TAP::Parser::IteratorFactory - Figures out which SourceHandler objects to use for a given Source
VERSION
Version 3.44
SYNOPSIS
use TAP::Parser::IteratorFactory;
my $factory = TAP::Parser::IteratorFactory->new({ %config });
my $iterator = $factory->make_iterator( $filename );
DESCRIPTION
This is a factory class that takes a TAP::Parser::Source and runs it through all the registered TAP::Parser::SourceHandlers to see which one should handle the source.
If you're a plugin author, you'll be interested in how to "register_handler"s, how "detect_source" works.
METHODS
Class Methods
new
Creates a new factory class:
my $sf = TAP::Parser::IteratorFactory->new( $config );
$config
is optional. If given, sets "config" and calls "load_handlers".
register_handler
Registers a new TAP::Parser::SourceHandler with this factory.
__PACKAGE__->register_handler( $handler_class );
handlers
List of handlers that have been registered.
Instance Methods
config
my $cfg = $sf->config;
$sf->config({ Perl => { %config } });
Chaining getter/setter for the configuration of the available source handlers. This is a hashref keyed on handler class whose values contain config to be passed onto the handlers during detection & creation. Class names may be fully qualified or abbreviated, eg:
# these are equivalent
$sf->config({ 'TAP::Parser::SourceHandler::Perl' => { %config } });
$sf->config({ 'Perl' => { %config } });
load_handlers
$sf->load_handlers;
Loads the handler classes defined in "config". For example, given a config:
$sf->config({
MySourceHandler => { some => 'config' },
});
load_handlers
will attempt to load the MySourceHandler
class by looking in @INC
for it in this order:
TAP::Parser::SourceHandler::MySourceHandler
MySourceHandler
croak
s on error.
make_iterator
my $iterator = $src_factory->make_iterator( $source );
Given a TAP::Parser::Source, finds the most suitable TAP::Parser::SourceHandler to use to create a TAP::Parser::Iterator (see "detect_source"). Dies on error.
detect_source
Given a TAP::Parser::Source, detects what kind of source it is and returns one TAP::Parser::SourceHandler (the most confident one). Dies on error.
The detection algorithm works something like this:
for (@registered_handlers) {
# ask them how confident they are about handling this source
$confidence{$handler} = $handler->can_handle( $source )
}
# choose the most confident handler
Ties are handled by choosing the first handler.
SUBCLASSING
Please see "SUBCLASSING" in TAP::Parser for a subclassing overview.
Example
If we've done things right, you'll probably want to write a new source, rather than sub-classing this (see TAP::Parser::SourceHandler for that).
But in case you find the need to...
package MyIteratorFactory;
use strict;
use base 'TAP::Parser::IteratorFactory';
# override source detection algorithm
sub detect_source {
my ($self, $raw_source_ref, $meta) = @_;
# do detective work, using $meta and whatever else...
}
1;
AUTHORS
Steve Purkis
ATTRIBUTION
Originally ripped off from Test::Harness.
Moved out of TAP::Parser & converted to a factory class to support extensible TAP source detective work by Steve Purkis.
SEE ALSO
TAP::Object, TAP::Parser, TAP::Parser::SourceHandler, TAP::Parser::SourceHandler::File, TAP::Parser::SourceHandler::Perl, TAP::Parser::SourceHandler::RawTAP, TAP::Parser::SourceHandler::Handle, TAP::Parser::SourceHandler::Executable