不能讓孩子屬性通過軌道加載ActiveModel控制檯父模型保存:: UnknownAttributeError：

Question

所以我一直在想測試我的模型，看看我是否可以通過軌道控制檯中使用Gallery.new(:picture => File.new('E:\Owner (Backup)\Pictures\Skateboard 1.jpg', 'r'))添加圖片，但我可以上市了以下錯誤下面。我這樣做是因爲我無法得到一張圖片以保存在我的Rails應用程序中，我只是重新渲染了new模板，並在新視圖中部分列出了表單。

我不知道如何任何人，因爲從我可以看到我的模型都很好故障排除這些錯誤。而且我的遷移看起來也很好。我想accept_nested_attributes_for允許Picture模型屬性通過Gallery模型傳遞。

在控制檯中的錯誤是

irb(main):002:0> Gallery.new(:picture => File.new('E:\Owner (Backup)\Pictures\Skateboard 1.jpg', 'r')) 
ActiveModel::UnknownAttributeError: unknown attribute 'picture' for Gallery. 
    from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/activemodel-5.0.1/lib/active_model/attribute_assignment.rb:48:in `_assign_attribute' 
    from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/activemodel-5.0.1/lib/active_model/attribute_assignment.rb:40:in `block in _assign_attributes' 
    from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/activemodel-5.0.1/lib/active_model/attribute_assignment.rb:39:in `each' 
    from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/activemodel-5.0.1/lib/active_model/attribute_assignment.rb:39:in `_assign_attributes' 
    from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/activerecord-5.0.1/lib/active_record/attribute_assignment.rb:26:in `_assign_attributes' 
    from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/activemodel-5.0.1/lib/active_model/attribute_assignment.rb:33:in `assign_attributes' 
    from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/activerecord-5.0.1/lib/active_record/core.rb:319:in `initialize' 
    from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/activerecord-5.0.1/lib/active_record/inheritance.rb:65:in `new' 
    from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/activerecord-5.0.1/lib/active_record/inheritance.rb:65:in `new' 
    from (irb):2 
    from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/railties-5.0.1/lib/rails/commands/console.rb:65:in `start' 
    from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/railties-5.0.1/lib/rails/commands/console_helper.rb:9:in `start' 
    from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/railties-5.0.1/lib/rails/commands/commands_tasks.rb:78:in `console' 
    from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/railties-5.0.1/lib/rails/commands/commands_tasks.rb:49:in `run_command!' 
    from C:/RailsInstaller/Ruby2.2.0/lib/ruby/gems/2.2.0/gems/railties-5.0.1/lib/rails/commands.rb:18:in `<top (required)>' 
    from bin/rails:4:in `require' 
    from bin/rails:4:in `<main>'irb(main):003:0> ^C 
irb(main):003:0> 

我的模型，畫廊

class Gallery < ApplicationRecord 
    has_many :pictures 
    validates :name, presence: true 
    validates :cover, presence: true 
    accepts_nested_attributes_for :pictures, allow_destroy: true 
end 

圖片

class Picture < ApplicationRecord 
    belongs_to :gallery 
    validates :gallery_id, presence: true 
    validates :picture, presence: true 
    mount_uploader :picture, PictureUploader 
    serialize :picture, JSON 
end 

遷移，畫廊

class CreateGalleries < ActiveRecord::Migration[5.0] 
    def change 
    create_table :galleries do |t| 
     t.string :name 
     t.integer :cover 

     t.timestamps 
    end 
    end 
end 

張

圖片

class CreatePictures < ActiveRecord::Migration[5.0] 
    def change 
    create_table :pictures do |t| 
     t.integer :gallery_id 
     t.string :picture 

     t.timestamps 
    end 
    end 
end 

Answer 1

ActiveModel::UnknownAttributeError: unknown attribute 'picture' for Gallery.

你做錯了。你應該副的圖片與畫廊實例，而不是把它當作一個屬性的畫廊模式。

g = Gallery.new(name: 'Some Name', cover: 'Some Cover') 
g.save! 
p = g.pictures.new(picture: File.new('E:\Owner (Backup)\Pictures\Skateboard 1.jpg', 'r')) 
p.save!