Implementing an upload controller like Basecamp

Question

Wondering how I could implement an upload controller like the Basecamp API, where you can upload a file attachment, receive an XML response containing an ID for that photo, then use that to reference the file in a subsequent XML post to attach the XML record to the file attachment...

Answer 1

Basically all you need is a plugin that manages the uploaded file, like Paperclip or Attachment_fu. These plugins allow to interact with the files as you would a database record, so there will be an id attached to each file.

Then make sure that you have a xml declaration in the respond_to block in your controller.

respond_to do |format|
  format.html
  format.xml { #return the id for the file }
end

Answer 2

Surprising that there is apparently no documentation for doing this anywhere to be found. I ended up stumbling across a document on the Basecamp website describing how their file attachment process works for API users and used it as a guideline.

http://developer.37signals.com/basecamp/

with help from this article about posting files:

http://www.codevil.com/index.php/2009/05/23/posting-and-getting-files-in-rubyrails/

I modified my initial setup so that, rather than passing the tag in the XML, they first post a file and receive an file ID in response.

Then they post the XML with that reference and their .

Then I use before_validation and after_save callbacks to set the file with Paperclip, and remove the tmp file after the save.