Ruby on rails 4 Rails 4使用carrierwave上传多个图像或文件

如何使用Rails 4和CarrierWave从文件选择窗口上载多个图像？我有一个

post\u控制器

和

post\u附件

型号。我该怎么做

有人能举个例子吗？有没有一个简单的方法

这是使用rails 4中的carrierwave从头开始上载多个图像的解决方案

或者您可以找到工作演示：

只需遵循以下步骤即可。

rails new multiple_image_upload_carrierwave

在gem文件中

gem 'carrierwave'
bundle install
rails generate uploader Avatar 

创建后脚手架

rails generate scaffold post title:string

rails generate scaffold post_attachment post_id:integer avatar:string

rake db:migrate

创建后附着脚手架

rails generate scaffold post title:string

rails generate scaffold post_attachment post_id:integer avatar:string

rake db:migrate

在post.rb中

class Post < ActiveRecord::Base
   has_many :post_attachments
   accepts_nested_attributes_for :post_attachments
end

class PostAttachment < ActiveRecord::Base
   mount_uploader :avatar, AvatarUploader
   belongs_to :post
end

def show
   @post_attachments = @post.post_attachments.all
end

def new
   @post = Post.new
   @post_attachment = @post.post_attachments.build
end

def create
   @post = Post.new(post_params)

   respond_to do |format|
     if @post.save
       params[:post_attachments]['avatar'].each do |a|
          @post_attachment = @post.post_attachments.create!(:avatar => a)
       end
       format.html { redirect_to @post, notice: 'Post was successfully created.' }
     else
       format.html { render action: 'new' }
     end
   end
 end

 private
   def post_params
      params.require(:post).permit(:title, post_attachments_attributes: [:id, :post_id, :avatar])
   end

<%= form_for(@post, :html => { :multipart => true }) do |f| %>
   <div class="field">
     <%= f.label :title %><br>
     <%= f.text_field :title %>
   </div>

   <%= f.fields_for :post_attachments do |p| %>
     <div class="field">
       <%= p.label :avatar %><br>
       <%= p.file_field :avatar, :multiple => true, name: "post_attachments[avatar][]" %>
     </div>
   <% end %>

   <div class="actions">
     <%= f.submit %>
   </div>
<% end %>

<p id="notice"><%= notice %></p>

<p>
  <strong>Title:</strong>
  <%= @post.title %>
</p>

<% @post_attachments.each do |p| %>
  <%= image_tag p.avatar_url %>
  <%= link_to "Edit Attachment", edit_post_attachment_path(p) %>
<% end %>

<%= link_to 'Edit', edit_post_path(@post) %> |
<%= link_to 'Back', posts_path %>

<%= image_tag @post_attachment.avatar %>
<%= form_for(@post_attachment) do |f| %>
  <div class="field">
    <%= f.label :avatar %><br>
    <%= f.file_field :avatar %>
  </div>
  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

def update
  respond_to do |format|
    if @post_attachment.update(post_attachment_params)
      format.html { redirect_to @post_attachment.post, notice: 'Post attachment was successfully updated.' }
    end 
  end
end

  <%= f.fields_for :post_attachments, PostAttachment.new do |ff| %>
    <div class="field">
      <%= ff.label :avatar %><br>
      <%= ff.file_field :avatar, :multiple => true, name: "post[post_attachments_attributes][][avatar]" %>
    </div>
  <% end %>

class Post < ApplicationRecord
    ...
    accepts_nested_attributes_for :post_attachments, allow_destroy: true
end

 <% f.object.post_attachments.each do |post_attachment| %>
    <% if post_attachment.id %>

      <%

      post_attachments_delete_params =
      {
      post:
        {              
          post_attachments_attributes: { id: post_attachment.id, _destroy: true }
        }
      }

      %>

      <%= link_to "Delete", post_path(f.object.id, post_attachments_delete_params), method: :patch, data: { confirm: 'Are you sure?' } %>

      <br><br>
    <% end %>
  <% end %>

在views/posts/_form.html.erb中

class Post < ActiveRecord::Base
   has_many :post_attachments
   accepts_nested_attributes_for :post_attachments
end

class PostAttachment < ActiveRecord::Base
   mount_uploader :avatar, AvatarUploader
   belongs_to :post
end

def show
   @post_attachments = @post.post_attachments.all
end

def new
   @post = Post.new
   @post_attachment = @post.post_attachments.build
end

def create
   @post = Post.new(post_params)

   respond_to do |format|
     if @post.save
       params[:post_attachments]['avatar'].each do |a|
          @post_attachment = @post.post_attachments.create!(:avatar => a)
       end
       format.html { redirect_to @post, notice: 'Post was successfully created.' }
     else
       format.html { render action: 'new' }
     end
   end
 end

 private
   def post_params
      params.require(:post).permit(:title, post_attachments_attributes: [:id, :post_id, :avatar])
   end

<%= form_for(@post, :html => { :multipart => true }) do |f| %>
   <div class="field">
     <%= f.label :title %><br>
     <%= f.text_field :title %>
   </div>

   <%= f.fields_for :post_attachments do |p| %>
     <div class="field">
       <%= p.label :avatar %><br>
       <%= p.file_field :avatar, :multiple => true, name: "post_attachments[avatar][]" %>
     </div>
   <% end %>

   <div class="actions">
     <%= f.submit %>
   </div>
<% end %>

<p id="notice"><%= notice %></p>

<p>
  <strong>Title:</strong>
  <%= @post.title %>
</p>

<% @post_attachments.each do |p| %>
  <%= image_tag p.avatar_url %>
  <%= link_to "Edit Attachment", edit_post_attachment_path(p) %>
<% end %>

<%= link_to 'Edit', edit_post_path(@post) %> |
<%= link_to 'Back', posts_path %>

<%= image_tag @post_attachment.avatar %>
<%= form_for(@post_attachment) do |f| %>
  <div class="field">
    <%= f.label :avatar %><br>
    <%= f.file_field :avatar %>
  </div>
  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

def update
  respond_to do |format|
    if @post_attachment.update(post_attachment_params)
      format.html { redirect_to @post_attachment.post, notice: 'Post attachment was successfully updated.' }
    end 
  end
end

  <%= f.fields_for :post_attachments, PostAttachment.new do |ff| %>
    <div class="field">
      <%= ff.label :avatar %><br>
      <%= ff.file_field :avatar, :multiple => true, name: "post[post_attachments_attributes][][avatar]" %>
    </div>
  <% end %>

class Post < ApplicationRecord
    ...
    accepts_nested_attributes_for :post_attachments, allow_destroy: true
end

 <% f.object.post_attachments.each do |post_attachment| %>
    <% if post_attachment.id %>

      <%

      post_attachments_delete_params =
      {
      post:
        {              
          post_attachments_attributes: { id: post_attachment.id, _destroy: true }
        }
      }

      %>

      <%= link_to "Delete", post_path(f.object.id, post_attachments_delete_params), method: :patch, data: { confirm: 'Are you sure?' } %>

      <br><br>
    <% end %>
  <% end %>

在rails 3中，不需要定义强参数，而且您可以在模型中定义属性\u accessible，并接受\u嵌套的\u属性来发布模型，因为在rails 4中，属性accessible是不推荐使用的

---

对于编辑附件，我们不能一次修改所有附件。因此，我们将逐个替换附件，或者您可以根据您的规则进行修改，这里我只向您展示如何更新任何附件。

当使用关联

@post.post\u attachments

时，您无需设置

post\u id

此外，我还了解了如何更新多文件上载，并对其进行了一些重构。这个密码是我的，但你明白了

def create
  @motherboard = Motherboard.new(motherboard_params)
  if @motherboard.save
    save_attachments if params[:motherboard_attachments]
    redirect_to @motherboard, notice: 'Motherboard was successfully created.'
  else
    render :new
  end
end


def update
  update_attachments if params[:motherboard_attachments]
  if @motherboard.update(motherboard_params)
    redirect_to @motherboard, notice: 'Motherboard was successfully updated.'
  else
   render :edit
  end
end

private
def save_attachments
  params[:motherboard_attachments]['photo'].each do |photo|
    @motherboard_attachment = @motherboard.motherboard_attachments.create!(:photo => photo)
  end
end

 def update_attachments
   @motherboard.motherboard_attachments.each(&:destroy) if @motherboard.motherboard_attachments.present?
   params[:motherboard_attachments]['photo'].each do |photo|
     @motherboard_attachment = @motherboard.motherboard_attachments.create!(:photo => photo)
   end
 end

