Re: MIME vs HTML

[wmperry@aventail.com (William M. Perry)]

Lars Magne Ingebrigtsen <larsi@ifi.uio.no> writes:

> Aha!  Now I know how Microsofties do MIME properly -- they don't.
> Instead they do HTML with
> 
> <img src="cid:003e01be1642$a526f940$b86efea9@win">

  There's nothing wrong with this.  Perfectly reasonable given the age of
the CID URL draft. :)  I actually sent you email about how we could make
this easy for Emacs/W3 to support. :)

> tags inside, which allows an entire document consisting of many parts to
> be rendered.  Which makes sense.
> 
> If Gnus is to render this properly, I guess Gnus will have to transform
> these so that w3 can pick up the images properly...  (Gnus will have to
> stop rendering the HTML in one window and copying it over, though, since
> images don't survive that very well.  William -- any comments?)

  If GNUs can bind a variable or provide a function that would allow a
'cid' URL handler in Emacs/W3 to get the part and header information
associated with a content-id, I could just do:

(url-register-protocol 'cid nil 'url-identity-expander)

(defun gnus-mime-get-part-by-content-id (cid)
  "Returns a MIME part given it's content-id."
  .
  .
  .
  )

(defun gnus-part-content-type (part)
  "Returns the content-type of a MIME part"
  .
  .
  .
  )

(defun gnus-part-content-encoding (part)
  "Returns the content-encoding of a MIME part"
  .
  .
  .
  )

(defun url-cid (url)
  (set-buffer (get-buffer-create url-working-buffer))
  (let ((content-type nil)
	(encoding nil)
	(part nil)
	(data nil))
    (if (not (string-match "^cid:\\(.*\\)" url))
	(message "Malformed CID URL: %s" url)
      (setq url (url-unhex-string (match-string 1 url))
	    part (gnus-mime-get-part-by-content-id url))
      (if (not part)
	  (message "Unknown CID encounterred: %s" url)
	(setq data (gnus-part-body part)
	      content-type (gnus-part-content-type part)
	      encoding (gnus-part-content-encoding part))
	(if (= 0 (length content-type)) (setq content-type "text/plain"))
	(if (= 0 (length encoding)) (setq encoding "8bit"))
	(setq url-current-content-length (length data)
	      url-current-mime-type content-type
	      url-current-mime-encoding encoding
	      url-current-mime-headers (list (cons "content-type" content-type)
					     (cons "content-encoding" encoding)))
	(and data (insert data))))))

And voila!

-Bill P.