README

SYNOPSIS

        use WWW::Mechanize::Cached;
    
        my $cacher = WWW::Mechanize::Cached->new;
        $cacher->get( $url );
    
        # or, with your own Cache object
        use CHI;
        use WWW::Mechanize::Cached;
    
        my $cache = CHI->new(
            driver   => 'File',
            root_dir => '/tmp/mech-example'
        );
    
        my $mech = WWW::Mechanize::Cached->new( cache => $cache );
        $mech->get("http://www.wikipedia.org");

DESCRIPTION

    Uses the Cache::Cache hierarchy by default to implement a caching Mech.
    This lets one perform repeated requests without hammering a server
    impolitely. Please note that Cache::Cache has been superceded by CHI,
    but the default has not been changed here for reasons of backwards
    compatibility. For this reason, you are encouraged to provide your own
    CHI caching object to override the default.

CONSTRUCTOR

 new

    Behaves like, and calls, WWW::Mechanize's new method. Any params, other
    than those explicitly listed here are passed directly to
    WWW::Mechanize's constructor.

    You may pass in a cache => $cache_object if you wish. The $cache_object
    must have get() and set() methods like the Cache::Cache family.

    The default Cache object is set up with the following params:

        my $cache_params = {
            default_expires_in => "1d", namespace => 'www-mechanize-cached',
        };
    
        $cache = Cache::FileCache->new( $cache_params );

    This should be fine if you only want to use a disk-based cache, you
    only want to cache results for 1 day and you're not in a shared hosting
    environment. If any of this presents a problem for you, you should pass
    in your own Cache object. These defaults will remain unchanged in order
    to maintain backwards compatibility.

    For example, you may want to try something like this:

        use WWW::Mechanize::Cached;
        use CHI;
    
        my $cache = CHI->new(
            driver   => 'File',
            root_dir => '/tmp/mech-example'
        );
    
        my $mech = WWW::Mechanize::Cached->new( cache => $cache );
        $mech->get("http://www.wikipedia.org");

METHODS

    Most methods are provided by WWW::Mechanize. See that module's
    documentation for details.

 cache( $cache_object )

    Requires an caching object which has a get() and a set() method. Using
    the CHI module to create your cache is the recommended way. See new()
    for examples.

 is_cached()

    Returns true if the current page is from the cache, or false if not. If
    it returns undef, then you don't have any current request.

 positive_cache( 0|1 )

    As of v1.36 positive caching is enabled by default. Up to this point,
    this module had employed a negative cache, which means it cached 404
    responses, temporary redirects etc. In most cases, this is not what you
    want, so the default behaviour now better reflects this. You can revert
    to the negative cache quite easily:

        # cache everything (404s, all 300s etc)
        $mech->positive_cache( 0 );

 ref_in_cache_key( 0|1 )

    Allow the referring URL to be used when creating the cache key. This is
    off by default. In almost all cases, you will not want to enable this,
    but it is available to you for reasons of backwards compatibility and
    giving you enough rope to hang yourself.

    Previous to v1.36 the following was in the "BUGS AND LIMITATIONS"
    section:

        It may sometimes seem as if it's not caching something. And this may well
        be true. It uses the HTTP request, in string form, as the key to the cache
        entries, so any minor changes will result in a different key. This is most
        noticable when following links as L<WWW::Mechanize> adds a C<Referer>
        header.

    See RT #56757 for a detailed example of the bugs this functionality can
    trigger.

 cache_undef_content_length( 0 | 'warn' | 1 )

    This is configuration option which adjusts how caching behaviour
    performs when the Content-Length header is not specified by the server.

    Default behaviour is 0, which is not to cache.

    Setting this value to 1, will cache pages even if the Content-Length
    header is missing, which was the default behaviour prior to the
    addition of this feature.

    And thirdly, you can set the value to the string 'warn', to warn if
    this scenario occurs, and then not cache it.

 cache_zero_content_length( 0 | 'warn' | 1 )

    This is configuration option which adjusts how caching behaviour
    performs when the Content-Length header is equal to 0.

    Default behaviour is 0, which is not to cache.

    Setting this value to 1, will cache pages even if the Content-Length
    header is 0, which was the default behaviour prior to the addition of
    this feature.

    And thirdly, you can set the value to the string 'warn', to warn if
    this scenario occurs, and then not cache it.

 cache_mismatch_content_length( 0 | 'warn' | 1 )

    This is configuration option which adjusts how caching behaviour
    performs when the Content-Length header differs from the length of the
    content itself. ( Which usually indicates a transmission error )

    Setting this value to 0, will silenly not cache pages with a
    Content-Length mismatch.

    Setting this value to 1, will cache pages even if the Content-Length
    header conflicts with the content length, which was the default
    behaviour prior to the addition of this feature.

    And thirdly, you can set the value to the string 'warn', to warn if
    this scenario occurs, and then not cache it. ( This is the default
    behaviour )

UPGRADING FROM 1.40 OR EARLIER

    Caching behaviour has changed since 1.40, and this may result in pages
    that were previously cached start failing to cache, and in some cases,
    emit warnings.

    To return to the 1.40 behaviour:

        $mech->cache_undef_content_length(1);  # Default is 0
        $mech->cache_zero_content_length(1);   # Default is 0
        $mech->cache_mismatch_content_length(1); # Default is 'warn'

THANKS

    Iain Truskett for writing this in the first place. Andy Lester for
    graciously handing over maintainership. Kent Fredric for adding content
    length handling.

SUPPORT

    You can find documentation for this module with the perldoc command.

        perldoc WWW::Mechanize::Cached

      * Search CPAN

      https://metacpan.org/module/WWW::Mechanize::Cached

SEE ALSO

    WWW::Mechanize, WWW::Mechanize::Cached::GZip.