我想在rails中使用rmagick将pdf格式转换为图像格式，然后使用activestorage上传

gem 'rmagick'
gem 'activestorage'

rails generate model PdfFile

class CreatePdfFiles < ActiveRecord::Migration[6.1]
  def change
    create_table :pdf_files do |t|
      t.string :attachment

      t.timestamps
    end
  end
end

rails db:migrate

class PdfFile < ApplicationRecord
  has_one_attached :attachment
end

class PdfFilesController < ApplicationController
  def new
    @pdf_file = PdfFile.new
  end

  def create
    @pdf_file = PdfFile.new(pdf_file_params)
    if @pdf_file.save
      convert_pdf_to_images
      redirect_to @pdf_file, notice: 'PDF file was successfully uploaded and converted.'
    else
      render :new
    end
  end

  private

  def pdf_file_params
    params.require(:pdf_file).permit(:attachment)
  end

  def convert_pdf_to_images
    pdf_path = @pdf_file.attachment.path
    pdf = Magick::ImageList.new(pdf_path)
    pdf.each_with_index do |page, index|
      page.write("#{pdf_path}_#{index}.jpg")
    end
  end
end

<%= form_with(model: @pdf_file, url: pdf_files_path, local: true) do |form| %>
  <%= form.file_field :attachment %>
  <%= form.submit 'Upload and Convert' %>
<% end %>

<h1>Converted Images</h1>
<% @pdf_file.attachment.blobs.each do |blob| %>
  <%= image_tag rails_blob_url(blob) %>
<% end %>

resources :pdf_files, only: [:new, :create, :show]