TAP::Parser::IteratorFactory - Figures out which SourceHandler objects to use for a given Source

Version 3.23

  use TAP::Parser::IteratorFactory;
  my $factory = TAP::Parser::IteratorFactory->new({ %config });
  my $iterator  = $factory->make_iterator( $filename );

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_handlers, how detect_source works.

Creates a new factory class:

  my $sf = TAP::Parser::IteratorFactory->new( $config );

$config is optional. If given, sets config and calls load_handlers.

Registers a new TAP::Parser::SourceHandler with this factory.

  __PACKAGE__->register_handler( $handler_class );

List of handlers that have been registered.

 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 } });

 $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

croaks on error.

  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.

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.

Please see SUBCLASSING in TAP::Parser for a subclassing overview.

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 vars '@ISA';

  use TAP::Parser::IteratorFactory;

  @ISA = qw( 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;

Steve Purkis

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.

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