---

下面是我对模型的第二次重构：

将私有方法移动到模型中

用self替换@主板

控制器：

def create
  @motherboard = Motherboard.new(motherboard_params)

  if @motherboard.save
    @motherboard.save_attachments(params) if params[:motherboard_attachments]
  redirect_to @motherboard, notice: 'Motherboard was successfully created.'
  else
    render :new
  end
end

def update
  @motherboard.update_attachments(params) if params[:motherboard_attachments]
  if @motherboard.update(motherboard_params)
    redirect_to @motherboard, notice: 'Motherboard was successfully updated.'
  else
    render :edit
  end
end

@post_attachment = @post.post_attachments.build

在主板型号中：

def save_attachments(params)
  params[:motherboard_attachments]['photo'].each do |photo|
    self.motherboard_attachments.create!(:photo => photo)
  end
end

def update_attachments(params)
  self.motherboard_attachments.each(&:destroy) if self.motherboard_attachments.present?
  params[:motherboard_attachments]['photo'].each do |photo|
    self.motherboard_attachments.create!(:photo => photo)
  end
end

---

如果我们看一下CarrierWave的文档，这实际上很容易

我将使用产品作为模型，我想添加图片，作为一个例子

获取主分支Carrierwave并将其添加到您的GEM文件：

gem 'carrierwave', github:'carrierwaveuploader/carrierwave'

在预期模型中创建一列以承载图像数组：

rails generate migration AddPicturesToProducts pictures:json

运行迁移

bundle exec rake db:migrate

向模型产品添加图片

app/models/product.rb

class Product < ActiveRecord::Base
  validates :name, presence: true
  mount_uploaders :pictures, PictureUploader
end

允许您的表单接受多张图片

app/views/products/new.html.erb

# notice 'html: { multipart: true }'
<%= form_for @product, html: { multipart: true } do |f| %>
  <%= f.label :name %>
  <%= f.text_field :name %>

  # notice 'multiple: true'
  <%= f.label :pictures %>
  <%= f.file_field :pictures, multiple: true, accept: "image/jpeg, image/jpg, image/gif, image/png" %>

  <%= f.submit "Submit" %>
<% end %>

---

如果您从文件夹中选择多个图像，顺序将与您从上到下拍摄图像的顺序完全相同。

SSR的一些小补充回答：

接受的\u嵌套的\u属性\u不需要您更改父对象的控制器。因此，如果要纠正

name: "post_attachments[avatar][]"

到

然后，所有这些控制器更改都变得多余：

params[:post_attachments]['avatar'].each do |a|
  @post_attachment = @post.post_attachments.create!(:avatar => a)
end

此外，还应向父对象窗体添加

PostAttachment.new

：

在views/posts/_form.html.erb中

class Post < ActiveRecord::Base
   has_many :post_attachments
   accepts_nested_attributes_for :post_attachments
end

class PostAttachment < ActiveRecord::Base
   mount_uploader :avatar, AvatarUploader
   belongs_to :post
end

def show
   @post_attachments = @post.post_attachments.all
end

def new
   @post = Post.new
   @post_attachment = @post.post_attachments.build
end

def create
   @post = Post.new(post_params)

   respond_to do |format|
     if @post.save
       params[:post_attachments]['avatar'].each do |a|
          @post_attachment = @post.post_attachments.create!(:avatar => a)
       end
       format.html { redirect_to @post, notice: 'Post was successfully created.' }
     else
       format.html { render action: 'new' }
     end
   end
 end

 private
   def post_params
      params.require(:post).permit(:title, post_attachments_attributes: [:id, :post_id, :avatar])
   end

