Question

它基于两个模型：公式和操作数。公式可以有很多操作数。每个操作数可以有很多或没有操作数。

我建立了一个多态关联，其中操作数属于操作，并且还有许多操作数作为运算符。公式有许多操作数作为操作本身。

我正在尝试构建一个可以处理此问题的nested_form，但是我被卡住了。我正在使用simple_nested_form。任何帮助将不胜感激。

class Formula < ActiveRecord::Base
  validates_presence_of :name, :client_id
  belongs_to :client

  has_many :operands, as: :operation, dependent: :destroy
  accepts_nested_attributes_for :operands, allow_destroy: true

end

class Operand < ActiveRecord::Base
  validates_presence_of :operator
  belongs_to :operation, polymorphic: true

  has_many :operands, as: :operation, dependent: :destroy
  accepts_nested_attributes_for :operands, allow_destroy: true

  OPERATOR_TYPES = ["+", "-", "*", "/"]
end

更新

基于上面的模型，我添加了formula_controller：

  def new 
    @formula.operands.build 
  end

在公式_form中，我添加了fields_for：operands

= simple_nested_form_for @formula, :html => { :class => 'form-vertical' } do |f|
  = f.error_notification

  .form-inputs
    .row
      .span3= f.input :name
    .well  
      = f.fields_for :operands
      = f.link_to_add t('helpers.links.add'), :operands

然后，部分_operands_fields，也渲染fields_for：operands

.well
  .row
    .span2= f.input :operator, collection: Operand::OPERATOR_TYPES
    .span3= f.input :numeric_operand
    .span3= f.link_to_remove t('helpers.links.remove')
  .well  
    = f.fields_for :operands
    = f.link_to_add t('helpers.links.add'), :operands

我认为这应该有效，但似乎在呈现公式表单时，它包含了字段_对于公式操作数。然后，在这部分内部，而不是包括“添加”，它呈现另一个操作数字段，依此类推，以无限循环结束，如下所示：

  User Load (0.4ms)  SELECT  "users".* FROM "users"  WHERE "users"."id" = 1  ORDER BY "users"."id" ASC LIMIT 1
  Client Load (0.2ms)  SELECT  "clients".* FROM "clients"  WHERE "clients"."id" = ? LIMIT 1  [["id", 1]]
  Rendered formulas/_operand_fields.html.haml (48.4ms)
  Rendered formulas/_operand_fields.html.haml (9.0ms)
  Rendered formulas/_operand_fields.html.haml (7.5ms)
  Rendered formulas/_operand_fields.html.haml (9.1ms)
  Rendered formulas/_operand_fields.html.haml (8.8ms)
  Rendered formulas/_operand_fields.html.haml (9.2ms)
  Rendered formulas/_operand_fields.html.haml (9.3ms)
  Rendered formulas/_operand_fields.html.haml (9.5ms)
  Rendered formulas/_operand_fields.html.haml (17.7ms)
  Rendered formulas/_operand_fields.html.haml (52.4ms)
  Rendered formulas/_operand_fields.html.haml (10.4ms)
  Rendered formulas/_operand_fields.html.haml (11.3ms)

如何解决这个问题？

Rails nested_form用于递归模型关联

0 个答案: