File Coverage

blib/lib/Splunk/Base.pm

Criterion	Covered	Total	%
statement	67	85	78.8
branch	21	42	50.0
condition	5	15	33.3
subroutine	25	27	92.5
pod	4	4	100.0
total	122	173	70.5

package Splunk::Base;

use strict;
use warnings;
use utf8;
use feature ();

# No imports because we get subclassed, a lot!
use Carp         ();
use Scalar::Util ();

# Only Perl 5.14+ requires it on demand
use IO::Handle ();

# Role support requires Role::Tiny 2.000001+
use constant ROLES => !!(eval { require Role::Tiny; Role::Tiny->VERSION('2.000001'); 1 });

# Supported on Perl 5.22+
my $NAME = eval { require Sub::Util; Sub::Util->can('set_subname') } || sub { $_[1] };

# Protect subclasses using AUTOLOAD
sub DESTROY { }

sub _monkey_patch {
  my ($class, %patch) = @_;
  no strict 'refs';
  no warnings 'redefine';
  *{"${class}::$_"} = $NAME->("${class}::$_", $patch{$_}) for keys %patch;
}

sub attr {
  my ($self, $attrs, $value) = @_;
  return unless (my $class = ref $self || $self) && $attrs;

  Carp::croak 'Default has to be a code reference or constant value'
    if ref $value && ref $value ne 'CODE';

  for my $attr (@{ref $attrs eq 'ARRAY' ? $attrs : [$attrs]}) {
    Carp::croak qq{Attribute "$attr" invalid} unless $attr =~ /^[a-zA-Z_]\w*$/;

    # Very performance-sensitive code with lots of micro-optimizations
    if (ref $value) {
      _monkey_patch $class, $attr, sub {
        return exists $_[0]{$attr} ? $_[0]{$attr} : ($_[0]{$attr} = $value->($_[0])) if @_ == 1;
        $_[0]{$attr} = $_[1];
        $_[0];
      };
    }
    elsif (defined $value) {
      _monkey_patch $class, $attr, sub {
        return exists $_[0]{$attr} ? $_[0]{$attr} : ($_[0]{$attr} = $value) if @_ == 1;
        $_[0]{$attr} = $_[1];
        $_[0];
      };
    }
    else {
      _monkey_patch $class, $attr,
        sub { return $_[0]{$attr} if @_ == 1; $_[0]{$attr} = $_[1]; $_[0] };
    }
  }
}

sub import {
  my $class = shift;
  return unless my $flag = shift;

  # Base
  if ($flag eq '-base') { $flag = $class }

  # Strict
  elsif ($flag eq '-strict') { $flag = undef }

  # Module
  elsif ((my $file = $flag) && !$flag->can('new')) {
    $file =~ s!::|'!/!g;
    require "$file.pm";
  }

  # ISA
  if ($flag) {
    my $caller = caller;
    no strict 'refs';
    push @{"${caller}::ISA"}, $flag;
    _monkey_patch $caller, 'has', sub { attr($caller, @_) };
  }

  # Splunk modules are strict!
  $_->import for qw(strict warnings utf8);
  feature->import(':5.10');
}

sub new {
  my $class = shift;
  bless @_ ? @_ > 1 ? {@_} : {%{$_[0]}} : {}, ref $class || $class;
}

sub tap {
  my ($self, $cb) = (shift, shift);
  $_->$cb(@_) for $self;
  return $self;
}

sub with_roles {
  Carp::croak 'Role::Tiny 2.000001+ is required for roles' unless ROLES;
  my ($self, @roles) = @_;

  return Role::Tiny->create_class_with_roles($self,
    map { /^\+(.+)$/ ? "${self}::Role::$1" : $_ } @roles)
    unless my $class = Scalar::Util::blessed $self;

  return Role::Tiny->apply_roles_to_object($self,
    map { /^\+(.+)$/ ? "${class}::Role::$1" : $_ } @roles);
}

1;

=encoding utf8

=head1 NAME

Splunk::Base - Minimal base class (fork of Mojo::Base)

=head1 SYNOPSIS

  package Cat;
  use Splunk::Base -base;

  has name => 'Nyan';
  has ['age', 'weight'] => 4;

  package Tiger;
  use Splunk::Base 'Cat';

  has friend  => sub { Cat->new };
  has stripes => 42;

  package main;
  use Splunk::Base -strict;

  my $mew = Cat->new(name => 'Longcat');
  say $mew->age;
  say $mew->age(3)->weight(5)->age;

  my $rawr = Tiger->new(stripes => 38, weight => 250);
  say $rawr->tap(sub { $_->friend->name('Tacgnol') })->weight;

=head1 DESCRIPTION

L is a simple base class for L projects with fluent
interfaces.