<%= form_for(@post, :html => { :multipart => true }) do |f| %>
   <div class="field">
     <%= f.label :title %><br>
     <%= f.text_field :title %>
   </div>

   <%= f.fields_for :post_attachments do |p| %>
     <div class="field">
       <%= p.label :avatar %><br>
       <%= p.file_field :avatar, :multiple => true, name: "post_attachments[avatar][]" %>
     </div>
   <% end %>

   <div class="actions">
     <%= f.submit %>
   </div>
<% end %>

<p id="notice"><%= notice %></p>

<p>
  <strong>Title:</strong>
  <%= @post.title %>
</p>

<% @post_attachments.each do |p| %>
  <%= image_tag p.avatar_url %>
  <%= link_to "Edit Attachment", edit_post_attachment_path(p) %>
<% end %>

<%= link_to 'Edit', edit_post_path(@post) %> |
<%= link_to 'Back', posts_path %>

<%= image_tag @post_attachment.avatar %>
<%= form_for(@post_attachment) do |f| %>
  <div class="field">
    <%= f.label :avatar %><br>
    <%= f.file_field :avatar %>
  </div>
  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

def update
  respond_to do |format|
    if @post_attachment.update(post_attachment_params)
      format.html { redirect_to @post_attachment.post, notice: 'Post attachment was successfully updated.' }
    end 
  end
end

  <%= f.fields_for :post_attachments, PostAttachment.new do |ff| %>
    <div class="field">
      <%= ff.label :avatar %><br>
      <%= ff.file_field :avatar, :multiple => true, name: "post[post_attachments_attributes][][avatar]" %>
    </div>
  <% end %>

class Post < ApplicationRecord
    ...
    accepts_nested_attributes_for :post_attachments, allow_destroy: true
end

 <% f.object.post_attachments.each do |post_attachment| %>
    <% if post_attachment.id %>

      <%

      post_attachments_delete_params =
      {
      post:
        {              
          post_attachments_attributes: { id: post_attachment.id, _destroy: true }
        }
      }

      %>

      <%= link_to "Delete", post_path(f.object.id, post_attachments_delete_params), method: :patch, data: { confirm: 'Are you sure?' } %>

      <br><br>
    <% end %>
  <% end %>

有关更多信息，请参阅

如果您使用Rails 5，那么将

Rails.application.config.active\u record.allows\u to\u required\u默认值

值从

true

更改为

false

（在config/initializers/new\u framework\u defaults.rb中），原因是接受嵌套的属性（否则，接受的_嵌套的_属性_通常在Rails 5下不起作用）

编辑1:

要添加关于销毁的内容，请执行以下操作：

在models/post.rb中

class Post < ActiveRecord::Base
   has_many :post_attachments
   accepts_nested_attributes_for :post_attachments
end

class PostAttachment < ActiveRecord::Base
   mount_uploader :avatar, AvatarUploader
   belongs_to :post
end

def show
   @post_attachments = @post.post_attachments.all
end

def new
   @post = Post.new
   @post_attachment = @post.post_attachments.build
end

def create
   @post = Post.new(post_params)

   respond_to do |format|
     if @post.save
       params[:post_attachments]['avatar'].each do |a|
          @post_attachment = @post.post_attachments.create!(:avatar => a)
       end
       format.html { redirect_to @post, notice: 'Post was successfully created.' }
     else
       format.html { render action: 'new' }
     end
   end
 end

 private
   def post_params
      params.require(:post).permit(:title, post_attachments_attributes: [:id, :post_id, :avatar])
   end

<%= form_for(@post, :html => { :multipart => true }) do |f| %>
   <div class="field">
     <%= f.label :title %><br>
     <%= f.text_field :title %>
   </div>

   <%= f.fields_for :post_attachments do |p| %>
     <div class="field">
       <%= p.label :avatar %><br>
       <%= p.file_field :avatar, :multiple => true, name: "post_attachments[avatar][]" %>
     </div>
   <% end %>

