Question

我有很大麻烦...

我已经通过我的Rails应用程序将大约500张图像上传到S3，有几种不同的尺寸。现在我意识到我需要将这些图像尺寸存储到我的数据库中。我这样做的方法是进行迁移：

class AddImageDimensionsToImages < ActiveRecord::Migration
  def change

    # add image columns
    add_column :images, :small_width, :integer
    add_column :images, :small_height, :integer
    add_column :images, :medium_width, :integer
    add_column :images, :medium_height, :integer
    add_column :images, :large_width, :integer
    add_column :images, :large_height, :integer
    add_column :images, :original_width, :integer
    add_column :images, :original_height, :integer

    # loop all images
    Image.all.each do |image|

      # get sizes
      geo_small = Paperclip::Geometry.from_file(image.image.to_file(:small))
      geo_medium = Paperclip::Geometry.from_file(image.image.to_file(:medium))
      geo_large = Paperclip::Geometry.from_file(image.image.to_file(:large))
      geo_original = Paperclip::Geometry.from_file(image.image.to_file(:original))

      # set sizes
      image.small_width = geo_small.width if geo_small
      image.small_height = geo_small.height if geo_small

      image.medium_width = geo_medium.width if geo_medium
      image.medium_height = geo_medium.height if geo_medium

      image.large_width = geo_large.width if geo_large
      image.large_height = geo_large.height if geo_large

      image.original_width = geo_original.width if geo_original
      image.original_height = geo_original.height if geo_original

      # save image
      image.save

    end

  end

end

当我运行此迁移时，它会像这样：

...

-- add_column(:images, :small_width, :integer)
   -> 2.0866s
-- add_column(:images, :small_height, :integer)
   -> 0.0092s
-- add_column(:images, :medium_width, :integer)
   -> 0.0073s

...

Command :: identify -format %wx%h '/app/tmp/HayUnFinal_1620120408-4-qpzyym.jpg[0]'
[AWS S3 200 0.106467] get_object(:bucket_name=>"aa",:key=>"original/34/HayUnFinal_16.jpg")

Command :: identify -format %wx%h '/app/tmp/HayUnFinal_1620120408-4-1vqo71y.jpg[0]'
[paperclip] Saving attachments.
[AWS S3 200 0.152898] get_object(:bucket_name=>"aa",:key=>"small/64/Portrait_2.jpg")

Command :: identify -format %wx%h '/app/tmp/Portrait_220120408-4-i1ohlr.jpg[0]'
[AWS S3 200 0.055378] get_object(:bucket_name=>"aa",:key=>"medium/64/Portrait_2.jpg")

Command :: identify -format %wx%h '/app/tmp/Portrait_220120408-4-viizzf.jpg[0]'
[AWS S3 200 0.079235] get_object(:bucket_name=>"aa",:key=>"large/64/Portrait_2.jpg")

Command :: identify -format %wx%h '/app/tmp/Portrait_220120408-4-1d2u00o.jpg[0]'
[AWS S3 200 0.066724] get_object(:bucket_name=>"aa",:key=>"original/64/Portrait_2.jpg")

Command :: identify -format %wx%h '/app/tmp/Portrait_220120408-4-jq9wmg.jpg[0]'
[paperclip] Saving attachments.
[AWS S3 200 0.104891] get_object(:bucket_name=>"aa",:key=>"small/58/Bansah_24.jpg")

Command :: identify -format %wx%h '/app/tmp/Bansah_2420120408-4-an2mpt.jpg[0]'
[AWS S3 200 0.064148] get_object(:bucket_name=>"aa",:key=>"medium/58/Bansah_24.jpg")

Command :: identify -format %wx%h '/app/tmp/Bansah_2420120408-4-tzmnup.jpg[0]'
[AWS S3 200 0.051090] get_object(:bucket_name=>"aa",:key=>"large/58/Bansah_24.jpg")

Command :: identify -format %wx%h '/app/tmp/Bansah_2420120408-4-1pa0rxh.jpg[0]'
[AWS S3 200 0.063531] get_object(:bucket_name=>"aa",:key=>"original/58/Bansah_24.jpg")

Command :: identify -format %wx%h '/app/tmp/Bansah_2420120408-4-kogk2g.jpg[0]'
[paperclip] Saving attachments.

rake aborted!
An error has occurred, this and all later migrations canceled:

can't convert nil into String

耙子流产了！它似乎适用于几个图像，但随后迁移失败。我无法弄清楚那些来自哪里，以及如何防止它。任何人都可以帮我这个吗？

红利问题：这是否是一种保留已保存已上传图片图像尺寸的重要方法？

提前多多感谢！

Answer 1

数据库中的某些图像行具有空图像值。像这样的支票就成了诀窍：

Image.all.each do |image|

  # check that we have an image
  if image.image_file_size

    ...

  end

end

回形针 - 将图像尺寸从已上载的图像保存到数据库

1 个答案: