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.

它们似乎没有添加到project_paramns但是..

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

我的形式部分(抱歉,它在HAML)

= 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

编辑:

@ 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

要在上面的例子中保存多个文件,不需要添加multiple:true选项,它会在保存时导致错误,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:add into controller:

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

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

对于列表

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

并在这样看来:

= 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

如果您尝试发送多个这样的图像:

# view
a.file_field :image, multiple: true

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

这将导致错误,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:

model:添加images=方法

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

controller:移出images: []assets_attributes

.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"
....