我如何使用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?
有人可以提供一个例子吗? 是否有简单的方法来完成这个任务?
我如何使用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?
有人可以提供一个例子吗? 是否有简单的方法来完成这个任务?
rails new multiple_image_upload_carrierwave
gem 'carrierwave'
bundle install
rails generate uploader Avatar
创建文章脚手架
rails generate scaffold post title:string
创建 post_attachment 脚手架
rails generate scaffold post_attachment post_id:integer avatar:string
rake db:migrate
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 %>
编辑任何帖子的附件和附件列表。 在views/posts/show.html.erb中
<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
<%= 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 %>
修改 post_attachment_controller.rb 中的更新方法。
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
gem 'carrierwave', github:'carrierwaveuploader/carrierwave'
在目标模型中创建一个列来存储图像数组:
rails generate migration AddPicturesToProducts pictures:json
运行数据迁移
bundle exec rake db:migrate
向产品模型添加图片
app/models/product.rb
class Product < ActiveRecord::Base
validates :name, presence: true
mount_uploaders :pictures, PictureUploader
end
在ProductsController中的强参数(Strong Params)中添加图片
app/controllers/products_controller.rb
def product_params
params.require(:product).permit(:name, pictures: [])
end
允许您的表单接受多张照片
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 %>
在您的观点中,您可以引用解析图片数组的图像:
@product.pictures[1].url
如果您从一个文件夹中选择了多张图片,它们的顺序将按照您从上到下选择的确切顺序排列。
如果您从一个文件夹中选择了多张图片,它们的顺序将按照您从上到下选择的确切顺序排列。
UndefinedConversionError ("\x89" from ASCII-8BIT to UTF-8)
对于SSR解决方案,在Rails 4.x.x下可以正常工作,但在Rails 5.x.x下出现了挑战。例如,它将 ActionDispatch::Http::UploadedFile
存储在数据库中而不是文件名。同时也没有将文件存储在上传器指定路径的公共文件夹中。 - Mansi Shahname: "post_attachments[avatar][]"
为了
name: "post[post_attachments_attributes][][avatar]"
那么所有这些控制器的更改都变得多余:
params[:post_attachments]['avatar'].each do |a|
@post_attachment = @post.post_attachments.create!(:avatar => a)
end
您还应将PostAttachment.new
添加到父对象表单中:
在views/posts/_form.html.erb文件中
<%= 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 %>
@post_attachment = @post.post_attachments.build
了解更多信息,请参见Rails fields_for表单未显示,嵌套表单
如果您使用的是Rails 5,则将Rails.application.config.active_record.belongs_to_required_by_default
值从true
更改为false
(在config / initializers / new_framework_defaults.rb中),由于accepts_nested_attributes_for内部存在错误(否则accepts_nested_attributes_for通常不起作用在Rails 5下)。
编辑1:
关于destroy的添加:
在models / post.rb中
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 %>
这样,您根本不需要拥有子对象的控制器!我的意思是不再需要任何PostAttachmentsController
了。至于父对象的控制器(PostController
),您也几乎不需要更改它 - 您所做的唯一更改就是在其中更改白名单参数列表(以包括与子对象相关的参数),如下所示:
def post_params
params.require(:post).permit(:title, :text,
post_attachments_attributes: ["avatar", "@original_filename", "@content_type", "@headers", "_destroy", "id"])
end
accepts_nested_attributes_for
如此神奇。<%= d.text_field :copyright, name: "album[diapos_attributes][][copyright]", class: 'form-field' %>
只将版权写入最后一条记录,而不是所有记录。 - SEJU我还想告诉你,我找到了一种更新多文件上传的方法,并对其进行了一些重构。这段代码是我的,但你应该明白我的意思。
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
使用关联 @post.post_attachments
时,无需设置 post_id
。
这是我对模型进行的第二次重构:
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
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
create
动作中要循环遍历每个帖子附件?Rails 和 carrierwave 已经足够智能,可以自动保存集合。 - hawk:_destroy
部分)。 - Tun