AJAX更新accepts_nested_attributes_for局部文件

Question

我当前的工作环境是Rails 2.3.8 （导致公司未迁移到Rails 3的各种原因）。我正在尝试通过AJAX调用更新多模型表单的元素-
这个想法是根据用户选择或填写其他字段的方式替换某些下拉菜单。

我以前已经设法通过使用基于非表单的部分来实现此目的-
我现在的问题是，当部分基于form_for和fields_for时，会重现select下拉列表的AJAX更新。

对不起，下面的文字-我已经尝试过尽可能地减少它（代码本身确实可以在我的测试站点上工作）。

如何在爆发控制器中生成表单构建器元素，然后将其传递给category部分以代替identity_form？

任何指针都很棒：D

楷模

class Outbreak < ActiveRecord::Base
        has_many :incidents, :dependent => :destroy
        has_many :locations, :through => :incidents

     accepts_nested_attributes_for :locations, :allow_destroy => true, :reject_if => :all_blank
     accepts_nested_attributes_for :incidents, :allow_destroy => true, :reject_if => :all_blank
end

class Incident < ActiveRecord::Base
    belongs_to :outbreak
    belongs_to :location
    belongs_to :category
    belongs_to :subcategory
    belongs_to :subtype

end

class Location < ActiveRecord::Base
    has_many :incidents, :dependent => :destroy
     has_many :outbreaks, :thorugh => incidents
end

观看次数

_形成

<% form_for(@outbreak, :html => {:multipart => true}) do |form| %>

  <%= render :partial => 'outbreak_type_select', :locals => {:outbreak_types => @outbreak_types, :f => form } %>
   <% form.fields_for :incidents do |incident_form| %>
      <%= render :partial => 'category_select', :locals => {:categories => @categories, :incident_form => incident_form} %>
      <%= render :partial => 'subcategory_select', :locals => { :subcategories => @subcategories, :incident_form => incident_form } %>

   <% end %>
<% end %>

_outbreak_type_select

<% with_str = "'outbreak_type=' + value " %>
<% if @outbreak.id %>
<% with_str << "+ '&id=' + #{outbreak.id}" %>
<% end %>
<%= f.collection_select(:outbreak_type, @outbreak_types, :property_value, :property_value, {}, {:onchange => "#{remote_function(:url  => { :action => "update_select_menus"}, :with => with_str)}"}  ) %>

_category_select

调用update_select_menus之后如何生成事故表单

<%= incident_form.collection_select( :category_id, @categories, :id, :name, {:prompt   => "Select a category"}, {:onchange => "#{remote_function(:url  => { :action => "update_subcategory"}, :with => "'category_id='+value")}"}) %>

RJS

   begin
    page.replace_html 'outbreak_transmission_div', :partial => 'outbreaks/transmission_mode_select', :locals => {:transmission_modes => @transmission_modes }
   rescue
    page.insert_html :bottom, 'ajax_error', '<p>Error :: transmission modes update select</p>'
    page.show 'ajax_error'
   end
   begin
    page.replace_html 'incident_category_select', :partial => 'outbreaks/category_select', :locals => { :categories => @categories }  
   rescue
    page.insert_html :bottom, 'ajax_error', '<p>Error :: incident category update select</p>'
    page.show 'ajax_error'
   end

控制器

暴发

    def new
        @outbreak = Outbreak.new

        @outbreak.incidents.build
        @outbreak.locations.build

        #just the contents for the dropdowns
        @categories = Category.find(:all, :conditions => {:outbreak_type => "FOODBORNE"}, :order => "outbreak_type ASC")
        @subcategories = Subcategory.find(:all, :order => "category_id ASC")

    end

   def update_select_menus
      @outbreak_type = params[:outbreak_type].strip
      if params[:id]
        @outbreak = Outbreak.find(params[:id])
      else
        @outbreak = Outbreak.new
        @outbreak.incidents.build
              @outbreak.locations.build       
      end

      if @outbreak_type == "FOODBORNE"
          ob_type_query = "OUTBREAKS:TRANSMISSION_MODE:" << @outbreak_type
          @transmission_modes = Property.find(:all, :conditions => {:field => ob_type_query})

          ob_type_query = "INVESTIGATIONS:CATEGORY:" << @outbreak_type
          @sample_types = Property.find(:all, :conditions => {:field => ob_type_query})
          @categories = Category.find(:all, :conditions => { :outbreak_type => "FOODBORNE"})
          @subcategories = Subcategory.find(:all, :conditions => { :category_id => @categories.first.id})
          @subtypes = Subtype.find(:all, :conditions => { :subcategory_id => @subcategories.first.id})
      elsif @outbreak_type == "NON-FOODBORNE"
          ob_type_query = "OUTBREAKS:TRANSMISSION_MODE:" << @outbreak_type
          @transmission_modes = Property.find(:all, :conditions => {:field => ob_type_query})

          ob_type_query = "INVESTIGATIONS:CATEGORY:" << @outbreak_type
          @sample_types = Property.find(:all, :conditions => {:field => ob_type_query})
          @categories = Category.find(:all, :conditions => { :outbreak_type => "NON-FOODBORNE"})
          @subcategories = Subcategory.find(:all, :conditions => { :category_id => @categories.first.id})
          @subtypes = Subtype.find(:all, :conditions => { :subcategory_id => @subcategories.first.id})
     end

     respond_to do |format|
          format.html
          format.js
      end

  end

Answer 1

根据http://www.treibstofff.de/2009/07/12/ruby-on-rails-23-nested-attributes-
with-ajax-support/
找到了解决方法

