Saving a profile image fetched from Facebook while using the Paperclip gem - ruby-on-rails

Question

I'm trying to figure out how to let a user upload a photo from their computer or fetch it from Facebook.
I already have a form for uploading an image and saving it using the Paperclip plugin. That works fine.
I've also already set up Facebook authentication and am using the Koala gem to access the Facebook graph API.
I've already wrote this method:
def fetch_fb_picture
unless current_user.authentications.blank?
#graph = Koala::Facebook::GraphAPI.new(current_user.authentications.find_by_provider("facebook").token)
#picture = #graph.get_picture("#{current_user.authentications.find_by_provider('facebook').username}")
current_user.profile.photo = #picture
end
end
I believe the Koala gem returns the url of the image. However, since I'm using the paperclip gem, my profile accepts these attributes:
t.string "photo_file_name"
t.string "photo_content_type"
t.integer "photo_file_size"
How do I, therefore, properly save the facebook image into the database?

Answer 1

You can do something like:
r = open("http://graph.facebook.com/#{#user.facebook_id}/picture")
image_data = r.read
file_size = r.length
mime_type = "image/jpeg" #fb photos always are jpg
#write data to database, or save as temp file and upload to S3
I wouldnt suggest doing it this way, as the Faceboook graph will always return you the image of the user, as they are always publicly available. You just need to call /picture after their ID or username. You could have a boolean to see if it is a facebook user, and just use the ID to display the image. This will also ensure you have the most recent Facebook photo.
if #user.facebook_image?
image_tag "http://graph.facebook.com/#{#user.facebook_id}/picture"
else
image_tag #user.photo.url(:thumb)
end

Answer 2

I was searching about geting a FB profile pic and saving it with rails to s3, I found a way based on the previous answer (using rmagick):
r = open("http://graph.facebook.com/"+params[:FacebookId]+"/picture?width=142&height=142")
bytes = r.read
img = Magick::Image.from_blob(bytes).first
fmt = img.format
data=StringIO.new(bytes)
data.class.class_eval { attr_accessor :original_filename, :content_type }
data.original_filename = Time.now.to_i.to_s+"."+fmt
data.content_type='image.jpeg'
user.profilepic = data
user.save