6.2. Content Negotiation
There may be different ways to
handle the data that Apache returns, and there are two equivalent
ways of implementing this functionality. The multiviews
method is simpler (and more limited) than the
*.var method, so we shall start with it. The
Config file (from ... /site.multiview) looks
like this:
User webuser
Group webgroup
ServerName www.butterthlies.com
DocumentRoot /usr/www/site.multiview/htdocs
ScriptAlias /cgi-bin /usr/www/cgi-bin
AddLanguage it .it
AddLanguage en .en
AddLanguage ko .ko
LanguagePriority it en ko
<Directory /usr/www/site.multiview/htdocs>
Options +MultiViews
</Directory>
For historical reasons, you have to say:
Options +MultiViews
even though you might reasonably think that
Options All would cover the
case. The general idea is that whenever you want to offer variants on
a file (e.g., JPG, GIF, or bitmap for images, or different languages
for text), multiviews will handle it.
6.2.1. Image Negotiation
Image negotiation is a special
corner of general content negotiation because the Web has a problem
with image files: for instance, some browsers can cope with PNG files
and some can't, and the latter have to be sent the simpler,
more old-fashioned, and bulkier GIF files. The client's browser
sends a message to the server telling it which image files it
accepts:
HTTP_ACCEPT=image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, */*
The server then looks for an appropriate file and returns it. We can
demonstrate the effect by editing our ...
/htdocs/catalog_summer.html file to remove the
.jpg extensions on the image files. The
appropriate lines now look like this:
...
<img src="bench" alt="Picture of a Bench">
...
<img src="hen" alt="Picture of a hencoop like a pagoda">
...
When Apache has the multiViews option turned on
and is asked for an image called bench, it looks
for the smaller of bench.jpg and
bench.gif -- assuming the client's
browser accepts both, of course -- and returns
it.
 |  |  | | 6. MIME, Content and Language Negotiation |  | 6.3. Language Negotiation |
Copyright © 2001 O'Reilly & Associates. All rights reserved.
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