Ruby Rails回形针-在另一个字段中复制附件文件名

我有下表：

create_table "documents", force: true do |t|
  t.string   "title"
  t.integer  "subject_id"
  t.datetime "created_at"
  t.datetime "updated_at"
  t.string   "attachment_file_name"
  t.string   "attachment_content_type"
  t.integer  "attachment_file_size"
  t.datetime "attachment_updated_at"
end

每当我使用回形针上传文件时，我都想将“附件文件名”的参数复制到“标题”

这个应用程序是一个API，但我正在使用一个debugs\u控制器来测试它

调试控制器

class DebugsController < ApplicationController
   def index
    @document = Document.new
    @documents = Document.all
    @subject = Subject.new
  end
end

class DocumentsController < ApplicationController
  before_action :set_document, only: [:show, :update, :destroy]
  skip_before_action :verify_authenticity_token

  respond_to :json

  def index
    @documents = Document.all
  end

  def new
    @document = Document.new
    @documents = Document.all
  end

  def show
  end

  def create
    @document = Document.new(document_params)
    @document.title = params[:attachment].original_filename

    if @document.save
      respond_with(@document, status: :created)

    else
      respond_with(@document, status: 403)
    end
  end

  def update
   if @document.update(document_params)
      respond_with(@document)
    else
      respond_with(@document.errors, status: :unprocessable_entity)
    end
  end

  def destroy
    @document.destroy
    respond_with(@document, status: :destroyed)
  end

  private

  def set_document
    @document = Document.find(params[:id])
  end

  def document_params
    params.require(:document).permit(:title, :attachment, :subject_id)
  end
end

调试/index.html.erb

<form action="http://0.0.0.0:3000/documents" method="POST" enctype="multipart/form-data">
  <input name="document[title]" type="text" placeholder="doc naam">
  <input name='document[attachment]' type="file">
  <input name="document[subject_id]" type="text" placeholder="Subject id">
  <input type="submit">
</form>

文档控制器

class DebugsController < ApplicationController
   def index
    @document = Document.new
    @documents = Document.all
    @subject = Subject.new
  end
end

class DocumentsController < ApplicationController
  before_action :set_document, only: [:show, :update, :destroy]
  skip_before_action :verify_authenticity_token

  respond_to :json

  def index
    @documents = Document.all
  end

  def new
    @document = Document.new
    @documents = Document.all
  end

  def show
  end

  def create
    @document = Document.new(document_params)
    @document.title = params[:attachment].original_filename

    if @document.save
      respond_with(@document, status: :created)

    else
      respond_with(@document, status: 403)
    end
  end

  def update
   if @document.update(document_params)
      respond_with(@document)
    else
      respond_with(@document.errors, status: :unprocessable_entity)
    end
  end

  def destroy
    @document.destroy
    respond_with(@document, status: :destroyed)
  end

  private

  def set_document
    @document = Document.find(params[:id])
  end

  def document_params
    params.require(:document).permit(:title, :attachment, :subject_id)
  end
end

Document.rb

class Document < ActiveRecord::Base
  belongs_to :subject
  has_many :notes
  has_attached_file :attachment, url: '/system/:attachment/:id_partition/:basename.:extension'

  validates_attachment :attachment, presence: {
    message: 'You have to upload a file!' }, content_type: {
      content_type: %w( application/pdf ), message: 'PDF files only.' }, size: {
        in: 0..10.megabytes, message: 'The maximum file-size is 10MB.' }

  validates :subject_id, presence: { message: 'Assign your document to a case!' }
end

这将为我输出“nil:NilClass”的未定义方法“original_filename”

参数：

 {"document"=>{"title"=>"",
 "attachment"=>#<ActionDispatch::Http::UploadedFile:0x007fbcea87c518 @tempfile=#<Tempfile:/var/folders/sy/9v_t59x974qg_m2nvmcyvkjr0000gn/T/RackMultipart20141202-14285-z5aj46>,
 @original_filename="Teamsweet.pdf",
 @content_type="application/pdf",
 @headers="Content-Disposition: form-data; name=\"document[attachment]\"; filename=\"Teamsweet.pdf\"\r\nContent-Type: application/pdf\r\n">,
 "subject_id"=>"1"},
 "format"=>:json}

---

有人知道如何将“附件文件名”的内容复制到文档的“标题”字段中吗？而且在复制文件名的过程中，是否可以删除上载文件的扩展名？

您可以在模型中而不是在控制器中执行此操作

class Document < ActiveRecord::Base
  before_save :set_title

  def set_title
    self.title = self.attachment_file_name
  end

  ...
end

---

这帮我找到了正确的方向。我最终使用了“before_create”，因此仅用于新对象的创建操作，这样我就可以在保存文档后将标题更新为其他内容。附件\u文件\u名称中的“self”不是必需的。非常感谢。您可以使用ruby alias attributes方法进行分配：