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TAP::Parser::IteratorFactory(3perl) Perl Programmers Reference Guide TAP::Parser::IteratorFactory(3perl)
 

NAME

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

VERSION

Version 3.30

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
2014-12-27 perl v5.20.2