Linux Certif

Toute la documentation sur la certification Linux LPI

TAP::Parser::SourceHandler.3pm

NAME

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

VERSION

Version 3.20

SYNOPSIS

   # abstract class - don't use directly!
   # see TAP::Parser::IteratorFactory for general usage
 
   # must be sub-classed for use
   package MySourceHandler;
   use base qw( 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 an 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 (eg. 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 vars '@ISA'; # compat with older perls
 
   use MySourceHandler; # see TAP::Parser::SourceHandler
   use TAP::Parser::IteratorFactory;
 
   @ISA = qw( 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