Question

我刚接触ruby on rails，我将创建在线租赁系统。

这是位置基础模型

app/models/state.rb
Class State < ActiveRecord::Base
has_many :provinces
end

app/models/province.rb
Class Province < ActiveRecord::Base
belongs_to :state
has_many :districts
end

app/models/district.rb
Class District < ActiveRecord::Base
belongs_to :province
has_many :cities
end

app/models/city.rb
Class City < ActiveRecord::Base
belongs_to :district
end

第一个问题是如何在下面显示所有内容

阿拉斯加
加利福尼亚
- 洛杉矶
- 弗雷斯诺
  - Cincotta（弗雷斯诺）
  - 哈蒙德（弗雷斯诺）
  - 梅尔文（弗雷斯诺）
    - Melvin 1
    - Melvin 2
亚利桑那
科罗拉多

第二个问题是，如何创建面包屑所有模型

加利福尼亚＆gt;＆gt;弗雷斯诺＆gt;＆gt;梅尔文＆gt;＆gt;梅尔文1

Answer 1

您可能希望在数据对象中引入层次结构。这可以通过几种方式完成。看看the ancestry gem

如果你想硬编码：

# locations_controller.rb
def index
  @locations = State.all
end

# app/views/locations/index.html.erb
<ul>
  <%= render @locations %>
</ul>

# app/views/locations/_state.html.erb
<li>
  <%= state.name %>
  <% if state.provinces.present? %>
    <ul>
      <%= render state.provinces %>
    </ul>
  <% end %>
</li>

# app/views/locations/_province.html.erb
<li>
  <%= province.name %>
  <% if province.districts.present? %>
    <ul>
      <%= render province.districts %>
    </ul>
  <% end %>
</li>

# app/views/locations/_district.html.erb
<li>
  <%= district.name %>
  <% if district.cities.present? %>
    <ul>
      <%= render district.cities %>
    </ul>
  <% end %>
</li>   

# app/views/locations/_city.html.erb
<li>
  <%= city.name %>
</li>

对于Breadcrumbs，您需要在每个模型中引入一个祖先方法。 e.g。

class City
  ...
  def ancestry
    district.ancestry << self
  end
  ...
end

# ... other classes

class State
  ...
  def ancestry
    [self]
  end
end

然后你可以渲染面包屑部分

# app/views/layout.html.erb
<%= render partial: 'shared/breadcrumbs', locals: { ancestry: @some_instance.
def breadcrumbs(ancestry)
  ancestry
end

# app/views/shared/_breadcrumbs.html.erb
<ul>
  <% ancestry.each do |location| %>
    <li>
      <%= link_to location.name, url_for(location) %>
    </li>
  <% end %>
</ul>

在轨道上将所有模型联系在红宝石上

1 个答案: