title: iPhone image (binary) file post to a Rails app
body: <p>I am a backend Rails developer of an API.  The API must accept an image upload from an iPhone client.   </p>
  
  <p>My question is what the Content-Type for the entire POST must be to allow the upload and not get trapped by the InvalidAuthenticityToken issue.  It will have to be a multipart type because there are (in one case) 3 image files, and the normal textual POST parameters.  We have control of the iPhone code, and would rather not make it e.g., a two stage where a token is requested from the server and then is submitted with the POST. </p>
  
  <p>Thanks,<br/>
  Craig Cook </p>