Perl 5 version 18.0 documentation



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


Version 3.26


  1. use TAP::Parser::IteratorFactory;
  2. my $factory = TAP::Parser::IteratorFactory->new({ %config });
  3. 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.


Class Methods


Creates a new factory class:

  1. 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.

  1. __PACKAGE__->register_handler( $handler_class );


List of handlers that have been registered.

Instance Methods


  1. my $cfg = $sf->config;
  2. $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:

  1. # these are equivalent
  2. $sf->config({ 'TAP::Parser::SourceHandler::Perl' => { %config } });
  3. $sf->config({ 'Perl' => { %config } });


  1. $sf->load_handlers;

Loads the handler classes defined in config. For example, given a config:

  1. $sf->config({
  2. MySourceHandler => { some => 'config' },
  3. });

load_handlers will attempt to load the MySourceHandler class by looking in @INC for it in this order:

  1. TAP::Parser::SourceHandler::MySourceHandler
  2. MySourceHandler

croak s on error.


  1. 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:

  1. for (@registered_handlers) {
  2. # ask them how confident they are about handling this source
  3. $confidence{$handler} = $handler->can_handle( $source )
  4. }
  5. # 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...

  1. package MyIteratorFactory;
  2. use strict;
  3. use vars '@ISA';
  4. use TAP::Parser::IteratorFactory;
  5. @ISA = qw( TAP::Parser::IteratorFactory );
  6. # override source detection algorithm
  7. sub detect_source {
  8. my ($self, $raw_source_ref, $meta) = @_;
  9. # do detective work, using $meta and whatever else...
  10. }
  11. 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