  # Automatically enables "strict", "warnings", "utf8" and Perl 5.10 features
  use Splunk::Base -strict;
  use Splunk::Base -base;
  use Splunk::Base 'SomeBaseClass';

All three forms save a lot of typing.

  # use Splunk::Base -strict;
  use strict;
  use warnings;
  use utf8;
  use feature ':5.10';
  use IO::Handle ();

  # use Splunk::Base -base;
  use strict;
  use warnings;
  use utf8;
  use feature ':5.10';
  use IO::Handle ();
  push @ISA, 'Splunk::Base';
  sub has { Splunk::Base::attr(__PACKAGE__, @_) }

  # use Splunk::Base 'SomeBaseClass';
  use strict;
  use warnings;
  use utf8;
  use feature ':5.10';
  use IO::Handle ();
  require SomeBaseClass;
  push @ISA, 'SomeBaseClass';
  sub has { Splunk::Base::attr(__PACKAGE__, @_) }

=head1 FUNCTIONS

L implements the following functions, which can be imported with
the C<-base> flag or by setting a base class.

=head2 has

  has 'name';
  has ['name1', 'name2', 'name3'];
  has name => 'foo';
  has name => sub {...};
  has ['name1', 'name2', 'name3'] => 'foo';
  has ['name1', 'name2', 'name3'] => sub {...};

Create attributes for hash-based objects, just like the L method.

=head1 METHODS

L implements the following methods.

=head2 attr

  $object->attr('name');
  SubClass->attr('name');
  SubClass->attr(['name1', 'name2', 'name3']);
  SubClass->attr(name => 'foo');
  SubClass->attr(name => sub {...});
  SubClass->attr(['name1', 'name2', 'name3'] => 'foo');
  SubClass->attr(['name1', 'name2', 'name3'] => sub {...});

Create attribute accessors for hash-based objects, an array reference can be
used to create more than one at a time. Pass an optional second argument to set
a default value, it should be a constant or a callback. The callback will be
executed at accessor read time if there's no set value, and gets passed the
current instance of the object as first argument. Accessors can be chained, that
means they return their invocant when they are called with an argument.

=head2 new

  my $object = SubClass->new;
  my $object = SubClass->new(name => 'value');
  my $object = SubClass->new({name => 'value'});

This base class provides a basic constructor for hash-based objects. You can
pass it either a hash or a hash reference with attribute values.

=head2 tap

  $object = $object->tap(sub {...});
  $object = $object->tap('some_method');
  $object = $object->tap('some_method', @args);

Tap into a method chain to perform operations on an object within the chain
(also known as a K combinator or Kestrel). The object will be the first argument
passed to the callback, and is also available as C<$_>. The callback's return
value will be ignored; instead, the object (the callback's first argument) will
be the return value. In this way, arbitrary code can be used within (i.e.,
spliced or tapped into) a chained set of object method calls.

  # Longer version
  $object = $object->tap(sub { $_->some_method(@args) });

  # Inject side effects into a method chain
  $object->foo('A')->tap(sub { say $_->foo })->foo('B');

=head2 with_roles

  my $new_class = SubClass->with_roles('SubClass::Role::One');
  my $new_class = SubClass->with_roles('+One', '+Two');
  $object       = $object->with_roles('+One', '+Two');

Create a new class with one or more L roles. If called on a class
returns the new class, or if called on an object reblesses the object into the
new class. For roles following the naming scheme C you
can use the shorthand C<+RoleName>. Note that role support depends on
L (2.000001+).

  # Create a new class with the role "SubClass::Role::Foo" and instantiate it
  my $new_class = SubClass->with_roles('+Foo');
  my $object    = $new_class->new;

=head1 SEE ALSO

L, L, L

=cut