这可能应该放在爆发助手中（在爆发控制器atm中）

    def update_select_menus
      @outbreak_type = params[:outbreak_type].strip
      #next_child_index will only be used if 
      @next_child_index ? params[:next_child_index] : 0
      if params[:id]
        @outbreak = Outbreak.find(params[:id])
      else
        @outbreak = Outbreak.new
        @outbreak.risks.build
        @outbreak.incidents.build
        @outbreak.locations.build

      end

      if @outbreak_type == "FOODBORNE"
          ob_type_query = "OUTBREAKS:TRANSMISSION_MODE:" << @outbreak_type
          @transmission_modes = Property.find(:all, :conditions => {:field => ob_type_query})

          ob_type_query = "INVESTIGATIONS:CATEGORY:" << @outbreak_type

          @sample_types = Property.find(:all, :conditions => {:field => ob_type_query})
          @categories = Category.find(:all, :conditions => { :outbreak_type => "FOODBORNE"})
          @subcategories = Subcategory.find(:all, :conditions => { :category_id => @categories.first.id})
          @subtypes = Subtype.find(:all, :conditions => { :subcategory_id => @subcategories.first.id})


      elsif @outbreak_type == "NON-FOODBORNE"
          ob_type_query = "OUTBREAKS:TRANSMISSION_MODE:" << @outbreak_type
          @transmission_modes = Property.find(:all, :conditions => {:field => ob_type_query})

          ob_type_query = "INVESTIGATIONS:CATEGORY:" << @outbreak_type

          @sample_types = Property.find(:all, :conditions => {:field => ob_type_query})
          @categories = Category.find(:all, :conditions => { :outbreak_type => "NON-FOODBORNE"})
          @subcategories = Subcategory.find(:all, :conditions => { :category_id => @categories.first.id})
          @subtypes = Subtype.find(:all, :conditions => { :subcategory_id => @subcategories.first.id})
     end

     @pathogen_types = Property.find(:all, :conditions => {:field => "PATHOGENS:CATEGORY"})
     @outbreak_types = Property.find(:all, :conditions => {:field => "OUTBREAKS:OUTBREAK_TYPE"} )


     render :update do |page|
         page.replace 'outbreak_transmission_div', :partial => 'transmission_mode_select_update'
         page.replace 'incident_category_select', :partial => 'incident_category_select_update'
         page.replace 'incident_subcategory_select', :partial => 'incident_subcategory_select_update'
         page.replace 'incident_subtype_select', :partial => 'incident_subtype_select_update'
     end

  end

在“爆发”视图中（尽管由于此部分与“事件”相关，所以它可能应该在该视图中显示）

    <% ActionView::Helpers::FormBuilder.new(:outbreak, @outbreak, @template, {}, proc{}).fields_for :incidents,{:child_index => @next_child_index} do |this_form| %>
<div id="incident_category_select">
<%= render :partial => 'category_select', :locals => {:incident_form => this_form } %>
</div>
<% end %>

ActionView :: Helpers :: FormBuilder用于生成所需的fields_for表单-网站文章对此进行了详细介绍。

结果索引由@next_child_index变量设置，该变量可以通过原始AJAX调用传递给控制器​​（例如@next_child_index =
1，那么结果表单元素名称将是 爆发[incidents_attributes] [1] [category_id]
）-我没有在此示例中使用此方法，因为尽管将来我希望该表单在每个爆发中都支持多个位置以进行此初始遍历，但它只接受一个位置-每个爆发均发生一个事件。

_category_select.erb部分（在“爆发”视图atm中）

<% with_str = "'category_id=' + value " %>
<% if @outbreak.id %>
<% with_str << "+ '&id=' + #{@outbreak.id}" %>
<% end %>
<%= incident_form.collection_select( :category_id, @categories, :id, :name, {:prompt   => "Select a category"}, {:onchange => "#{remote_function(:url  => { :action => "update_subcategory"}, :with => with_str)}"}) %>

with_str只是有选择地将爆发ID传递给控制器​​（如果存在）以找到爆发记录以生成表单，如果不存在则创建一个新的爆发以及关联的嵌套属性（如事件和位置）。

必须采用更整洁的方式进行操作-尤其是FormHelper并通过可选的with字符串传递爆发ID。