-cell mdl-cell--6-col"> 
    <div class="demo-card-square mdl-card mdl-shadow--2dp"> 
    <div class="category category"><%= link_to post.category.name [post.category.name] %> 
    </div> 
    <div class="mdl-card__title mdl-card--expand" style="background: url('<%= post.post_attachments.first.picture %>') bottom center no-repeat #fff;"> 
    <h2 class="mdl-card__title-text"><%= post.title %></h2> 
    </div> 
    <div class="mdl-card__supporting-text"> 
    <%= post.content.truncate(120, separator: '.')%> 
    </div> 
    <div class="mdl-card__actions mdl-card--border"> 
    <a href="<%= post_path(post.id) %>" class="mdl-button mdl-button--colored mdl-js-button mdl-js-ripple-effect" data-upgraded=",MaterialButton,MaterialRipple"> 
     View more 
     <span class="mdl-button__ripple-container"><span class="mdl-ripple"></span></span></a> 
    <span id="like-link<%= post.id %>" class="like_box"> 
     <%= render "likes/like_links", post: post %> 
     </span> 
    </div> 
    </div> 
</div> 
<% end %> 

Answer 1

限制多喜欢：

class LikesController < ApplicationController 
    def like 
    current_user.likes.where(post_id: params[:post_id]).first_or_create 
    end 

    def unlike 
    if (like = current_user.likes.find_by_post_id(params[:post_id])).present? 
     like.destroy 
    end 
    end 
end 

代码重构的一点点：

<% if (user = current_user).present? %> 
    if user.likes.find_by(post_id: post.id) %> 
    <%= link_to (content_tag(:i, '', class: 'fa faheart')),unlike_path(post.id), method: :delete, remote: true %> 
    <% else %> 
    <%= link_to (content_tag(:i, '', class: 'fa fa-heart o')),like_path(post.id), method: :post, remote: true %> 
    <% end %> 
<% end %> 
<%= post.likes.count %> Like