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' => ' 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' => ' '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, "" (,
)
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
. 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:
* RT: CPAN's request tracker
* AnnoCPAN: Annotated CPAN documentation
* CPAN Ratings
* Search CPAN
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.