如何使平均评等显示在每个对象的索引页中

Question

我有一个Rails应用程序，应该是帮助审查医院。到目前为止，我遵循了一个紧密的教程来构建，并且有一个相当可行的应用程序。

我正在尝试给这个应用程序添加一些新的功能。

1. 我希望用户能在首页的数据库中看到一份医院列表，清楚地显示医院的名称、形象和平均评价。

我可以成功地显示医院，图像和电话号码的索引/家庭pag，但努力显示平均评分的所有每家医院。这是奇怪的，因为我有完全相同的结构，在个别医院显示页，它在那里工作良好。

我觉得我离这里只有几步之遥，需要帮助。请参阅下面的代码片段：

index.html.erb

<div class="jumboFluid">
  <div class="jumbotron">
    <section class="content">
      <%= form_tag search_hospitals_path, method: :get, class: "form-group" do %>
        <div class="input-group">
          <div class="input-group-addon">Search</div>
            <p>
              <%= text_field_tag :search, params[:search],  class: "form-control formInput", placeholder: "Eye, Maternity" %>
              <%# <%= submit_tag "Search", name: nil, class: "btn btn-default" %>
            </p>
          </div>
        </div> 
      <% end %>
    </section>
  </div>
</div>
<div class="hospitalList">
  <h1 id="hospitalBanner">Hospitals</h1>
  <blockquote> 
    <p class="text-center"><cite>&#8220;Explore the best of healthcare available in your community&#8221;</cite> </p>
  </blockquote>

  <% content_for(:body_attributes) do %>
    data-no-turbolink="false"
  <% end %>

  <div class="container-fluid">
    <div class="row">
      <% @hospitals.each do |hospital| %>
        <div class="col-md-3">
          <div class="thumbnail">
            <%= link_to image_tag(hospital.image), hospital %>
            <div class="caption">
              <p> <%= link_to hospital.name, hospital %></p>
              <p> <%= hospital.phone %></p>
            </div>
          </div>
        </div>
      <% end %>
    </div>

    <br>

    <% if user_signed_in? && current_user.admin? %>
      <%= link_to 'New Hospital', new_hospital_path, class: "btn btn-link" %>
    <% end %>

<script>
  $('.star-rating').raty({
    path: 'https://s3-us-west-2.amazonaws.com/morafamedapp/stars',
    readOnly: true,
    score: function() {
      return $(this).attr('data-score');
    }
  });
</script>

</div>

工作显示代码

show.html.erb

<div class="row">
  <div class="col-md-3">
    <%= image_tag @hospital.image_url unless @hospital.image.blank? %>

    <h3>
      <%= @hospital.name %>
    </h3>

    <div class="star-rating" data-score= <%= @avg_rating %> ></div>
    <p><%= "#{@reviews.length} reviews" %></p>
    <%= social_share_button_tag("Share") %>


    <p>
      <strong>Address:</strong>
      <%= @hospital.address %>
    </p>

    <p>
      <strong>Phone:</strong>
      <%= @hospital.phone %>
    </p>

    <p>
      <strong>Website:</strong>
      <%= link_to @hospital.website, @hospital.website, target: :_blank %>
    </p>

    <%= link_to "Write a Review", new_hospital_review_path(@hospital), class: "btn btn-primary" %>

    <br>
    <br>

    <iframe width="230" height="230" frameborder="0" style="border:0"
  src="https://www.google.com/maps/embed/v1/place?q=<%= @hospital.address.parameterize %>&key=AIzaSyAc4mTzAGIA_8JFXAcL3XTBi-tzuxQCsBc" allowfullscreen></iframe>
  </div>

  <div class="col-md-9">
    <% if @reviews.blank? %>
      <h3>No reviews yet. Be the first to write one!</h3>
    <% else %>
      <table class="table">
        <thead>
          <tr>
            <th class="col-md-3"></th>
            <th class="col-md-9"></th>
          </tr>
        </thead>

        <tbody>
          <% @reviews.each do |review| %>
            <tr>
              <td>
                <h4>
                  <%= "#{review.user.first_name.capitalize} #{review.user.last_name.capitalize[0]}." %>
                </h4>
                <p><%= review.created_at.strftime("%-d/%-m/%y") %></p>
              </td>

              <td>
                <div class="star-rating" data-score= <%= review.rating %> ></div>
                <p><%= h(review.comment).gsub(/\n/, '<br/>').html_safe %></p>
                <%= social_share_button_tag("Share") %>

                <% if user_signed_in? %>
                  <% if (review.user == current_user) || (current_user.admin?) %>
                  <%= link_to "Edit", edit_hospital_review_path(@hospital, review) %>
                  <%= link_to "Delete", hospital_review_path(@hospital, review), method: :delete %>

                <% end %>
              <% end %>
              </td>
            </tr>
          <% end %>
        </tbody>
      </table>
    <% end %>
  </div>
</div>

<%= link_to 'Edit', edit_hospital_path(@hospital), class: "btn btn-link" %> |
<%= link_to 'Back', hospitals_path, class: "btn btn-link" %>

<script>
  $('.star-rating').raty({
    path: 'https://s3-us-west-2.amazonaws.com/morafamedapp/stars',
    readOnly: true,
    score: function() {
      return $(this).attr('data-score');
    }
  });
</script>

hospital.rb

class Hospital < ApplicationRecord
  mount_uploader :image, ImageUploader

  searchkick

  has_many :reviews

  def self.import(file)
    CSV.foreach(file.path, headers: true) do |row|
      Hospital.create! row.to_hash
    end
  end 

  def self.avg_rating
    Hospital.avg_rating
  end


end

show.html.erb

    <h3>
      <%= @hospital.name %>
    </h3>

    <%= @hospital.avg_rating %>

    <p><%= "#{@reviews.length} reviews" %></p>

误差

Showing /Users/oluwaseunmorafa/medaapp1/app/views/hospitals/show.html.erb where line #9 raised:
undefined method `avg_rating' for #<Hospital:0x007fd846496ee0>
Extracted source (around line #9):
7
8
9
10
11
12

    </h3>

    <%= @hospital.avg_rating %>

    <p><%= "#{@reviews.length} reviews" %></p>

Answer 1

在Hospital类中，您定义了类方法，而不是实例方法。因此，移除self.avg_rating方法，而不是写：

  def avg_rating
    review.average(:rating)
  end 

然后在视图中(在显示和索引中)，只需参考hospital.avg_rating来显示评级。