Rails 表单嵌套属性不允许参数答案

【问题标题】：Rails form nested attributes unpermitted parameterRails 表单嵌套属性不允许参数
【发布时间】：2018-05-30 18:25:06
【问题描述】：

以下代码抛出此错误：

不允许的参数：:conversation

在post_params 中有conversation_attributes 是否不允许conversations？我做错了什么？

posts_controller.rb

@post = @character.posts.create(post_params)
...

def post_params
  params.require(:post).permit( conversation_attributes: [ missives_attributes: [ :content ] ] )
end

post.rb

has_one :conversation, class_name: 'Postconversation', dependent: :destroy
accepts_nested_attributes_for :conversation

postconversation.rb

has_many :missives, class_name: 'Postmissive', dependent: :destroy
accepts_nested_attributes_for :missives

_post_form.html.erb

<%= f.fields_for :conversation do |ff| %>
  <%= ff.fields_for :missives do |fff| %>
    <%= hidden_field_tag :callsign, character.callsign %>
    <%= fff.text_area :content %>
    ...
  <% end %>
<% end %>

日志

Parameters: {"utf8"=>"✓", "authenticity_token"=>"mxHD...VoA==", "callsign"=>"baz", "post"=>{"conversation_attributes"=>{"missives_attributes"=>{"content"=>"Hello"}}}}

【问题讨论】：

标签： ruby-on-rails

【解决方案1】：

你可以试试：

def post_params
  params.require(:post).permit(conversation: [missives: [:content]])
end

更新：尝试用哈希显式包装它：

params.require(:post).permit({ conversation: [{ missives: [:content]}] })

【讨论】：

这会导致这个错误：ActiveRecord::AssociationTypeMismatch (Postconversation expected, got {"missives"=>{"content"=>"Hello"}} 这是 ActiveSupport::HashWithIndifferentAccess 的一个实例）：
尝试用哈希显式包装它。

【解决方案2】：

搞定了。必须使用f.fields_for :conversation_attributes。

posts_controller.rb

@post = @character.posts.create(post_params)
...

def post_params
  params.require(:post).permit( conversation_attributes: [ missives_attributes: [ :content ] ] )
end

post.rb

has_one :conversation, class_name: 'Postconversation', dependent: :destroy, inverse_of: :post
accepts_nested_attributes_for :conversation

postconversation.rb

belongs_to :post, inverse_of: :conversation
has_many :missives, class_name: 'Postmissive', dependent: :destroy, foreign_key: 'conversation_id', inverse_of: :conversation
accepts_nested_attributes_for :missives

postmissive.rb

belongs_to :conversation, class_name: 'Postconversation', foreign_key: 'conversation_id', inverse_of: :missives
validates :conversation, presence: true # validates :conversation_id does not work

_post_form.html.erb

<%= f.fields_for :conversation_attributes do |ff| %>
  <%= ff.fields_for 'missives_attributes[]', Postmissive.new do |fff| %>
    <%= hidden_field_tag :callsign, character.callsign %>
    <%= fff.text_area :content %>
    ...
  <% end %>
<% end %>

提交的参数

Parameters: {"utf8"=>"✓", "authenticity_token"=>"mxHD...VoA==", "callsign"=>"baz", "post"=>{"conversation_attributes"=>{"missives_attributes"=>[{"content"=>"Hello"}]}}}

【讨论】：