Re: Allow people to circumvent W3 for HTML

[Simon Josefsson <jas@extundo.com>]

Daniel Pittman <daniel@rimspace.net> writes:

>> Doesn't
>> 
>> text/html: html2text %s; copiousoutput
>> 
>> or something in ~/.mailcap work?
> 
> Er, didn't last time I tried... ...time passes...
> 
> ...or maybe not. I thought I did have it in there. Let me try again.
> 
> No. Adding it and restarting XEmacs (and, thus, Gnus) completely failed
> to cause to it take effect: the HTML mail still caused W3 to load.
> 
> Lesse... Within `mailcap-mime-data', we have my values *first* in the
> list, with the W3 values last.
> 
> W3 is definitely chosen; there isn't an issue with searching this data
> in reverse order, is there? More testing...
> 
> Found it. The breakage comes for `mm-display-inline'
> 
> Basically, `mm-display-part' comes in, makes sure the mailcap files are
> parsed, locates the viewer from the mailcap data (getting html2text),
> then asks:
> 
>   (if (and (mm-inlinable-p handle)
>            (mm-inlined-p handle))
> 
> When this passes, it calls `mm-display-inline' which unconditionally
> uses W3. The HTML part isn't considered to be capable of being inlined
> unless W3 is present.
> 
> 
> Now, having looked at this, I can most certainly go and fix this problem
> by redefining the stuff in the inlined type data structures to call my
> shell command and parse the content that way.
> 
> However, in answer to your original question: No, adding that to
> .mailcap or *any* other mailcap file will never work when the W3 library
> is installed.
> 
> So, bug or feature? You decide ... but I would suggest adding a fairly
> easy to reach default that let the end user call a shell command to
> reformat the text and make it inline rather than forcing W3.

I'd say bug, if you say something in .mailcap, Gnus should use that
unless you've told it otherwise somewhere else or if there is a good
reason to do something else.

> I will post my solution once it's written; it should be capable of doing
> that if someone with commit access wants to add it.

IMHO even if nothing is specified in .mailcap, Gnus should use a
customizable variable to say whether w3, w3m or some other Emacs web
browsers should be used instead of hardcoding it to w3.  So you should
be able to override the text/html viewer used either by .mailcap or by
changing the variable (the latter having more priority).