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

# NAME

TAP::Parser::SourceHandler - Base class for different TAP source handlers

# VERSION

Version 3.48

# SYNOPSIS

      # abstract class - don't use directly!
      # see TAP::Parser::IteratorFactory for general usage
      # must be sub-classed for use
      package MySourceHandler;
      use base 'TAP::Parser::SourceHandler';
      sub can_handle    { return $confidence_level }
      sub make_iterator { return $iterator }
      # see example below for more details

# DESCRIPTION

This is an abstract base class for TAP::Parser::Source handlers / handlers.

A "TAP::Parser::SourceHandler" does whatever is necessary to produce & capture a stream of TAP from the raw source, and package it up in a TAP::Parser::Iterator for the parser to consume.

"SourceHandlers" must implement the source detection & handling interface used by TAP::Parser::IteratorFactory. At 2 methods, the interface is pretty simple: "can_handle" and "make_source".

Unless you're writing a new TAP::Parser::SourceHandler, a plugin, or subclassing TAP::Parser, you probably won't need to use this module directly.

# METHODS

## Class Methods

"can_handle"

Abstract method.

      my $vote = $class->can_handle( $source );

$source is a TAP::Parser::Source.

Returns a number between 0 & 1 reflecting how confidently the raw source can be handled. For example, 0 means the source cannot handle it, 0.5 means it may be able to, and 1 means it definitely can. See "detect_source" in TAP::Parser::IteratorFactory for details on how this is used.

"make_iterator"

Abstract method.

      my $iterator = $class->make_iterator( $source );

$source is a TAP::Parser::Source.

Returns a new TAP::Parser::Iterator object for use by the TAP::Parser. "croak"s on error.

# SUBCLASSING

Please see "SUBCLASSING" in TAP::Parser for a subclassing overview, and any of the subclasses that ship with this module as an example. What follows is a quick overview.

Start by familiarizing yourself with TAP::Parser::Source and TAP::Parser::IteratorFactory. TAP::Parser::SourceHandler::RawTAP is the easiest sub-class to use as an example.

It's important to point out that if you want your subclass to be automatically used by TAP::Parser you'll have to and make sure it gets loaded somehow. If you're using prove you can write an App::Prove plugin. If you're using TAP::Parser or TAP::Harness directly (e.g. through a custom script, ExtUtils::MakeMaker, or Module::Build) you can use the "config" option which will cause "load_sources" in TAP::Parser::IteratorFactory to load your subclass).

Don't forget to register your class with "register_handler" in TAP::Parser::IteratorFactory.

## Example

      package MySourceHandler;
      use strict;
      use MySourceHandler; # see TAP::Parser::SourceHandler
      use TAP::Parser::IteratorFactory;
      use base 'TAP::Parser::SourceHandler';
      TAP::Parser::IteratorFactory->register_handler( __PACKAGE__ );
      sub can_handle {
          my ( $class, $src ) = @_;
          my $meta   = $src->meta;
          my $config = $src->config_for( $class );
          if ($config->{accept_all}) {
              return 1.0;
          } elsif (my $file = $meta->{file}) {
              return 0.0 unless $file->{exists};
              return 1.0 if $file->{lc_ext} eq '.tap';
              return 0.9 if $file->{shebang} && $file->{shebang} =~ /^#!.+tap/;
              return 0.5 if $file->{text};
              return 0.1 if $file->{binary};
          } elsif ($meta->{scalar}) {
              return 0.8 if $$raw_source_ref =~ /\d\.\.\d/;
              return 0.6 if $meta->{has_newlines};
          } elsif ($meta->{array}) {
              return 0.8 if $meta->{size} < 5;
              return 0.6 if $raw_source_ref->[0] =~ /foo/;
              return 0.5;
          } elsif ($meta->{hash}) {
              return 0.6 if $raw_source_ref->{foo};
              return 0.2;
          }
          return 0;
      }
      sub make_iterator {
          my ($class, $source) = @_;
          # this is where you manipulate the source and
          # capture the stream of TAP in an iterator
          # either pick a TAP::Parser::Iterator::* or write your own...
          my $iterator = TAP::Parser::Iterator::Array->new([ 'foo', 'bar' ]);
          return $iterator;
      }
      1;

# AUTHORS

TAPx Developers.

Source detection stuff added by Steve Purkis

# SEE ALSO

TAP::Object, TAP::Parser, TAP::Parser::Source, TAP::Parser::Iterator, TAP::Parser::IteratorFactory, TAP::Parser::SourceHandler::Executable, TAP::Parser::SourceHandler::Perl, TAP::Parser::SourceHandler::File, TAP::Parser::SourceHandler::Handle, TAP::Parser::SourceHandler::RawTAP

2025-01-28 | perl v5.40.1