javascript - Ajax 用于发布赞成票/反对票(停止页面刷新)

Question

我在我的 Rails 应用程序中使用“acts_as_votable”gem，以便用户可以对帖子进行投票。我正在尝试添加 Ajax 功能，以便在用户对帖子点赞时不必刷新整个页面。

我的赞成票/反对票链接可以点击并记录投票，但渲染没有刷新，票数仍然保持不变(我仍然需要刷新页面才能看到计数变化)。

我可以在运行日志中看到这个错误:

Rendered posts/downvote.js.erb (3.4ms)
Completed 500 Internal Server Error in 77ms (ActiveRecord: 8.4ms)

ActionView::Template::Error (undefined method `id' for nil:NilClass):
    1: $(document).ready(function(){
    2:     $('#vote_<%= p.id %>').html("<%= escape_javascript render :partial => 'vote' %>");
    3: });
  app/views/posts/downvote.js.erb:2:in `_app_views_posts_downvote_js_erb__811382410496335987_70314739481440'
  app/controllers/posts_controller.rb:44:in `downvote'


  Rendered /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-4.2.5/lib/action_dispatch/middleware/templates/rescues/_trace.text.erb (1.0ms)
  Rendered /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-4.2.5/lib/action_dispatch/middleware/templates/rescues/_request_and_response.text.erb (0.7ms)
  Rendered /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-4.2.5/lib/action_dispatch/middleware/templates/rescues/template_error.text.erb (17.0ms)

这是我的:

routes.rb

  resources :posts do 
    member do
      put "like", to: "posts#upvote"
      put "dislike", to: "posts#downvote"
    end
  end

posts_controller.rb

def upvote
  @post = Post.find(params[:id])
  @post.upvote_by current_user
    respond_to do |format|
        format.html { redirect_to :back }
        format.js 
    end
end

def downvote
  @post = Post.find(params[:id])
  @post.downvote_by current_user
    respond_to do |format|
        format.html { redirect_to :back }
        format.js 
    end
end

探索.html.erb (/views/pages/explore.html.erb)

<% if @posts.each do |p| %>
<div class="panel-body">
  <p class="post-content"><%= auto_link(p.content, :html => { :target => '_blank' }) %></p>

  <%= render :partial => '/posts/vote', :class => "vote", :locals => { p: p } %>

</div>
<% end %>

_vote.html.erb (/views/posts/_vote.html.erb)

<<div id="vote_<%= p.id %>" class="vote">
  <%= link_to 'Vote Up', like_post_path(p), :class => "upvote", :method => :put, :remote => true %>
  <span><%= p.score %></span>  <!--show the current vote-->
  <%= link_to 'Vote Down', dislike_post_path(p), :class => "downvote", :method => :put, :remote => true %>
</div>

upvote.js.erb (/views/posts/upvote.js.erb)

$(document).ready(function(){
    $('#vote_<%= p.id %>').html("<%= escape_javascript render :partial => 'vote' %>");
});

downvote.js.erb (/views/posts/downvote.js.erb)

$(document).ready(function(){
    $('#vote_<%= p.id %>').html("<%= escape_javascript render :partial => 'vote' %>");
});

是我的 javascript 有问题，还是我渲染的有问题？提前谢谢你。

Answer 1

1. _vote.html.erb (/views/posts/_vote.html.erb) 第一行的“<<”会出现语法错误.

2. 在您的 *.js.erb 文件中只有来自 Controller 操作的 @post，而不是您 View 中的 p。尝试如下更新:

upvote.js.erb (/views/posts/upvote.js.erb)

$(document).ready(function(){
  $('#vote_<%= @post.id %>').html("<%= escape_javascript render :partial => 'vote', locals: { p: @post } %>");
});

downvote.js.erb (/views/posts/downvote.js.erb)

$(document).ready(function(){
  $('#vote_<%= @post.id %>').html("<%= escape_javascript render :partial => 'vote', locals: { p: @post } %>");
});

希望对您有所帮助。 :)