   <div class="actions">
     <%= f.submit %>
   </div>
<% end %>

<p id="notice"><%= notice %></p>

<p>
  <strong>Title:</strong>
  <%= @post.title %>
</p>

<% @post_attachments.each do |p| %>
  <%= image_tag p.avatar_url %>
  <%= link_to "Edit Attachment", edit_post_attachment_path(p) %>
<% end %>

<%= link_to 'Edit', edit_post_path(@post) %> |
<%= link_to 'Back', posts_path %>

<%= image_tag @post_attachment.avatar %>
<%= form_for(@post_attachment) do |f| %>
  <div class="field">
    <%= f.label :avatar %><br>
    <%= f.file_field :avatar %>
  </div>
  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

def update
  respond_to do |format|
    if @post_attachment.update(post_attachment_params)
      format.html { redirect_to @post_attachment.post, notice: 'Post attachment was successfully updated.' }
    end 
  end
end

  <%= f.fields_for :post_attachments, PostAttachment.new do |ff| %>
    <div class="field">
      <%= ff.label :avatar %><br>
      <%= ff.file_field :avatar, :multiple => true, name: "post[post_attachments_attributes][][avatar]" %>
    </div>
  <% end %>

class Post < ApplicationRecord
    ...
    accepts_nested_attributes_for :post_attachments, allow_destroy: true
end

 <% f.object.post_attachments.each do |post_attachment| %>
    <% if post_attachment.id %>

      <%

      post_attachments_delete_params =
      {
      post:
        {              
          post_attachments_attributes: { id: post_attachment.id, _destroy: true }
        }
      }

      %>

      <%= link_to "Delete", post_path(f.object.id, post_attachments_delete_params), method: :patch, data: { confirm: 'Are you sure?' } %>

      <br><br>
    <% end %>
  <% end %>

---

这就是为什么

接受

的_嵌套的_属性_如此惊人。

在post控制器的显示操作中，我认为您忘记了@post=post.find（params[：id]）@SSR为什么在

创建
操作中循环浏览每个帖子附件？Rails和carrierwave足够智能，可以自动保存收藏。希望看到编辑（尤其是处理
：_destroy
部分）@SSR-您的答案非常有用。请您也使用编辑操作更新您的答案。当我向post_附件模型添加验证时，它们不会阻止post模型保存。相反，保存了post，然后仅针对附件模型引发ActiveRecord invalid错误。我想这是因为create！方法。但是使用create只是默默地失败了。你知道如何在文章中进行验证吗？谢谢分享你的代码。当你有时间的时候，请在我的gihub repo更新代码，不要忘记对每个方法进行注释，这样每个人都可以很容易地理解代码。我克隆了repo，你能允许我这样做吗PR？是的，当然。你的github用户名是什么？你有机会给我访问权限吗？CarrierWave解决这个问题的方法让我畏缩。它包括将所有对文件的引用放在数组中的一个字段中！当然不会被认为是“rails方式”。如果你想删除一些，或者在帖子中添加额外的文件，那该怎么办？我不是说这不可能，我只是说这会很难看。连接表是一个更好的主意。我完全同意托比。你能提供这样的解决方案吗？SSR已经提供了解决方案。另一个模型已经就位来保存上传的内容文件，那么需要上传多个文件的东西与另一个模型有一对多或多对多的关系。（我在前面的评论中提到的连接表是多对多关系的情况）感谢@Toby1Kenobi，我想知道列数组方法如何解释图像版本（我不知道它是如何实现的）。你的策略是可行的。我已经用Rails 5.x.x实现了Carrierwave的这个功能，但我无法成功运行它，它正在生成错误，
UndefinedConverversionError（“\x89”从ASCII-8BIT到UTF-8）
对于SSR解决方案，它在Rails 4.x.x上运行良好，但我面临着挑战（使用Rails 5.x.x.）即，它在数据库中存储
ActionDispatch:：Http:：UploadedFile
，而不是文件名。它也不在uploader中给定路径的公共文件夹中存储文件。这些实际上是@SSR answer的主要补充，而不是次要补充：）接受\u嵌套的\u属性\u是一件非常重要的事情。实际上根本不需要子控制器。按照您的方法，我唯一不能做的就是