使用嵌套属性和 has_one :through 关系的“不允许的参数”答案

【问题标题】："Unpermitted Parameters" using nested attributes and a has_one :through relationship使用嵌套属性和 has_one :through 关系的“不允许的参数”
【发布时间】：2014-05-16 18:34:45
【问题描述】：

我正在使用 Papercrop gem 来裁剪我的缩略图。它在我的用户控制器上的其他地方工作得很好，但是我试图用 has_one :through 关系进行裁剪，并且嵌套表单没有发挥作用。

一些示例参数：

Parameters: {"utf8"=>"✓", "authenticity_token"=>"t3BsHf6nxAhM9zcRUJfy3nMoLVQAJF/KLbWwqrxeYuk=", "project"=>{"uploaded_image_original_w"=>"960.0", "uploaded_image_original_h"=>"640.0", "uploaded_image_box_w"=>"500", "uploaded_image_crop_x"=>"330", "uploaded_image_crop_y"=>"0", "uploaded_image_crop_w"=>"607", "uploaded_image_crop_h"=>"607", "uploaded_image_aspect"=>"1.0"}, "commit"=>"Save", "profile_name"=>"Benji", "id"=>"1"}

以及随之而来的错误：

Unpermitted parameters: uploaded_image_original_w, uploaded_image_original_h, uploaded_image_box_w, uploaded_image_crop_x, uploaded_image_crop_y, uploaded_image_crop_w, uploaded_image_crop_h, uploaded_image_aspect

项目.rb

class Project < ActiveRecord::Base
    belongs_to :user

    has_one :thumbnail, :dependent => :destroy
    has_one :image, through: :thumbnail
    accepts_nested_attributes_for :image
end

projects_controller.rb（image_attribute attr_accessors 由 Papercrop gem 完成）

def crop_params
    params.require(:project).permit(image_attributes: [:uploaded_image_original_w, :uploaded_image_original_h, 
                                                     :uploaded_image_box_w, :uploaded_image_crop_x,
                                                     :uploaded_image_crop_y, :uploaded_image_crop_w, 
                                                     :uploaded_image_crop_h, :uploaded_image_aspect])
end

为什么不允许这些属性？

编辑：

添加 fields_for around 改变了我的错误，现在唯一不允许的参数是“image”

<%= form_for(@project.thumbnail.image, :as => :project,:url => project_thumbnail_path(@user, @project)) do |f| %>
    <%= f.fields_for :image, @project.thumbnail.image do |pf| %>
        <%= pf.cropbox :uploaded_image, :width => 500 %>
    <%= pf.crop_preview :uploaded_image, :width => 150 %>
    <%= pf.submit 'Save' %>
    <% end %>
<% end %>

【问题讨论】：

标签： ruby-on-rails ruby-on-rails-4

【解决方案1】：

查看您的参数，您没有将 image_attributes: 作为参数传递：

"project"=>{"uploaded_image_original_w"=>"960.0", "uploaded_image_original_h"=>"640.0", "uploaded_image_box_w"=>"500", "uploaded_image_crop_x"=>"330", "uploaded_image_crop_y"=>"0", "uploaded_image_crop_w"=>"607", "uploaded_image_crop_h"=>"607", "uploaded_image_aspect"=>"1.0"}

您可能没有在视图中设置f.fields_for（而只是按原样使用元素）。你有你的表单代码吗？

要使上述参数正常工作，您需要这些 strong_params:

params.require(:project).permit(:uploaded_image_original_w, :uploaded_image_original_h, 
                                                     :uploaded_image_box_w, :uploaded_image_crop_x,
                                                     :uploaded_image_crop_y, :uploaded_image_crop_w, 
                                                     :uploaded_image_crop_h, :uploaded_image_aspect)

【讨论】：

您好，谢谢您的帮助。这是我的表单 - <%= form_for(@project.thumbnail.image, :as => :project,:url => project_thumbnail_path(@user, @project)) do |f| %> <%= f.cropbox :uploaded_image, :width => 500 %> <%= f.crop_preview :uploaded_image, :width => 150 %> <%= f.submit 'Save' %> <% end %> 我认为需要将 strong_params 保留在其中，因为 attr_accessors 在图像模型中。
我还尝试将字段包装在 fields_for 标记中给我一个未定义的 nil:NilClass 错误方法，因为我认为它不再引用附件。
是的，f.fields_for 要求您在尝试使用之前构建嵌套对象。尝试将 @project.thumbnail.image.build 放入您的 new 方法中——我会在修复一些东西后一分钟内更好地查看
已经建立了一个缩略图，这是更新方法的一部分&感谢你有机会，我一直在兜圈子！
我已经尝试过了，但是我得到了未经许可的参数“图像”：<%= form_for(@project.thumbnail.image, :as => :project,:url => project_thumbnail_path(@user, @project)) do |f| %> <%= f.fields_for :image, @project.thumbnail.image do |pf| %> <%= pf.cropbox :uploaded_image, :width => 500 %> <%= pf.crop_preview :uploaded_image, :width => 150 %> <%= pf.submit 'Save' %> <% end %> <% end %>