Question

为什么我收到此错误？：

TypeError（没有将Symbol隐式转换为整数）

在posts_controller中的create动作中：

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_attributes do |ff| %>
  <%= ff.fields_for :missives_attributes 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"}}}}

修改

根据这个问题，看起来我需要围绕我提交的参数使用方括号： Strong parameters with has_many gives "no implicit conversion of Symbol into Integer"

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

但是我如何在帖子中实现这个？

Answer 1

由于missives_attributes包含content

您使用<%= fff.text_area :content %>代表missives_attributes而非<%= f.text_area :content %>

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

Answer 2

我终于明白了：

<强> posts_controller.rb

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

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

<强> post.rb

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

<强> 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

<强> 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

<强> _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 %>

提交参数

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

备注

1）注意添加inverse_of:，以便Rails识别双向关联。没有这个，数据库保存失败。文档说它只需要与has_one和has_many一起使用，但是一些Stack Overflow答案说它也应该与belongs_to一起使用，这样就可以了我做了什么（belongs_to :post, inverse_of: :conversation和belongs_to :conversation, inverse_of: :missives）。进一步了解这一欢迎。

2）post_params很好。无需添加任何括号。

3）在postmissive.rb中，验证必须是validates :conversation，而不是validates :conversation_id。

4）Stephan Wiehr是对的，missives_attributes必须作为数组提交。感谢Kartikey Tanna关于如何实现这一目标的this答案。

Rails强参数TypeError没有将Symbol隐式转换为Integer

2 个答案: