POE::Component::WWW::Cache::Google - non-blocking wrapper around WWW::Cache::Google
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.
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.
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.
0
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.
WWW::Cache::Google
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.
$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:
uri
event
{ event => 'results_event', }
Mandatory. Specifies the name of the event to emit when results are ready. See OUTPUT section for more information.
{ 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)
-e
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 existence 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 => 'random', _another => 'more', }
Optional. Any keys starting with _ (underscore) will not affect the component and will be passed back in the result intact.
_
$poe_kernel->post( google_cache => 'shutdown' );
Takes no arguments. Tells the component to shut itself down.
$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 receive input in the $_[ARG0] in a form of a hashref. The possible keys/value of that hashref are as follows:
cache()
$_[ARG0]
'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.
'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.
{ '_blah' => 'foos' }
Any arguments beginning with _ (underscore) passed into the cache() event/method will be present intact in the result.
POE, WWW::Cache::Google
Fork this module on GitHub: https://github.com/zoffixznet/POE-Component-Bundle-WebDevelopment
To report bugs or request features, please use https://github.com/zoffixznet/POE-Component-Bundle-WebDevelopment/issues
If you can't access GitHub, you can email your request to bug-POE-Component-Bundle-WebDevelopment at rt.cpan.org
bug-POE-Component-Bundle-WebDevelopment at rt.cpan.org
Zoffix Znet <zoffix at cpan.org> (http://zoffix.com/, http://haslayout.net/)
You can use and distribute this module under the same terms as Perl itself. See the LICENSE file included in this distribution for complete details.
LICENSE
To install POE::Component::Bundle::WebDevelopment, copy and paste the appropriate command in to your terminal.
cpanm
cpanm POE::Component::Bundle::WebDevelopment
CPAN shell
perl -MCPAN -e shell install POE::Component::Bundle::WebDevelopment
For more information on module installation, please visit the detailed CPAN module installation guide.