respond_to 和服务对象

Question

我目前正在使用 docx_replace gem 将数据自动插入到一组文档中。 gem 非常简单；基本上它在你的 rails 控制器中以一种特殊的方法运行，就像这样（从文档中引用）：

def user_report
  @user = User.find(params[:user_id])

  respond_to do |format|
    format.docx do
      # Initialize DocxReplace with your template
      doc = DocxReplace::Doc.new("#{Rails.root}/lib/docx_templates/my_template.docx", "#{Rails.root}/tmp")

      # Replace some variables. $var$ convention is used here, but not required.
      doc.replace("$first_name$", @user.first_name)
      doc.replace("$last_name$", @user.last_name)
      doc.replace("$user_bio$", @user.bio)

      # Write the document back to a temporary file
      tmp_file = Tempfile.new('word_tempate', "#{Rails.root}/tmp")
      doc.commit(tmp_file.path)

      # Respond to the request by sending the temp file
      send_file tmp_file.path, filename: "user_#{@user.id}_report.docx", disposition: 'attachment'
    end
  end
end

然而，这使我的控制器变得臃肿，所以我尝试将其放入服务对象中（继续上面的示例）：

class UserReportService
    def initialize(user)
        @user=user
    end

    def user_report_generate
        respond_to do |format|
            format.docx do
                # Initialize DocxReplace with your template
                doc = DocxReplace::Doc.new("#{Rails.root}/lib/docx_templates/my_template.docx", "#{Rails.root}/tmp")

                # Replace some variables. $var$ convention is used here, but not required.
                doc.replace("$first_name$", @user.first_name)
                doc.replace("$last_name$", @user.last_name)
                doc.replace("$user_bio$", @user.bio)

                # Write the document back to a temporary file
                tmp_file = Tempfile.new('word_tempate', "#{Rails.root}/tmp")
                doc.commit(tmp_file.path)

                # Respond to the request by sending the temp file
                send_file tmp_file.path, filename: "user_#{@user.id}_report.docx", disposition: 'attachment'
            end
        end
    end
end

并在我的控制器中完成了以下操作：

def user_report
  UserReportService.new(@user).user_report_generate
end

但是当我调用控制器方法时，出现以下错误：

17:58:10 web.1  | NoMethodError (undefined method `respond_to' for #<UserReportService:0x000000041e5ab0>):
17:58:10 web.1  |   app/services/user_report_service.rb:17:in `user_report_generate'
17:58:10 web.1  |   app/controllers/user_controller.rb:77:in `user_report'

我仔细阅读了 respond_to，如果我对文档的理解正确的话，它是一种特定于控制器的方法（这可以解释问题）。我怎样才能解决这个问题？

Answer 1

respond_to 和 send_file 应该保留在您的控制器中，但其余逻辑可以移至服务对象中。

首先，使服务对象return成为temp_file:

class UserReportService
  def initialize(user)
    @user=user
  end

  def user_report_generate
    # Initialize DocxReplace with your template
    doc = DocxReplace::Doc.new("#{Rails.root}/lib/docx_templates/my_template.docx", "#{Rails.root}/tmp")

    # Replace some variables. $var$ convention is used here, but not required.
    doc.replace("$first_name$", @user.first_name)
    doc.replace("$last_name$", @user.last_name)
    doc.replace("$user_bio$", @user.bio)

    # Write the document back to a temporary file
    tmp_file = Tempfile.new('word_tempate', "#{Rails.root}/tmp")
    doc.commit(tmp_file.path)

    # Return the tmp_file
    tmp_file
  end
end

实例化您的服务对象，检索临时文件，并将其发送给用户：

def user_report
  respond_to do |format|
    format.docx do
      tmp_file = UserReportService.new(@user).user_report_generate
      send_file tmp_file.path, filename: "user_#{@user.id}_report.docx", disposition: 'attachment'
    end
  end
end

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