NAME
POE::Component::Basement
SYNOPSIS
package POE::MyComponent;
# use as base
use base qw/ POE::Component::Basement /;
# where the initializations happen (see Class::Std)
sub BUILD { ... }
# see also Class::Std and Class::Data::Inheritable also
# for accessor creation etc.
# define states
sub state_one : State( :inline<_start> ) { ... }
sub state_two : State( :object<foo> ) { ... }
sub state_three : State( :package<bar> ) { ... }
# combined
sub state_multi : State( :inline<foobar> :package<snafoo> ) { ... }
...
# chained events
sub first : State( :object<foo> :chained<bar> ) { ... }
sub second : State( :object<bar> ) { ... }
...
# calling in a row
sub first : State( :object<foo> :next<bar> ) { ... }
sub second : State( :object<bar> ) { ... }
...
# usage
my $comp = POE::MyComponent->new ({
# single alias or array reference for multiple
aliases => [qw/ mycomp shub_niggurath /],
... # your specific init_arg's.
});
DESCRIPTION
Provides Class::Std and base POE component functionality. This module is
still kinda experimental.
CLASS AND INSTANCE DATA
Setting "session_class"
Determines on which class the session should be built on. To use, for
instance, POE::Session::MessageBased, set the option like this:
MyComponent->session_class( 'POE::Session::MessageBased' );
The default is POE::Session.
Option "aliases"
Can be a single value to be set as alias, or an array reference. If the
latter, POE::Kernel's "alias_set" is called for each of it's elements.
This must be supplied as argument to the "new" method. See SYNOPSIS for
examples.
ATTRIBUTES
This module just uses the attribute "State" and delegates all other
attribute handling to Class::Std. Parameters can multiple, separated by
spaces. They look like those of Class::Std to be coherent. As an
example:
sub start_event : State( :inline<_start> ) {
...
}
This would create an "inline_state" for our session, named "_start".
inline, package and object
Create "inline_states", "package_states" or "object_states" in your
session. Multiple specifications of these parameters cause multiple
events to be defined. Have a look at POE for more information.
chained
sub first : State( :inline<_start> :chained<end> ) {
print "Called first.\n";
return 23;
}
sub end : State( :inline<end> ) {
my $last_return = $_[ARG0];
print "Called second. First returned $last_return\n";
}
Specifies with which event the current state should be chained. If you
use "chained", the given event will be triggered after the sub has
completed. It's return values will be passed to the chained event.
next
# the event gets triggered
POE::Kernel->yield( foo => 333 );
sub first : State( :inline<foo> :next<bar> ) {
my ( $nr ) = $_[ARG0];
...
}
sub second : State( :inline<bar> ) {
my ( $nr ) = $_[ARG0];
...
}
An event that was specified with "next" is triggered right after
completion of the current subroutine. The "next" event gets the same
parameters as the current.
error
sub first : State( :inline<foo> :error<error_occured> ) {
die "in the name of Cthulhu";
}
sub second : State( :inline<error_occured> ) {
my $error = $_[ARG0];
print 'An Error has occured: ' . $error;
}
If an "error" handling state is defined, "PCB" will build an "eval"
block around the subroutine call and emit the event specified with
"error". First argument is the error message.
INHERITANCE
Currently, you can overload the called methods in package and object
states. Though you have to do this without specifying a new "State()"
attribute. The new method has the same attributes as the overriden. The
latter can also be called with NEXT. This basic way works like:
# the original
package Original;
sub whatever : State( :package<_start> ) { ... }
...
# the new one
package NewOne;
use base qw/ Original /;
sub whatever { ... }
But for information, I'm planning the possibility to override specific
events.
METHODS
Methods starting with an underline ("_") is thought as internal to
POE::Component::Basement and should therefore not be called directly.
_parse_attributes
( $name, $param ) = _parse_attribute( $attribute )
Takes an attribute and tries to split it into name and parameters.
Returns undef if nothing usable found.
new
Constructor. See SYNOPSIS for usage. This overrides the "new" method
provided by Class::Std.
MODIFY_CODE_ATTRIBUTES
This is an internal sub that's responsible for building your state-map,
as it is called on specification of an attribute. See perldoc's
attributes for more information about this subject. This is an *internal
function*, do not call directly.
_create_modified_state
$code = _create_modified_state( \&coderef, \%params );
Does the wrapping for the more enhanced attributes. Internal, do not
call.
register_states
void register_states( $class, $coderef, { state_name => 'type' } );
Registers states corresponding to a specific code reference. Accepted
state names are "inline", "package" and "object". Internal, do not call.
_flatten_inheritance
@classes_in_family = _flatten_inheritance( $rootclass )
Returns an array with names of classes used in the specified $rootclass'
inheritance tree. This is internal, do not call.
get_states
\%struct = $comp->get_states()
Returns a structure containing the defined inline, package and object
states ready to use for POE::Sessions constructor. Internal and
restricted, do not call.
_get_symbol_name
$subname = _get_symbol_name( $class, $coderef );
Searches for a code reference in the symbol table of a class and returns
the sub's name if found. Otherwise undef. Do not call.
_parse_parameters
%parameters = _parse_parameters( $parameter_string )
This function looks for parameters formed like :name<value> and returns
them in ( name => value, .. ) like pairs. Dies on malformed or unknown
parameters. Internal method, do not call.
SEE ALSO
POE, Class::Std, Class::Data::Inheritable
REQUIRES
POE, Class::Std, Carp, Scalar::Util, NEXT, Sub::Installer,
Class::Data::Inheritable
AUTHOR
Robert Sedlacek <phaylon@dunkelheit.at>
LICENSE
You can copy and/or modify this module under the same terms as perl
itself.