Rails 4使用carrierwave上传多个图像或文件 [英] Rails 4 multiple image or file upload using carrierwave

问题描述

如何使用Rails 4和CarrierWave从文件选择窗口上传多张图像？我有一个 post_controller 和 post_attachments 模型。我该怎么办？

How can I upload multiple images from a file selection window using Rails 4 and CarrierWave? I have a post_controller and post_attachments model. How can I do this?

有人可以提供示例吗？有简单的方法吗？

Can someone provide an example? Is there a simple approach to this?

推荐答案

这是上传多个图像的解决方案从头开始使用Rails 4中的载波

或者您可以找到有效的演示：
多重连接滑轨4

Or you can find working demo : Multiple Attachment Rails 4

只需按照以下步骤操作即可。

rails new multiple_image_upload_carrierwave

在gem文件中

gem 'carrierwave'
bundle install
rails generate uploader Avatar 

创建帖子支架

rails generate scaffold post title:string

创建附件后支架

rails generate scaffold post_attachment post_id:integer avatar:string

rake db:migrate

在post.rb

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

在post_attachment.rb

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

在post_controller.rb中

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

在views / posts / _form.html.erb

<%= 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 %>

编辑任何帖子的附件和附件列表。
在views / posts / show.html.erb

To edit an attachment and list of attachment for any post. In views/posts/show.html.erb

<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 %>

更新表单以编辑附件 views / post_attachments / _form.html.erb >

Update form to edit an attachment views/post_attachments/_form.html.erb

<%= 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 %>

在 post_attachment_controller.rb

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

在Rails 3中无需定义强参数，并且您可以在两个模型中定义attribute_accessible并接受post_model属性，因为在rails 4中已弃用了可访问的属性。

In rails 3 no need to define strong parameters and as you can define attribute_accessible in both the model and accept_nested_attribute to post model because attribute accessible is deprecated in rails 4.

对于编辑附件，我们无法一次修改所有附件。因此我们将一一替换附件，或者您可以根据自己的规则进行修改。在这里，我仅向您展示如何更新任何附件。

For edit an attachment we cant modify all the attachments at a time. so we will replace attachment one by one, or you can modify as per your rule, Here I just show you how to update any attachment.

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