如何在Rails中正确呈现部分模板？

Question

我有一个上市模型，用于表示转租（公寓）的列表，我创建了一个过滤器模型，作为用户根据自己的喜好过滤列表的一种方式。在我的Filter类中，它有一个方法列表，可以根据表单提交来查询列表。

class Filter < ActiveRecord::Base
  attr_accessible :air_conditioning, :available_rooms, :bathrooms, :furnished,  :negotiable, :new, :parking, :maximum_price, :private_bathroom, :show, :term, :total_rooms, :utilities, :washer_dryer
  serialize :term

  def listings
    @listings ||=find_listings
  end

private

  def find_listings
    listings=Listing.order(:price)
    listings=listings.where("listings.price <= ?", maximum_price) if maximum_price.present?
    listings=listings.where(total_rooms: total_rooms) if total_rooms.present?
    listings=listings.where(available_rooms: available_rooms) if available_rooms.present?
    listings=listings.where(bathrooms: bathrooms) if bathrooms.present?
    listings=listings.where(term: term)
    listings=listings.where(furnished: furnished)
    listings=listings.where(negotiable: negotiable)
    listings=listings.where(utilities: utilities)
    listings=listings.where(air_conditioning: air_conditioning)
    listings=listings.where(parking: parking)
    listings=listings.where(washer_dryer: washer_dryer)
    listings=listings.where(private_bathroom: private_bathroom)
    listings
  end

end

为了展示这些，我为过滤器创建了一个show方法，我想渲染一个局部模板。这就是我目前所拥有的，但它不会在/ listing

中呈现我创建的名为_listings.html.erb的模板

<p id="notice"><%= notice %></p>

<%= @filter.listings.size %>

<%= render @filter.listings  %>

这是模板

<div style="padding:5px">
<%= link_to 'New Listing', new_listing_path,{:style=>'', :class => "btn"} %>
<h1>Available Sublets</h1>

<table id="listingTable" class="table table-bordered table-hover">
  <tr>
    <th><%= link_to 'Filter', new_filter_path,{:style=>'', :class => "btn"} %><%= link_to 'Clear Filter', listings_path, {:style=>'', :class => "btn"} %></th>
    <th>Address</th>
    <th><u><%= "Price Per Month" %></u></th>
    <th>Description</th>
  </tr>
<% if @listings !=nil %>
    <% @listings.each do |listing| %>
      <tr onmouseover="this.style.cursor='pointer';"
      onclick="window.location.href = '<%= url_for(:controller => 'listings', :action => 'show', :id=>listing.id) %>' " >
        <td><%= image_tag listing.photo.url(:small) %></td>
        <td><%= listing.address %></td>
        <td>$<%= listing.price %></td>
        <td width="40%"><%= listing.description %></td>
      </tr>
    <% end %>
<% end %>
<% else if @listings==nil %>
    <p> Sorry, No Sublets Fit Your Criteria! </p>
<% end %>
</table>

我认为我的命名约定搞砸了，但我找不到正确的方法来执行此操作。任何人都有任何建议。此外，过滤器似乎总是空着。我用简单的过滤器测试了很多次，但它永远不会有效。如果有人在我的过滤器中看到错误，请随意指出它。谢谢！

Answer 1

如果调用render并将其传递给数组或关系，它实际上会调用partial上的单数形式。当你打电话

<%= render @filter.listings %>

它最终做的是以下内容：

<%= render :partial => 'listings/listing', :collection => @filter.listings %>

相当于

<% @filter.listings.each do |listing| %>
  <%= render listing %>
<% end %>

此外，`＆lt;％end％＆gt;周围或部分错误？ ＆lt;％else if ...％＆gt;，它应该是以下

<% if @listings != nil %>
    <% @listings.each do |listing| %>
      <tr onmouseover="this.style.cursor='pointer';"
      onclick="window.location.href = '<%= url_for(:controller => 'listings', :action => 'show', :id=>listing.id) %>' " >
        <td><%= image_tag listing.photo.url(:small) %></td>
        <td><%= listing.address %></td>
        <td>$<%= listing.price %></td>
        <td width="40%"><%= listing.description %></td>
      </tr>
    <% end %>
<% else %> (since you already checked if it was nil, you it is implied at this point the value is nil
    <p> Sorry, No Sublets Fit Your Criteria! </p>
<% end %>

我建议用以下方式编写它，因为它更像Ruby-esque

<% if @listings.blank? %>
    <p> Sorry, No Sublets Fit Your Criteria! </p>
<% else %>
     <% @listings.each do |listing| %>
      <tr onmouseover="this.style.cursor='pointer';"
      onclick="window.location.href = '<%= url_for(:controller => 'listings', :action => 'show', :id=>listing.id) %>' " >
        <td><%= image_tag listing.photo.url(:small) %></td>
        <td><%= listing.address %></td>
        <td>$<%= listing.price %></td>
        <td width="40%"><%= listing.description %></td>
      </tr>
    <% end %>
<% end %>

我最终处理这种情况的方法如下：

您的过滤器显示视图

<p id="notice"><%= notice %></p>

<%= @filter.listings.size %>
<div style="padding:5px">
<%= link_to 'New Listing', new_listing_path,{:style=>'', :class => "btn"} %>
<h1>Available Sublets</h1>

<table id="listingTable" class="table table-bordered table-hover">
  <tr>
    <th><%= link_to 'Filter', new_filter_path,{:style=>'', :class => "btn"} %><%= link_to 'Clear Filter', listings_path, {:style=>'', :class => "btn"} %></th>
    <th>Address</th>
    <th><u><%= "Price Per Month" %></u></th>
    <th>Description</th>
  </tr>
  <%= render(@filter.listings) ||  "<p> Sorry, No Sublets Fit Your Criteria! </p>".html_safe %>
</table>

您的'listings / _listing.html.erb'

<tr onmouseover="this.style.cursor='pointer';"
  onclick="window.location.href = '<%= url_for(listing) %>' " >
  <td><%= image_tag listing.photo.url(:small) %></td>
  <td><%= listing.address %></td>
  <td>$<%= listing.price %></td>
  <td width="40%"><%= listing.description %></td>
</tr>