write stream to paperclip

Question

I want to store received email attachment with usage of paperclip. From email I get part.body and I have no idea how to put it to paperclip'ed model. For now I create temporary file and write port.body to it, store this file to paperclip, and delete file. Here is how I do it with temporary file:

    l_file = File.open(l_path, "w+b", 0644)
    l_file.write(part.body)
    oAsset = Asset.new(
        :email_id => email.id, 
        :asset => l_file, 
        :header => h, 
        :original_file_name => o, 
        :hash => h)
    oAsset.save
    l_file.close
    File.delete(l_path)

:asset is my 'has_attached_file' field. Is there a way to omit file creation and to do something like: :asset => part.body in Asset.new ?

Weekley

Answer 1

This is how I would do it, assuming your using the mail gem to read the email. you'll need the whole email 'part', not just part.body

file = StringIO.new(part.body) #mimic a real upload file
  file.class.class_eval { attr_accessor :original_filename, :content_type } #add attr's that paperclip needs
  file.original_filename = part.filename #assign filename in way that paperclip likes
  file.content_type = part.mime_type # you could set this manually aswell if needed e.g 'application/pdf'

now just use the file object to save to the Paperclip association.

a = Asset.new 
a.asset = file
a.save!

Hope this helps.

Griskin

Thanks! I had to change one line to make your solution work. Correct line is: file = StringIO.open(part.body.to_s) – Weekley

Nice solution. I used this myself but I was concerned about monkey-patching StringIO. See my response below for what I did instead. – Interlocution

This code patches the StringIO class and pollutes any new instances of StringIO. I recommend following gtd's example, because it is safer, by only modifying the one instance of StringIO. It is unfortunate that paperclip doesn't really support StringIO without these modifications. – Ossification

Hoaa, thank you. I'm having this problem since yesterday and now it has been solved. – Hyperbaric

Answer 2

Barlow's answer is good, but it is effectively monkey-patching the StringIO class. In my case I was working with Mechanize::Download#body_io and I didn't want to possibly pollute the class leading to unexpected bugs popping up far away in the app. So I define the methods on the instances metaclass like so:

original_filename = "whatever.pdf" # Set local variables for the closure below
content_type = "application/pdf"

file = StringIO.new(part.body)

metaclass = class << file; self; end
metaclass.class_eval do
  define_method(:original_filename) { original_filename }
  define_method(:content_type) { content_type }
end

Interlocution

Answer 3

I like gtd's answer a lot, but it can be simpler.

file = StringIO.new(part.body)

class << file
  define_method(:original_filename) { "whatever.pdf" }
  define_method(:content_type) { "application/pdf" }
end

There's not really a need to extract the "metaclass" into a local variable, just append some class to the object.

Dravidian

You can also just create a new class for this. class FileString < StringIO; attr_accessor :original_filename, :content_type; end – Wimberly

Answer 4

From ruby 1.9, you can use StringIO and define_singleton_method :

def attachment_from_string(string, original_filename, content_type)
  StringIO.new(string).tap do |file|
    file.define_singleton_method(:original_filename) { original_filename }
    file.define_singleton_method(:content_type) { content_type }
  end
end

Flowerpot

Answer 5

This would have been better as a comment on David-Barlow's answer but I don't have enough reputation points yet...

But, as others mentioned I didn't love the monkey-patching. Instead, I just created a new class that inherited from StringIO, like so:

class TempFile < StringIO
  attr_accessor :original_filename, :content_type  
end

Penny

Answer 6

For posterity, here is the best answer. Put the top part in vendor/paperclip/data_uri_adapter.rb and the bottom part in config/initializers/paperclip.rb.

https://github.com/thoughtbot/paperclip/blob/43eb9a36deb09ce5655028a1061578dbf0268a5d/lib/paperclip/io_adapters/data_uri_adapter.rb

This requires a data URI scheme stream, but these days that seems pretty common. Simply set your paperclip'd variable to a string with the stream data, and the code takes care of the rest.

Snigger

Answer 7

I used a similar technique to pull down images into paperclip

this should work, but is obvs untested:

io = part.body
def io.original_filename; part.original_file_name || 'unknown-file-name'; end

asset = Asset.new(:email=>email)
asset.asset = io

When we are assigning the IO directly to the paperclip instance, it needs to have a .original_file_name to it, so that's what we're doing in the second line.

Cornemuse

Doesn't seem to work :( even if I give :asset_file_name explicitly there is no file being created. – Weekley

OK, you'll need to get part.body into an IO stream. try reading it. good luck! – Cornemuse