++ed by:

128 PAUSE users
162 non-PAUSE users.

Sebastian Riedel


Mojo::Base - Minimal base class for Mojo projects


  package Cat;
  use Mojo::Base -base;

  has name => 'Nyan';
  has [qw(age weight)] => 4;

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

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

  package main;
  use Mojo::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;


Mojo::Base is a simple base class for Mojo projects with fluent interfaces.

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

All three forms save a lot of typing.

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

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

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


Mojo::Base implements the following functions, which can be imported with the -base flag or by setting a base class.


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

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


Mojo::Base implements the following methods.


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

Create attribute accessor 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. Accessors can be chained, that means they return their invocant when they are called with an argument.


  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.


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

K combinator, tap into a method chain to perform operations on an object within the chain. The object will be the first argument passed to the callback and is also available as $_.

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

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


Mojolicious, Mojolicious::Guides, http://mojolicio.us.