Ruby on rails 4 由于强参数，嵌套表单参数不起作用

我有一个模型声明，它有很多成本：

class Declaration < ActiveRecord::Base
  has_many :costs
  accepts_nested_attributes_for :costs
end

class Cost < ActiveRecord::Base
  belongs_to :declaration
end

当然还有表格，所以当我提交表格时，我会在日志中看到：

Started POST "/users/3/declarations" for 127.0.0.1 at 2013-09-05 19:12:38 +0200
Processing by DeclarationsController#create as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"mhaznOuBy/zj7LA/nIpDTy7X2u5UrR+0jleJsFid/JU=", "declaration"=>{"user_id"=>"3", "cost"=>{"cost_date(3i)"=>"", "cost_date(2i)"=>"", "cost_date(1i)"=>"", "projectuser_id"=>"", "description"=>"", "amount_foreign"=>"", "rate"=>"", "amount"=>""}}, "commit"=>"Opslaan", "user_id"=>"3"}
  User Load (0.7ms)  SELECT "users".* FROM "users" WHERE "users"."id" = 3 ORDER BY "users"."id" ASC LIMIT 1
Unpermitted parameters: cost

那么，为什么我要获得一个未经许可的参数

cost

更新：声明表格添加如下：

- if can? :create, Declaration
  = form_for [current_user, @declaration] do |f|
    = f.hidden_field :user_id, value: current_user.id

    .row
      .page-header
        .span7
          %h1.title
            %i{ class: "icon-coffee icon-large" }
            = I18n.t('.declaration.add_title')
        .span5
          .action
            - if can? :create, Declaration
              = link_to I18n.t('.general.cancel'), user_declarations_path(current_user), class: 'btn'
              = f.submit(class: 'btn', value: I18n.t('.general.save'))
    .row
      .span12
        = render "layouts/error_messages", target: @declaration

    .row
      .span12
        = render "form", f: f

以及呈现形式：

.row
  .span12
    %table.table.table-striped#declarations
      %thead
        %tr
          %th= I18n.t('.cost.cost_date')
          %th= I18n.t('.cost.project')
          %th= I18n.t('.cost.description')
          %th= I18n.t('.cost.amount_foreign')
          %th= I18n.t('.cost.rate')
          %th= I18n.t('.cost.amount')
      %tbody
        - @costs.each do |cost|
          = f.fields_for cost, html: { class: "form-inline"} do |c|
            %tr
              %td{ "data-title" => "#{I18n.t('.cost.cost_date')}" }= c.date_select :cost_date, { include_blank: true, default: nil }
              %td{ "data-title" => "#{I18n.t('.cost.project')}" }= c.collection_select :projectuser_id, @projectusers, :id, :full_name, include_blank: true
              %td{ "data-title" => "#{I18n.t('.cost.description')}" }= c.text_field :description, class: "input-large"
              %td{ "data-title" => "#{I18n.t('.cost.amount_foreign')}" }= c.text_field :amount_foreign, class: "input-small", type: :number, step: "any"
              %td{ "data-title" => "#{I18n.t('.cost.rate')}" }= c.text_field :rate, class: "input-small", type: :number, step: "any"
              %td{ "data-title" => "#{I18n.t('.cost.amount')}" }= c.text_field :amount, class: "input-small", type: :number, step: "any"

有许可证！我收到以下错误消息：

Started POST "/users/3/declarations" for 127.0.0.1 at 2013-09-09 09:29:44 +0200
Processing by DeclarationsController#create as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"jQwy7psQwixneWF8DezrR/Wo5VKU/dpfz+sosiatm9c=", "declaration"=>{"user_id"=>"3", "cost"=>{"cost_date(3i)"=>"", "cost_date(2i)"=>"", "cost_date(1i)"=>"", "projectuser_id"=>"", "description"=>"", "amount_foreign"=>"", "rate"=>"", "amount"=>""}}, "commit"=>"Opslaan", "user_id"=>"3"}
  User Load (0.6ms)  SELECT "users".* FROM "users" WHERE "users"."id" = 3 ORDER BY "users"."id" ASC LIMIT 1
Completed 500 Internal Server Error in 6ms

ArgumentError - wrong number of arguments (6 for 0):
  app/controllers/declarations_controller.rb:70:in `declaration_params'
  app/controllers/declarations_controller.rb:21:in `create'

---

第一印象是您返回了三个cost_date参数。我认为这需要作为数组返回。您的参数将是：

 def declaration_params
 params.require(:declaration).permit(:approval_date, :submit_date, :status, :user_id, :declaration_number,
  costs_attributes: [:id, :description, :amount_foreign, :rate, :amount, :projectuser_id, :cost_date =>[]])
end

然后，您的web服务器将无法恢复：

... "cost"=>{"cost_date(3i)"=>"", "cost_date(2i)"=>"", "cost_date(1i)"=>"",... 

它应该得到：

"cost"=>{"cost_date"=>["","",""],...

---

虽然没有看到形式，我不知道这是否是你想要实现的

似乎要改变这一点：

  - @costs.each do |cost|
      = f.fields_for cost, html: { class: "form-inline"} do |c|

为此：

= f.fields_for(:costs) do |c|

因为现在所有的成本记录都被保存了。在控制器中，我现在有：

@declaration = Declaration.new
10.times do |n|
  @declaration.costs.build
end

---

我现在剩下的唯一问题是它保存了空的成本记录。

您可以发布表单的html.erb吗？另外，您可以通过更改

params.require（：声明）。permit…

到

params.require（：声明）。permit来运行一些疑难解答吗查看发生了什么？我还没有研究
许可证方法，让您觉得它足够安全，可以在生产中使用，但它会突出显示Rails单数/复数是否有问题，即成本与成本…可能是它基于获得三个参数拒绝了整个成本哈希值
“cost”=>{“cost\u date（3i）”=>，“cost\u date（2i）”=>，“cost\u date（1i）”=>“
从表单中？它将cost_date（1i）识别为：cost_date参数？具有许可证！它返回：“参数数目错误（0为6）”？可能与我添加的视图重复。那么，您是否尝试过上述代码？您是否应该获得3个不同的cost_date（）返回的参数？对于一个表行来说这似乎很奇怪。这里的成本日期似乎不是问题。使用
10.times do
将提供十条新记录，无论发生什么情况。您应该使用
。每个
方法。即
成本。每个do…
等等。
@declaration = Declaration.new
10.times do |n|
  @declaration.costs.build
end