Rails Carrierwave Base64圖像上傳

Question

使用Carrierwave將圖像從客戶端上傳到Rails后端的最佳方法是什么？ 現在我們的iOS開發人員將文件作為base64發送，因此請求如下：

"image_data"=>"/9j/4AAQSkZJRgABAQAAAQABAAD/4QBYRXhpZgAATU0AKgAAAAgAAgESAAMAAAABAAEAAIdpAAQAAAABAAAAJgAAAAAAA6ABAAMAAAABAAEAAKACAAQAAAABAAAAHqADAAQAAAABAAAAHgAAAAD/2wBDAAEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQH/2wBDAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQEBAQH/wAARCAAeAB4DAREAAhEBAxEB/8QAHwAAAQUBAQE....

所以，我的問題實際上是兩個問題。 我應該告訴他發送不同的文件格式嗎？ 如果base64是發送這些文件的正確方法，那么我如何在carrierwave中處理它們？

Answer 1

我認為一種解決方案可以是將解碼后的數據保存到文件中，然后將此文件分配給已安裝的上傳器。 然后擺脫那個文件。

另一個（內存中）解決方案可以是這個：

# define class that extends IO with methods that are required by carrierwave
class CarrierStringIO < StringIO
  def original_filename
    # the real name does not matter
    "photo.jpeg"
  end

  def content_type
    # this should reflect real content type, but for this example it's ok
    "image/jpeg"
  end
end

# some model with carrierwave uploader
class SomeModel
  # the uploader
  mount_uploader :photo, PhotoUploader

  # this method will be called during standard assignment in your controller
  # (like `update_attributes`)
  def image_data=(data)
    # decode data and create stream on them
    io = CarrierStringIO.new(Base64.decode64(data))

    # this will do the thing (photo is mounted carrierwave uploader)
    self.photo = io
  end

end

Answer 2

您可以使用Carrierwave-base64 Gem輕松實現這一點，您無需自己處理數據，只需添加gem並更改模型即可

mount_uploader :file, FileUploader

至

mount_base64_uploader :file, FileUploader

這就是它，現在你可以很容易地說：

Attachment.create(file: params[:file])

Answer 3

老問題但我不得不做類似的事情，從base64字符串上傳圖像，這是通過json請求傳遞的。 這就是我最終做的事情：

#some_controller.rb
def upload_image
  set_resource
  image = get_resource.decode_base64_image params[:image_string]
  begin
    if image && get_resource.update(avatar: image)
      render json: get_resource
    else
      render json: {success: false, message: "Failed to upload image. Please try after some time."}
    end
  ensure
    image.close
    image.unlink
  end
end

#some_model.rb
def decode_base64_image(encoded_file)
  decoded_file = Base64.decode64(encoded_file)
  file = Tempfile.new(['image','.jpg']) 
  file.binmode
  file.write decoded_file

  return file
end