Rails动态表单问题

Question

我正在开发基于http://railscasts.com/episodes/197-nested-model-form-part-2 的动态表单。

我有这个链接： 意见/共享/_new_field.html.erb

<%= link_to_add_fields "Add Field", f, :application_fields, @current_section.id %>

这里是： helpers/application_helper.rb

# Generates a link_to add a new application field.
def link_to_add_fields(name, f, association, section_id) 
    new_object = f.object.send(association).klass.new
    id = new_object.object_id
    fields = f.fields_for(association, new_object, child_index: id) do |builder|
        render(association.to_s.singularize + "_fields", f: builder) 
    end
    link_to(name, '#', class: "add_fields buttonS bBlue button", data: {id: id, fields: fields.gsub("\n", ""), section_id: section_id})
end

它会生成一个表单，当我填写字段并提交时，它会生成 params 哈希：

Parameters: {"utf8"=>"✓", "authenticity_token"=>"Cl8XQNZeKRMtpdE0MLNhEX3by67bEcntjaAxygsduyo=", "application"=>{"application_fields_attributes"=>{"1380071101589"=>{"field_name"=>"RRR", "field_type"=>"textfield", "required"=>"0", "_destroy"=>"false"}}}, "commit"=>"Create", "id"=>"1", "section_id"=>"2"}

这是控制器方法：

...
@application = current_company.applications.find(params[:id])
@application.update_attributes(params[:application])

if @application.update_attributes(params[:application])
...

问题

使用我当前的控制器方法，它不会将 section_id 保存到 ApplicationField 行。

I also tried this in my controller method:
...
@application = current_company.applications.find(params[:id])
@application.assign_attributes(params[:application])
@application.section_id = params[:section_id]

if @application.save
...

但这会产生错误：

NoMethodError - undefined method `section_id=' for #<Application:0x007f8300138ca8>

我不知道我需要做什么才能将部分 id 保存到 ApplicationField 行。

参考模型

class Application < ActiveRecord::Base
    belongs_to :company
    has_many :application_fields, :dependent => :destroy
    accepts_nested_attributes_for :application_fields, :allow_destroy => true
    attr_accessible :application_name, :company_id, :application_fields_attributes
end

class ApplicationField < ActiveRecord::Base
    belongs_to :application
    has_many :application_fields_values, :dependent => :destroy
    attr_accessible :field_name, :field_type, :xposition, :yposition, :required, :application_id, :template_id, :options, :section_id 
end

辅助方法中 field.inspect 的输出：

"<div class=\"application_field formRow add_fields_form\" id=\"new_application_field\" remote=\"true\">\n    \n    <div class=\"formRow\">\n\t    <label for=\"application_application_fields_attributes_70100276854720_field_name\">Field name</label>\n\t    <input id=\"application_application_fields_attributes_70100276854720_field_name\" name=\"application[application_fields_attributes][70100276854720][field_name]\" size=\"30\" type=\"text\" />\n\t</div>\n    \n    <div class=\"formRow\">\n\t    <label for=\"application_application_fields_attributes_70100276854720_field_type\">Field type</label>\n\t    <select class=\"select\" id=\"field_type_dropdown\" name=\"application[application_fields_attributes][70100276854720][field_type]\"><option value=\"textfield\">Textfield</option>\n<option value=\"checkbox\">Checkbox</option>\n<option value=\"dropdown\">Dropdown</option>\n<option value=\"biglabel\">Big Label</option>\n<option value=\"smalllabel\">Small Label</option></select>\n\t</div>\n    \n    <div class=\"formRow\">\n\t    <input name=\"application[application_fields_attributes][70100276854720][required]\" type=\"hidden\" value=\"0\" /><input class=\"check\" id=\"application_application_fields_attributes_70100276854720_required\" name=\"application[application_fields_attributes][70100276854720][required]\" type=\"checkbox\" value=\"1\" />\n\t    <label for=\"application_application_fields_attributes_70100276854720_required\">Required</label>\n\t</div>\n    \n    <!-- Need to store the hidden field _destroy here so we can access it via jQuery -->\n    <input id=\"application_application_fields_attributes_70100276854720__destroy\" name=\"application[application_fields_attributes][70100276854720][_destroy]\" type=\"hidden\" value=\"false\" />\n    \n    <div class=\"grid1\" align=\"center\">\n        \n    </div>\n    \n    <div id=\"new_field_buttons\" class=\"formRow\">\n        <div id=\"new_field_buttons\" class=\"fluid sideWidget\">\n            <div class=\"grid6\">\n                <input class=\"buttonS bBlue\" name=\"commit\" type=\"submit\" value=\"Create\" />\n            </div>\n            <div class=\"grid6\">\n                <input id=\"cancel_new_field\" class=\"buttonS bRed\" type=\"button\" value=\"Cancel\">\n            </div>\n        </div>\n    </div>\n    <div class=\"clear\"></div>\n</div>\n"
ributes][70100276854720][_destroy]\" type=\"hidden\" value=\"false\" />\n    \n    <div class=\"grid1\" align=\"center\">\n        \n    </div>\n    \n    <div id=\"new_field_buttons\" class=\"formRow\">\n        <div id=\"new_field_buttons\" class=\"fluid sideWidget\">\n            <div class=\"grid6\">\n                <input class=\"buttonS bBlue\" name=\"commit\" type=\"submit\" value=\"Create\" />\n            </div>\n            <div class=\"grid6\">\n                <input id=\"cancel_new_field\" class=\"buttonS bRed\" type=\"button\" value=\"Cancel\">\n            </div>\n        </div>\n    </div>\n    <div class=\"clear\"></div>\n</div>\n"
             <input class=\"buttonS bBlue\" name=\"commit\" type=\"submit\" value=\"Create\" />\n            </div>\n            <div class=\"grid6\">\n                <input id=\"cancel_new_field\" class=\"buttonS bRed\" type=\"button\" value=\"Cancel\">\n            </div>\n        </div>\n    </div>\n    <div class=\"clear\"></div>\n</div>\n"
div class=\"clear\"></div>\n</div>\n"

Answer 1

不要将section_id 传递给link_to 方法，而是尝试将其作为变量传递给render 方法，如下所示：

render(association.to_s.singularize + "_fields", f: builder, section_id: section_id)

这样，您只需在 application_field_fields 部分中插入一个隐藏字段，将section_id 添加到发布到控制器的表单数据中：

<%= f.hidden_field :section_id, :value => section_id %>