Rails 4 使用carrierwave 上传多张图片或文件

本文介绍了Rails 4 使用carrierwave 上传多张图片或文件的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

如何使用 Rails 4 和 CarrierWave 从文件选择窗口上传多个图像?我有一个 post_controller 和 post_attachments 模型.我该怎么做?

谁能举个例子?有没有简单的方法来解决这个问题?

解决方案

这是在rails 4中使用carrierwave从头开始上传多个图像的解决方案

或者你可以找到工作演示:多附件 Rails 4

只需按照以下步骤操作即可.

rails 新的 multiple_image_upload_carrierwave

在 gem 文件中

gem 'carrierwave'捆绑安装rails 生成上传者头像

创建帖子支架

rails 生成脚手架 post title:string

创建 post_attachment 脚手架

rails 生成脚手架 post_attachment post_id:integer avatar:string耙数据库:迁移

在 post.rb

class Post

在 post_attachment.rb 中

class PostAttachment <ActiveRecord::Basemount_uploader :avatar, AvatarUploader归属地:发布结尾

在 post_controller.rb

def 显示@post_attachments = @post.post_attachments.all结尾定义新@post = Post.new@post_attachment = @post.post_attachments.build结尾定义创建@post = Post.new(post_params)response_to do |格式|如果@post.saveparams[:post_attachments]['avatar'].each do |a|@post_attachment = @post.post_attachments.create!(:avatar => a)结尾format.html { redirect_to @post，注意:'帖子已成功创建.'}别的format.html { 渲染动作:'新' }结尾结尾结尾私人的def post_paramsparams.require(:post).permit(:title, post_attachments_attributes: [:id, :post_id, :avatar])结尾

在 views/posts/_form.html.erb

{ :multipart => true }) do |f|％＞<div class="field"><%= f.label :title %><br><%= f.text_field :title %>

<%= f.fields_for :post_attachments do |p|％＞<div class="field"><%= p.label :avatar %><br>真，名称:post_attachments[头像][]"%>

<%结束%><div class="actions"><%= f.submit %>

<%结束%>

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

<p><strong>标题:</strong><%=@post.title%></p><% @post_attachments.each 做 |p|％＞<%= image_tag p.avatar_url %><%= link_to "Edit Attachment", edit_post_attachment_path(p) %><%结束%><%= link_to '编辑', edit_post_path(@post) %>|<%= link_to '返回'，posts_path %>

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

<%= form_for(@post_attachment) 做 |f|％＞<div class="field"><%= f.label :avatar %><br><%= f.file_field :avatar %>

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

<%结束%>

修改post_attachment_controller.rb

中的更新方法

def 更新response_to do |格式|如果@post_attachment.update(post_attachment_params)format.html { redirect_to @post_attachment.post，注意:'帖子附件已成功更新.'}结尾结尾结尾

在 rails 3 中不需要定义强参数，因为您可以在模型和 accept_nested_attribute 中定义 attribute_accessible 以发布模型，因为属性可访问在 rails 4 中已弃用.

对于编辑附件，我们不能一次修改所有附件.所以我们会一一替换附件，或者您可以根据自己的规则进行修改，这里我只告诉您如何更新任何附件.

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?

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

解决方案

This is solution to upload multiple images using carrierwave in rails 4 from scratch

Or you can find working demo : Multiple Attachment Rails 4

To do just follow these steps.

rails new multiple_image_upload_carrierwave

In gem file

gem 'carrierwave' bundle install rails generate uploader Avatar

Create post scaffold

rails generate scaffold post title:string

Create post_attachment scaffold

rails generate scaffold post_attachment post_id:integer avatar:string rake db:migrate

In post.rb

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

In post_attachment.rb

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

In post_controller.rb

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

In 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 %>

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 %>

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 %>

Modify update method in 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

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.

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.