问题描述
我试图建立一个API后端文件上传。我希望能够上传具有该文件的Base64编码字符串的POST请求的文件。服务器应解码字符串，并使用CarrierWave保存文件。这是我到目前为止：photo.rb：
类Photo
包含Mongoid :: Document
包含Mongoid :: Timestamps
mount_uploader：image_file，ImageUploader
end
image_uploader.rb：
class ImageUploader< CarrierWave :: Uploader :: Base
storage：file
def store_dir
uploads /＃{model.class.to_s.underscore} /＃{mounted_as} /＃{model .id}
end
end
Rails控制台：
（summary）
ruby-1.8.7-p334：001> img = File.open（../ image.png）{| i | i.read}
=> \377 JFIF\000\001\002\001\000H\000H\000\000\377 Photoshop3.0\0008BIM\003 ...
ruby-1.8.7-p334：003> encoded_img = Base64.encode64 img
=> 3af8A \\\
mLpplt5U8q + a7G2 ...
ruby-1.8.7-p334：005> p = Photo.new
=>＃< Photo_id：4e21b9a31d41c817b9000001，created_at：nil，updated_at：nil，_type：nil，user_id：nil，image_file_filename：nil>
ruby-1.8.7-p334 ：006> p.user_id = 1
=> 1
ruby-1.8.7-p334：007> p.image_file = Base64.decode64 encoded_img
\255 = \254\2007u\226\230-zhwT\253％\036ʉs\232IsM\215˿6\247\ 256 \177 ...
ruby-1.8.7-p334：008> p.save
=> true
ruby-1.8.7-p334：009> p。 image_file.url
=> nil
这个问题似乎与将Base64解码的字符串转换为文件的过程有关。CarrierWave似乎期望File对象，而是给它一个String。那么如何将该字符串转换为File对象。我希望这种转换不会将任何内容保存到文件系统中，只需创建该对象，然后让CarrierWave完成剩下的工作。
> CarrierWave也接受一个StringIO，但是它需要一个original_filename方法，因为它需要它来计算文件名并进行扩展检查。如何在Rails 2和3之间进行更改，这里有两种方法：
$ b $ Rails 2
$ $ $ $ $ $io = StringIO.new（Base64.decode64（encoded_img））
io.original_filename =foobar.png
p.image_file = io
p .save
在Rails 3中，您需要创建一个新类，然后手动添加 original_filename 返回
class FilelessIO< StringIO
attr_accessor：original_filename
end
$ b $ i = FilelessIO.new（Base64.decode64（encoded_img））
io.original_filename =foobar.png
p.image_file = io
p.save
I'm trying to build an API backend for file uploads. I want to be able to upload files with a POST request that has a Base64-encoded string of the file. The server should decode the string, and save the file using CarrierWave. Here's what I have so far:
photo.rb:
class Photo
include Mongoid::Document
include Mongoid::Timestamps
mount_uploader :image_file, ImageUploader
end
image_uploader.rb:
class ImageUploader < CarrierWave::Uploader::Base
storage :file
def store_dir
"uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"
end
end
Rails console:(summary)
ruby-1.8.7-p334 :001 > img = File.open("../image.png") {|i| i.read}
=> "\377���JFIF\000\001\002\001\000H\000H\000\000\377�Photoshop 3.0\0008BIM\003...
ruby-1.8.7-p334 :003 > encoded_img = Base64.encode64 img
=> 3af8A\nmLpplt5U8q+a7G2...
ruby-1.8.7-p334 :005 > p = Photo.new
=> #<Photo _id: 4e21b9a31d41c817b9000001, created_at: nil, updated_at: nil, _type: nil, user_id: nil, image_file_filename: nil>
ruby-1.8.7-p334 :006 > p.user_id = 1
=> 1
ruby-1.8.7-p334 :007 > p.image_file = Base64.decode64 encoded_img
\255��=\254\200�7u\226���\230�-zh�wT\253%����\036ʉs\232Is�M\215��˿6\247\256\177...
ruby-1.8.7-p334 :008 > p.save
=> true
ruby-1.8.7-p334 :009 > p.image_file.url
=> nil
The problem appears to be related to the process of converting a Base64-decoded string to a file. CarrierWave seems to expect a File object, and instead I'm giving it a String. So how do I convert that String to a File object. I'd like this conversion not to save anything to the file system, simply create the object and let CarrierWave do the rest.
CarrierWave also accepts a StringIO, but it expects a original_filename method, since it needs it for figuring out the file name and doing the extension check. How you do it changed between Rails 2 and 3, here's both methods:
Rails 2
io = StringIO.new(Base64.decode64(encoded_img))
io.original_filename = "foobar.png"
p.image_file = io
p.save
In Rails 3, you need to make a new class and then manually add original_filename back
class FilelessIO < StringIO
attr_accessor :original_filename
end
io = FilelessIO.new(Base64.decode64(encoded_img))
io.original_filename = "foobar.png"
p.image_file = io
p.save
这篇关于使用CarrierWave上传RESTful文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！