使用Paperclip Rails 4多个文件附件

Question

我知道Stackoverflow上有几篇帖子和几个关于这个主题的教程。然而，他们都没有设法解决我的问题，其中大多数也已经过时了。

我正在尝试使用Rails 4中的paperclip gem将多个图像添加到项目中。 当我尝试上传它时，我确实看到附加在params中的资产。

虽然它们似乎没有被添加到project_paramns中。

希望有人可以帮助我。

这是我的projects_controller

class ProjectsController < ApplicationController

  before_filter :find_project, only: [:show, :edit, :update, :destroy]

  def index
   @projects = Project.all
  end

  def show
  end

  def new
    @project = Project.new
  end

  def create
    @project = Project.new(project_params)
    @project.save

    redirect_to project_path(@project)
  end

  def edit
  end

  def update
    @project.update(project_params)

    redirect_to project_path(@project)
  end

  def destroy
    @project.destroy

    redirect_to projects_path
  end

  protected

    def project_params
      params.require(:project).permit(:name, :description, :asset)
    end

    def find_project
      @project = Project.find(params[:id])
    end
end

我的项目模型

class Project < ActiveRecord::Base
  has_many :assets, :dependent => :destroy

  validates_associated :assets
  validates_presence_of :name, :on => :create, :update => "can't be blank"
  validates_presence_of :description, :on => :create, :update => "can't be blank"

  accepts_nested_attributes_for :assets
end

我的资产模型

class Asset < ActiveRecord::Base
    belongs_to :project

  # Paperclip
  has_attached_file :image,
    :styles => {
      :thumb=> "100x100#",
      :small  => "150x150>",
      :medium => "300x300>",
      :large =>   "400x400>" }
  validates_attachment :image, content_type: { content_type: ["image/jpg", "image/jpeg",     "image/png", "image/gif"] }
end

我的表格部分（抱歉是在HAML中）

= simple_form_for @project do |f|
  %ul
    - @project.errors.full_messages.each do |error|
      %li= error
  .row
    .small-1.columns    
      = f.label :name, :class => "left inline"
    .small-11.columns
      = f.input_field :name
  .row
    .small-1.columns
      = f.label :description, :class => "left inline"
    .small-11.columns 
      = f.input_field :description, as: :text
  .row
    = f.simple_fields_for :asset do |a|
      .small-1.columns
        = a.label :image, :class => "left inline"
      .small-11.columns
        = file_field_tag :image, multiple: true,
  .row
    .small-9.small-offset-1.columns
      = f.submit nil ,:class => "button [radius round]"

请求参数

{"utf8"=>"✓", "_method"=>"patch", "authenticity_token"=>"4iK1kUNvKvoJVOKoivz/pcLAe6LY0cUJikQioxa8BIs=", "project"=>{"name"=>"adf", "description"=>"adf", "asset"=>{"image"=>[#<ActionDispatch::Http::UploadedFile:0x007fb808357d80 @tempfile=#<Tempfile:/var/folders/v_/98sxm8bn24qbqj_jmj40fv400000gn/T/RackMultipart20140607-34739-dvlzt7>, @original_filename="enabling-gzip-compression.jpg", @content_type="image/jpeg", @headers="Content-Disposition: form-data; name=\"project[asset][image][]\"; filename=\"enabling-gzip-compression.jpg\"\r\nContent-Type: image/jpeg\r\n">, #<ActionDispatch::Http::UploadedFile:0x007fb808357d58 @tempfile=#<Tempfile:/var/folders/v_/98sxm8bn24qbqj_jmj40fv400000gn/T/RackMultipart20140607-34739-lwkioi>, @original_filename="minimize_http_requests.png", @content_type="image/png", @headers="Content-Disposition: form-data; name=\"project[asset][image][]\"; filename=\"minimize_http_requests.png\"\r\nContent-Type: image/png\r\n">]}}, "commit"=>"Update Project", "action"=>"update", "controller"=>"projects", "id"=>"11"}

现在我的终端出现了错误：

Unpermitted parameters: asset

修改

@ pavan和@kiri thorat的答案的组合帮助我在project_params中显示了一些内容，它现在提供的输出是：

{"name"=>"Test", "description"=>"Test", "assets_attributes"=>{"0"=>{}}}

关于这里发生了什么的任何线索？

在@ kirithorat的最新更新之后，事情的参数方面似乎很好。

{"utf8"=>"✓", "_method"=>"patch", "authenticity_token"=>"4iK1kUNvKvoJVOKoivz/pcLAe6LY0cUJikQioxa8BIs=", "project"=>{"name"=>"Test", "description"=>"Test", "assets_attributes"=>{"0"=>{"image"=>#<ActionDispatch::Http::UploadedFile:0x007fcd383c9a08 @tempfile=#<Tempfile:/var/folders/v_/98sxm8bn24qbqj_jmj40fv400000gn/T/RackMultipart20140610-36517-7ek1oq>, @original_filename="enabling-gzip-compression.jpg", @content_type="image/jpeg", @headers="Content-Disposition: form-data; name=\"project[assets_attributes][0][image]\"; filename=\"enabling-gzip-compression.jpg\"\r\nContent-Type: image/jpeg\r\n">}}}, "commit"=>"Update Project", "action"=>"update", "controller"=>"projects", "id"=>"13"}

但资产仍然没有被保存。

实施@ Valikiliy的建议后更新

{"utf8"=>"✓", "_method"=>"patch", "authenticity_token"=>"4iK1kUNvKvoJVOKoivz/pcLAe6LY0cUJikQioxa8BIs=", "project"=>{"name"=>"Test", "description"=>"Test", "image"=>#<ActionDispatch::Http::UploadedFile:0x007fcd3a08d0b8 @tempfile=#<Tempfile:/var/folders/v_/98sxm8bn24qbqj_jmj40fv400000gn/T/RackMultipart20140610-36517-rgy95n>, @original_filename="minimize_http_requests.png", @content_type="image/png", @headers="Content-Disposition: form-data; name=\"project[image]\"; filename=\"minimize_http_requests.png\"\r\nContent-Type: image/png\r\n">}, "commit"=>"Update Project", "action"=>"update", "controller"=>"projects", "id"=>"16"}

更新：根据要求添加了新的表单代码

= simple_form_for(@project, :html => { :multipart => true }) do |f|
  %ul
    - @project.errors.full_messages.each do |error|
      %li= error
  .row
    .small-1.columns    
      = f.label :name, :class => "left inline"
    .small-11.columns
      = f.text_field :name
  .row
    .small-1.columns
      = f.label :description, :class => "left inline"
    .small-11.columns 
      = f.text_area :description
  .row
    = f.simple_fields_for :assets do |a|
      .small-1.columns
        = a.label :image, :class => "left inline"
      .small-11.columns
        - if a.object.new_record?
          = a.input :image, as: :file
        - else
          = image_tag a.object.image.url(:thumb)
          = a.input_field '_destroy', as: :boolean
  .row
    .small-9.small-offset-1.columns
      = f.submit nil ,:class => "button [radius round]"

更新

def project_params
  params.require(:project).permit(:name, :description, images: [], assets_attributes: [:_destroy, :id, :image])
end

def find_project
  @project = Project.find(params[:id])
  @project.assets.build if %w[new edit].include?(action_name) 
end

更新：添加了型号代码

class Project < ActiveRecord::Base
  has_many :assets, :dependent => :destroy

  validates_presence_of :name, :on => :create, :update => "can't be blank"
  validates_presence_of :description, :on => :create, :update => "can't be blank"

  accepts_nested_attributes_for :assets, :reject_if => lambda { |a| a[:content].blank? }, :allow_destroy => true
end

Answer 1

要保存上述示例中的多个文件，您不需要添加 multiple：true 选项，保存时会出错，一个文件 - 一个记录资产表。

要解决此问题，您可以添加多个文件字段，如下所示： 加入控制器：

def new
  @project = Project.new
  3.times{ @project.assets.build } 
end

def edit
  3.times{ @project.assets.build } 
end

for while list

.permit(..., assets_attributes: [ :_destroy, :id, :image ])

并且像这样：

= f.simple_fields_for :assets do |a|
  .small-1.columns
    = a.label :image, :class => "left inline"
    - if a.object.new_record?
      .small-11.columns
        = a.file_field :image
    - else
      .small-11.columns
        = image_tag a.object.image.url(:thumb)
        = a.input_field '_destroy', as: :boolean

如果你尝试发送这样的多个图像：

# view
a.file_field :image, multiple: true

# controller
.permit(..., assets_attributes: [ :_destroy, :id, image: [] ])

这会导致错误，因为Asset模型不知道如何处理图像数组。

要同时保存多个文件，您需要使用自己的处理程序，例如：

模型：添加images=方法

def images=(files = [])
  assets.create(image: f)
end

controller：将images: []移到assets_attributes

之外

.permit(..., images: [], assets_attributes: [ :_destroy, :id ])

view：删除fields_for和嵌套属性

  .row
    .small-1.columns
      =f.file_field :images, multiple: true
  .row
    = f.simple_fields_for :assets do |a|
      .small-1.columns
        = a.label :image, :class => "left inline"
....

Answer 2

project_params 应该是这样的

def project_params
  params.require(:project).permit(:name, :description, assets_attributes: [:image])
end

此外，为什么您使用 protected ？我想你应该使用 private 。

Answer 3

Project和Asset型号之间存在1-M关系，即

项目has_many资产

因此，在您的表单中，部分simple_fields_for应该看起来像

= f.simple_fields_for :assets do |a| 

注意 assets 复数而非asset 单数

在您当前的代码中，您使用simple_fields_for与单数 asset这就是为什么params生成错误并且您收到asset密钥的原因在params哈希中，而不是接收assets_attributes密钥，导致警告为Unpermitted parameters: asset。

一旦您更正了表单部分，您将在表单提交时收到params哈希中的正确密钥。现在，正如@Pavan指出我看到的下一个问题是你没有在控制器中正确地允许assets_attributes。

您需要更新project_params方法，如下所示：

def project_params
  params.require(:project).permit(:name, :description, assets_attributes: [:image])
end

注意 assets_attributes 复数中的assets

<强>更新

您需要在@project.assets.build的{​​{1}}和new操作中添加edit，才能在ProjectsController和{{{{}}中查看资源字段1}}查看。 另外，我建议在new中edit的允许属性列表中添加:id，如下所示：

assets_attributes

我看到的project_params中出现的问题很少

1. 在上传文件时，您应在表单中指定 params.require(:project).permit(:name, :description, assets_attributes: [:id, :image]) 。

   更改

   form partial

   要

   :html => {:multipart => true}

2. 项目has_many资产，每个= simple_form_for @project do |f| 记录只有一个= simple_form_for @project, :html => {:multipart => true} do |f| ，因此请删除asset。另外，在使用image时，建议使用multiple: true辅助方法上传文件。

   更改

   simple_form

   要

   simple_form