poet::import(3pm) [debian man page]

Poet::Import(3pm)					User Contributed Perl Documentation					 Poet::Import(3pm)

NAME

       Poet::Import -- Import Poet quick vars and utilities

SYNOPSIS

	   # In a script...
	   use Poet::Script qw($conf $poet $log :file);

	   # In a module...
	   use Poet qw($conf $poet $log :file);

DESCRIPTION

       Poet makes it easy to import certain variables (known as "quick vars") and utility sets into any script or module in your environment.

       In a script:

	   use Poet::Script qw(...);

       and in a module:

	   use Poet qw(...);

       where "..." contains one or more quick var names (e.g. $conf, $poet) and/or utility tags (e.g. ":file", ":web").

       (Note that "use Poet::Script" is also necessary for initializing the environment, even if you don't care to import anything, whereas "use
       Poet" has no effect other than importing.)

QUICK VARS

       Here is the built-in list of quick vars you can import. Some of the variables are singletons, and some of them are specific to each package
       they are imported into.

       $poet
	   The global environment object, provided by Poet::Environment. This provides information such as the root directory and paths to
	   subdirectories.

	   For backward compatibility this is also available as $env.

       $conf
	   The global configuration object, provided by Poet::Conf.

       $cache
	   The cache for the current package, provided by Poet::Cache.

       $log
	   The logger for the current package, provided by Poet::Log.

UTILITIES

   Default utilities
       The utilities in Poet::Util::Debug are always imported, with no tag necessary.

   :file
       This tag imports all the utilities in Poet::Util::File.

   :web
       This tag imports all the utilities in Poet::Util::Web. It is automatically included in all Mason components.

MASON COMPONENTS

       Every Mason component automatically gets this on top:

	   use Poet qw($conf $poet :web);

       "$m->cache" and "$m->log" will get you the cache and log objects for a particular Mason component.

CUSTOMIZING

   Adding variables
       To add your own variable, define a method called provide_var_varname in "MyApp::Import". For example to add a variable $dbh:

	   package MyApp::Import;
	   use Poet::Moose;
	   extends 'Poet::Import';

	   method provide_var_dbh ($caller) {
	       # Generate and return a dbh.
	       # $caller is the package importing the variable.
	       # $poet is the current Poet environment.
	   }

       "provide_dbh" can return a single global value, or a dynamic value depending on $caller.

       Now your scripts and libraries can do

	   use Poet::Script qw($dbh);
	   use Poet qw($dbh);

   Adding utility tags
       To add your own utility tag, define a class "MyApp::Util::Mytagname" that exports a set of functions via the ':all' tag. For example:

	   package MyApp::Util::Hash;
	   use Hash::Util qw(hash_seed all_keys);
	   use Hash::MoreUtils qw(slice slice_def slice_exists);

	   our @EXPORT_OK = qw(hash_seed all_keys slice slice_def slice_exists);
	   our %EXPORT_TAGS = ( 'all' => @EXPORT_OK );

	   1;

       Now your scripts and libraries can do

	   use Poet::Script qw(:hash);
	   use Poet qw(:hash);

SEE ALSO

       Poet

AUTHOR

       Jonathan Swartz <swartz@pobox.com>

COPYRIGHT AND LICENSE

       This software is copyright (c) 2012 by Jonathan Swartz.

       This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

perl v5.14.2							    2012-06-05							 Poet::Import(3pm)

Poet::Cache(3pm)					User Contributed Perl Documentation					  Poet::Cache(3pm)

NAME

       Poet::Cache -- Poet caching with CHI

SYNOPSIS

	   # In a conf file...
	   cache:
	      defaults:
		 driver: Memcached
		 servers: ["10.0.0.15:11211", "10.0.0.15:11212"]

	   # In a script...
	   use Poet::Script qw($cache);

	   # In a module...
	   use Poet qw($cache);

	   # In a component...
	   my $cache = $m->cache;

	   # For an arbitrary namespace...
	   my $cache = Poet::Cache->new(namespace => 'Some::Namespace')

	   # then...
	   my $customer = $cache->get($name);
	   if ( !defined $customer ) {
	       $customer = get_customer_from_db($name);
	       $cache->set( $name, $customer, "10 minutes" );
	   }
	   my $customer2 = $cache->compute($name2, "10 minutes", sub {
	       get_customer_from_db($name2)
	   });

DESCRIPTION

       Poet::Cache is a subclass of CHI. CHI provides a unified caching API over a variety of storage backends, such as memory, plain files,
       memory mapped files, memcached, and DBI.

       Each package and Mason component uses its own CHI namespace so that caches remain separate.

CONFIGURATION

       The Poet configuration entry 'cache', if any, will be passed to Poet::Cache->config(). This can go in any Poet conf file, e.g. "local.cfg"
       or "global/cache.cfg".

       Here's a simple configuration that caches everything to files under "data/cache". This is also the default if no configuration is present.

	  cache:
	     defaults:
		driver: File
		root_dir: ${root}/data/cache

       Here's a more involved configuration that defines several "storage types" and assigns each namespace a storage type.

	  cache:
	     defaults:
		expires_variance: 0.2
	     storage:
		file:
		   driver: File
		   root_dir: ${root}/data/cache
		memcached:
		   driver: Memcached
		   servers: ["10.0.0.15:11211", "10.0.0.15:11212"]
		   compress_threshold: 4096
	     namespace:
		/some/component:       { storage: file, expires_in: 5min }
		/some/other/component: { storage: memcached, expires_in: 1h }
		Some::Library:	       { storage: memcached, expires_in: 10min }

       Given the configuration above, and the code

	   package Some::Library;
	   use Poet qw($cache);

       this $cache will be created with properties

	   driver: Memcached
	   servers: ["10.0.0.15:11211", "10.0.0.15:11212"]
	   compress_threshold: 4096
	   expires_in: 10min

USAGE

   Obtaining cache handle
       o   In a script (namespace will be 'main'):

	       use Poet::Script qw($cache);

       o   In a module "MyApp::Foo" (namespace will be 'MyApp::Foo'):

	       use Poet qw($cache);

       o   In a component "/foo/bar" (namespace will be '/foo/bar'):

	       my $cache = $m->cache;

       o   Manually for an arbitrary namespace:

	       my $cache = Poet::Cache->new(namespace => 'Some::Namespace');

	       # or

	       my $cache = MyApp::Cache->new(category => 'Some::Namespace');

   Using cache handle
	   my $customer = $cache->get($name);
	   if ( !defined $customer ) {
	       $customer = get_customer_from_db($name);
	       $cache->set( $name, $customer, "10 minutes" );
	   }
	   my $customer2 = $cache->compute($name2, "10 minutes", sub {
	       get_customer_from_db($name2)
	   });

       See CHI and Mason::Plugin::Cache for more details.

MODIFIABLE METHODS

       These methods are not intended to be called externally, but may be useful to override or modify with method modifiers in subclasses.

       initialize_caching
	   Called once when the Poet environment is initialized. By default, calls "__PACKAGE__->config" with the configuration entry 'cache'.

SEE ALSO

       Poet

AUTHOR

       Jonathan Swartz <swartz@pobox.com>

COPYRIGHT AND LICENSE

       This software is copyright (c) 2012 by Jonathan Swartz.

       This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

perl v5.14.2							    2012-06-05							  Poet::Cache(3pm)