Re: Question candide sur HTML

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Auteur: Daniel Veillard
Date:  
À: Laurent Julliard
CC: guilde
Sujet: Re: Question candide sur HTML
>
>
> Y-a-t il un moyen de dire dans le langage HTML qu'un document ne doit
> pas etre pris en compte dans le cache d'un browser. Le but etant de
> forcer le rechargement a chaque nouvel acces.


Au niveau HTML non, je crois pas.
C'est au niveau HTTP (transport) que ca se passe. Il faut demander a apache
de rajouter un header donnant la limite de validite du document.
J'ai pas la doc sous les yeux mais le mieux c'est de regarder
s'il y a des options de ce type dans les docs de configuration
de Apache.

D'apres un bref coup d'oeil aux sources, c'est le module mod_expires
de apache qui fournit ca . D'apres le source :

--------------------------------------------------------------
 * DIRECTIVE SYNTAX
 *
 * Valid directives are:
 *
 *     ExpiresActive on | off
 *     ExpiresDefault <code><seconds>
 *     ExpiresByType type/encoding <code><seconds>
 *
 * Valid values for <code> are:
 *
 *     'M'      expires header shows file modification date + <seconds>
 *     'A'      expires header shows access time + <seconds>
 *
 *              [I'm not sure which of these is best under different
 *              circumstances, I guess it's for other people to explore.
 *              The effects may be indistinguishable for a number of cases]
 *
 * <seconds> should be an integer value [acceptable to atoi()]
 *
 * There is NO space between the <code> and <seconds>.
 *
 * For example, a directory which contains information which changes
 * frequently might contain:
 *
 *     # reports generated by cron every hour.  don't let caches
 *     # hold onto stale information
 *     ExpiresDefault M3600
 *
 * Another example, our html pages can change all the time, the gifs
 * tend not to change often:
 * 
 *     # pages are hot (1 week), images are cold (1 month)
 *     ExpiresByType text/html A604800
 *     ExpiresByType image/gif A2592000
 *
 * Expires can be turned on for all URLs on the server by placing the
 * following directive in a conf file:
 *
 *     ExpiresActive on
 *
 * ExpiresActive can also appear in .htaccess files, enabling the
 * behaviour to be turned on or off for each chosen directory.
 *
 *     # turn off Expires behaviour in this directory
 *     # and subdirectories
 *     ExpiresActive off
 *
 * Directives defined for a directory are valid in subdirectories
 * unless explicitly overridden by new directives in the subdirectory
 * .htaccess files.
 *
 * ALTERNATIVE DIRECTIVE SYNTAX
 *
 * Directives can also be defined in a more readable syntax of the form:
 *
 *     ExpiresDefault "<base> [plus] {<num> <type>}*"
 *     ExpiresByType type/encoding "<base> [plus] {<num> <type>}*"
 *
 * where <base> is one of:
 *      access  
 *      now             equivalent to 'access'
 *      modification
 *
 * where the 'plus' keyword is optional
 *
 * where <num> should be an integer value [acceptable to atoi()]
 *
 * where <type> is one of:
 *      years
 *      months
 *      weeks
 *      days
 *      hours
 *      minutes
 *      seconds
 *
 * For example, any of the following directives can be used to make
 * documents expire 1 month after being accessed, by default:
 *
 *      ExpiresDefault "access plus 1 month"
 *      ExpiresDefault "access plus 4 weeks"
 *      ExpiresDefault "access plus 30 days"
 *
 * The expiry time can be fine-tuned by adding several '<num> <type>'
 * clauses:
 *
 *      ExpiresByType text/html "access plus 1 month 15 days 2 hours"
 *      ExpiresByType image/gif "modification plus 5 hours 3 minutes"
 *
----------------------------------------------------------


Ca doit te permettre de faire ce que tu veux ...

Daniel

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