Ruby on rails 如何在每个对象的索引页中显示平均评论评级

我有一个RubyonRails应用程序，应该可以帮助审查医院。 到目前为止，我遵循了一个详细的教程构建了一个相当可行的应用程序

我正在尝试向应用程序添加更多新功能

我希望用户能从主页上看到数据库中的医院列表，清楚地显示医院名称、图像和平均评论

我可以成功地在索引/主页上显示医院、图像和电话号码，但很难显示每家医院所有评论的平均评分。 这很奇怪，因为我在各个医院的展示页面上有完全相同的结构，而且在那里效果很好

我觉得我就在几步之外，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>

<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>

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

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

    <%= @hospital.avg_rating %>

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

搜寻

还没有评论。第一个写一篇！


|
美元（“.星级”）.raty({
路径：'https://s3-us-west-2.amazonaws.com/morafamedapp/stars',
只读：对，
分数：函数（）{
返回$（this.attr（'data-score'）；
}
});

医院.rb

<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>

<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>

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

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

    <%= @hospital.avg_rating %>

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

一级医院

show.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>

<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>

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

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

    <%= @hospital.avg_rating %>

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

错误

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>

Showing/Users/oluwaseunmorafa/medaapp1/app/views/hospitals/show.html.erb，其中第9行出现：
未定义的方法“平均额定值”#
提取的源（第9行附近）：
7.
8.
9
10
11
12

在您的

医院

类中，您定义了一个类方法而不是实例方法。因此，删除

self.avg_rating

方法，改为编写：

  def avg_rating
    review.average(:rating)
  end 

---

然后在您的视图中（在show And index中），您只需参考

hospital.avg_rating

即可显示评级

看起来您已经包含了大量不必要的代码，并且省略了许多实际相关的代码。您的问题应该包含一个包含重现问题所需的最少代码的问题。您正在询问

索引

视图的问题，但您的问题中没有包含该视图。也没有理由包括整个审查控制器。请编辑您的问题以删除不相关的代码，并包括您为索引视图编写的任何代码，即使它当前不起作用，以及它生成的任何错误。快速回答：按

医院id进行分组审核

，然后为每个集合计算其

平均值

。不那么快的答案是：这不是很好的规模。如果您计划扩展此应用程序以显示许多医院的平均评论，那么您应该将结果缓存在某个位置，而不是每次加载页面时重新计算。但如果这只是一个快速的小实验项目，那么别担心。嗨@oluwaseun morafa，你给了我们这么多信息真是太棒了。然而，这让你的问题很难理解。最好将重点放在问题领域，并使之更清楚。如果我没看错的话，你在展示一家医院的时候有问题，然后再展示？精明的？平均评论？哈，等等，在你编辑之后，我理解了问题：你想像在显示页面上那样在索引视图中显示平均值吗？（它在哪里工作？）@nathanvda。在您的show视图中，您可以计算

平均评级

，但您必须对索引中的每一行进行计算。我会将

avg_评级

的计算移动到

Hospital

类，然后您可以只编写

Hospital.avg_评级

，它将在索引和显示页面中工作。