/ 
POE-Component-WWW-Cache-Google-0.0201
/ POE::Component::WWW::Cache::Google

NAME

POE::Component::WWW::Cache::Google - non-blocking wrapper around WWW::Cache::Google

SYNOPSIS

use strict;
use warnings;

use POE qw(Component::WWW::Cache::Google);

my $poco = POE::Component::WWW::Cache::Google->spawn;

POE::Session->create(
    package_states => [ main => [qw(_start cache)] ],
);

$poe_kernel->run;

sub _start {
    $poco->cache( {
            uri   => 'http://zoffix.com/',
            event => 'cache',
            fetch => 1,
        }
    );
}

sub cache {
    my $in_ref = $_[ARG0];

    print "Cache URI for $in_ref->{uri} is: $in_ref->{cache}\n";
    print "Content:\n$in_ref->{content}\n";

    $poco->shutdown;
}

Using event based interface is also possible of course.

DESCRIPTION

The module is a non-blocking wrapper (for what it's worth) around WWW::Cache::Google which provides interface to get Google's "cache" URIs as well as optionally fetch contents of such URIs.

CONSTRUCTOR

spawn

my $poco = POE::Component::WWW::Cache::Google->spawn;

POE::Component::WWW::Cache::Google->spawn(
    alias => 'google_cache',
    options => {
        debug => 1,
        trace => 1,
        # POE::Session arguments for the component
    },
    debug => 1, # output some debug info
);

The spawn method returns a POE::Component::WWW::Cache::Google object. It takes a few arguments, all of which are optional. The possible arguments are as follows:

alias

->spawn( alias => 'google_cache' );

Optional. Specifies a POE Kernel alias for the component.

options

->spawn(
    options => {
        trace => 1,
        default => 1,
    },
);

Optional. A hashref of POE Session options to pass to the component's session.

debug

->spawn(
    debug => 1
);

When set to a true value turns on output of debug messages. Defaults to: 0.

METHODS

cache

$poco->cache( {
        event       => 'event_for_output',
        uri         => 'http://zoffix.com',
        max_size    => 1000,
        fetch       => 1, # or fetch => \'file_name', 
        overwrite => 1,
        _blah       => 'pooh!',
        session     => 'other',
    }
);

Takes a hashref as an argument, does not return a sensible return value. See WWW::Cache::Google event's description for more information.

session_id

my $poco_id = $poco->session_id;

Takes no arguments. Returns component's session ID.

shutdown

$poco->shutdown;

Takes no arguments. Shuts down the component.

ACCEPTED EVENTS

cache

$poe_kernel->post( google_cache => cache => {
        event       => 'event_for_output',
        uri         => 'http://zoffix.com',
        max_size    => 1000,
        fetch       => 1, # or fetch => \'file_name',
        overwrite   => 1,
        _blah       => 'pooh!',
        session     => 'other',
    }
);

Instructs the component to construct a URI to Google's 'cached' URI for the URI given via uri argument. Optionally can fetch page's content or automatically store it in a file. Takes a hashref as an argument, the possible keys/value of that hashref are as follows:

event

{ event => 'results_event', }

Mandatory. Specifies the name of the event to emit when results are ready. See OUTPUT section for more information.

uri

{ uri => 'http://haslayout.net/' }

Mandatory. Specifies the URi which to look up in Google's cache.

fetch

{ fetch => 1 },

{ fetch => \'file_name' }

Optional. Takes either true, false or scalarref values. When set to a false value, the component will not fetch the page. When set to a true value, the component will try to fetch the uri (in Google's cache that is) using LWP::Simple. When set to a scalarref, it will be dereferenced to obtain a filename into which to save the contents. The component will error out if the file already exists (the check is performed via -e) unless overwrite argument (see below) is set to a true value. Defaults to: 0 (no fetching)

overwrite

{ overwrite => 1 }

Optional. Regarded only when the fetch argument (see above) is set to a scalarref which is a filename. Can take either true or false values. When set to a true value will overwrite the filename set via fetch argument if the file already exists. Defaults to: 0 (no overwriting - error out instead)

max_size

{ max_size => 1000, }

Optional. Regarded only when the fetch argument is not a false value. The value you specify (which indicates the maximum length of the content to retrieve) will by passed to LWP::UserAgent's max_size method. Use this argument if you just want to have error checking with regards to actual existance of that cache page. Note: component *does* actually need some content to determine if the cached page exists, thus do not set max_size below 100. By default is not set, thus no limit on the content length is imposed.

session

{ session => 'other' }

{ session => $other_session_reference }

{ session => $other_session_ID }

Optional. Takes either an alias, reference or an ID of an alternative session to send output to.

user defined

{
    _user    => 'random',
    _another => 'more',
}

Optional. Any keys starting with _ (underscore) will not affect the component and will be passed back in the result intact.

shutdown

$poe_kernel->post( google_cache => 'shutdown' );

Takes no arguments. Tells the component to shut itself down.

OUTPUT

$VAR1 = {
    'overwrite' => 1,
    'content' => '<meta http-e.... and so on',
    'fetch' => 1,
    'uri' => 'http://zoffix.com',
    'cache' => bless( do{\(my $o = 'http://www.google.com/search?q=cache:zoffix.com')}, 'URI::http' )
};

The event handler set up to handle the event which you've specified in the event argument to cache() method/event will recieve input in the $_[ARG0] in a form of a hashref. The possible keys/value of that hashref are as follows:

cache

'cache' => bless( do{\(my $o = 'http://www.google.com/search?q=cache:zoffix.com')}, 'URI::http' )

The cache key will contain a URI object representing the URI pointing to the Google's cache page. Note: without actually fetching anything there is no way to know if that URI contains anything but Google's "no found".

content

'content' => '<meta http-e.... and so on',

The content key will contain the content of the Google cache page. This key will be set only when the fetch argument to the cache event/method is set to a true value, or when the fetch argument is set to a scalarref and the cached page was not found on google. When later occurs, the error key will also be present.

error

'error' => 'Doesn\'t look like cache exists',

There won't ever be errors if the fetch argument to cache event/method is set to a false value. Otherwise, the error key will contain the explanation of any errors that occur, including any issues with opening the file when fetch argument is set to a scalarref.

arguments passed to cache event/method

'overwrite' => 1,
'fetch' => 1,
'max_size' => 100,
'uri' => 'http://zoffix.com',

The overwrite, fetch, max_size and uri arguments passed to cache event/method will be present in the output intact.

user defined

{ '_blah' => 'foos' }

Any arguments beginning with _ (underscore) passed into the cache() event/method will be present intact in the result.

SEE ALSO

POE, WWW::Cache::Google

AUTHOR

Zoffix Znet, <zoffix at cpan.org> (http://zoffix.com, http://haslayout.net)

BUGS

Please report any bugs or feature requests to bug-poe-component-www-cache-google at rt.cpan.org, or through the web interface at http://rt.cpan.org/NoAuth/ReportBug.html?Queue=POE-Component-WWW-Cache-Google. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

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

perldoc POE::Component::WWW::Cache::Google

You can also look for information at:

COPYRIGHT & LICENSE

Copyright 2008 Zoffix Znet, all rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.