Re: Adding MIME viewers

[Lars Magne Ingebrigtsen <larsi@gnus.org>]

Toby Speight <Toby.Speight@streapadair.freeserve.co.uk> writes:

> Has anyone written a good guide for writing viewers for MIME-types
> not built-in to Gnus?  In particular, I've recently installed Stefan
> Monnier's diff-mode.el, and I'd like to use his font-lock rules to
> fontify "text/x-patch" bodyparts.

I've now added the following section to the Emacs-MIME manual:

New Viewers
===========

   Here's an example viewer for displaying `text/enriched' inline:

     (defun mm-display-enriched-inline (handle)
       (with-temp-buffer
         (mm-insert-part handle)
         (save-window-excursion
           (enriched-decode (point-min) (point-max))
           (setq text (buffer-string))))
       (mm-insert-inline handle text))

   We see that the function takes a MIME handle as its parameter.  It
then goes to a temporary buffer, inserts the text of the part, does some
work on the text, stores the result, goes back to the buffer it was
called from and inserts the result.

   The two important helper functions here are `mm-insert-part' and
`mm-insert-inline'.  The first function inserts the text of the handle
in the current buffer.  It handles charset and/or content transfer
decoding.  The second function just inserts whatever text you tell it
to insert, but it also sets things up so that the text can be
"undisplayed' in a convenient manner.


-- 
(domestic pets only, the antidote for overdose, milk.)
  larsi@gnus.org * Lars Magne Ingebrigtsen