Tracing Ruby Gmail Gem Methods Back To Their Origins - ruby

Question

My goal is to find the place where save_attachments_to is called in this gmail gem readme example:
folder = "/where/ever"
gmail.mailbox("Faxes").emails do |email|
if !email.message.attachments.empty?
email.message.save_attachments_to(folder)
end
end
I run a "puts email.message.attachments.methods and a "email.message.attachments.class" in the loop:
Mail::AttachmentsList
guess_encoding
set_mime_type
inspect
Then I run a "puts email.message.methods and a "puts email.message.class" for good measure. The example method call is not in the list.
So I go diving into https://github.com/nu7hatch/gmail/blob/master/lib/gmail/message.rb.
No methods are defined there either, but I notice that mime/message is defined, so I go over there to look at its methods: http://rubydoc.info/gems/mime/0.1/MIME/Message
There is no save_attachments_to method here either.
Where the deuce is this method? The gmail gem does not define attachment methods, so the whole thing must be inherited from somewhere. Where? And where's the call that inherits it?

Answer 1

The reason you can't find it is because it doesn't exist. I'm not sure why. I downloaded the gem and played with it for a while in irb:
1.9.3-p194 :066 > x.message.attachments
=> [#<Mail::Part:70234804200840, Multipart: false, Headers: <Content-Type: application/vnd.ms-excel; name="MVBINGO.xls">, <Content-Transfer-Encoding: base64>, <Content-Disposition: attachment; filename="MVBINGO.xls">, <Content-Description: MVBINGO.xls>>]
1.9.3-p194 :063 > x.message.save_attachments_to(folder)
NoMethodError: undefined method `save_attachments_to' for #<Mail::Message:0x007fc1a3875818>
from /Users/Qsario/.rvm/gems/ruby-1.9.3-p194/gems/mail-2.4.4/lib/mail/message.rb:1289:in `method_missing'
from (irb):63
from /Users/Qsario/.rvm/rubies/ruby-1.9.3-p194/bin/irb:16:in `<main>'
Not very helpful. Ordinarily, you can do something like
puts my_obj.method(:some_method_name).source_location
But when the method in question does not exist, that won't help you very much. EDIT: Now that I look, this exact bug is already on their issue tracker. A few people have posted code to implement the non-existent function, such as this code by a-b:
folder = Dir.pwd # for example
email.message.attachments.each do |f|
File.write(File.join(folder, f.filename), f.body.decoded)
end

Answer 2

Thanks for the sanity check Qsario. :-)
Here is code that works in Ruby 1.9.3 (1.9.3-p194):
gmail = Gmail.connect('username#gmail.com', 'pass')
gmail.inbox.emails.each do |email|
email.message.attachments.each do |f|
File.write(File.join(local_path, f.filename), f.body.decoded)
end
end
Here is code that works in 1.9.2 (1.9.2-p320) and 1.9.3 (1.9.3-p194):
gmail = Gmail.connect('username#gmail.com', 'pass')
gmail.inbox.emails.each do |email|
email.message.attachments.each do |file|
File.open(File.join(local_path, "name-of-file.doc or use file.filename"), "w+b", 0644 ) { |f| f.write file.body.decoded }
end
end