TAP::Parser::IteratorFactory(3p) | Perl Programmers Reference Guide | TAP::Parser::IteratorFactory(3p)

# NAME

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

# VERSION

Version 3.48

# 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

2025-01-28 | perl v5.40.1