—package
Mojo::Base;
use
strict;
use
warnings;
use
utf8;
use
feature ();
# No imports because we get subclassed, a lot!
use
Carp ();
# Only Perl 5.14+ requires it on demand
use
IO::Handle ();
sub
import
{
my
$class
=
shift
;
return
unless
my
$flag
=
shift
;
no
strict
'refs'
;
# Base
if
(
$flag
eq
'-base'
) {
$flag
=
$class
}
# Strict
elsif
(
$flag
eq
'-strict'
) {
$flag
=
undef
}
# Module
else
{
my
$file
=
$flag
;
$file
=~ s/::|'/\//g;
require
"$file.pm"
unless
$flag
->can(
'new'
);
}
# ISA
if
(
$flag
) {
my
$caller
=
caller
;
push
@{
"${caller}::ISA"
},
$flag
;
*{
"${caller}::has"
} =
sub
{ attr(
$caller
,
@_
) };
}
# Mojo modules are strict!
strict->
import
;
warnings->
import
;
utf8->
import
;
feature->
import
(
':5.10'
);
}
sub
new {
my
$class
=
shift
;
bless
@_
?
@_
> 1 ? {
@_
} : {%{
$_
[0]}} : {},
ref
$class
||
$class
;
}
# Performance is very important for something as often used as accessors,
# so we optimize them by compiling our own code, don't be scared, we have
# tests for every single case
sub
attr {
my
(
$class
,
$attrs
,
$default
) =
@_
;
return
unless
(
$class
=
ref
$class
||
$class
) &&
$attrs
;
Carp::croak
'Default has to be a code reference or constant value'
if
ref
$default
&&
ref
$default
ne
'CODE'
;
# Compile attributes
for
my
$attr
(@{
ref
$attrs
eq
'ARRAY'
?
$attrs
: [
$attrs
]}) {
Carp::croak
qq{Attribute "$attr" invalid}
unless
$attr
=~ /^[a-zA-Z_]\w*$/;
# Header (check arguments)
my
$code
=
"package $class;\nsub $attr {\n if (\@_ == 1) {\n"
;
# No default value (return value)
unless
(
defined
$default
) {
$code
.=
" return \$_[0]{'$attr'};"
}
# Default value
else
{
# Return value
$code
.=
" return \$_[0]{'$attr'} if exists \$_[0]{'$attr'};\n"
;
# Return default value
$code
.=
" return \$_[0]{'$attr'} = "
;
$code
.=
ref
$default
eq
'CODE'
?
'$default->($_[0]);'
:
'$default;'
;
}
# Store value
$code
.=
"\n }\n \$_[0]{'$attr'} = \$_[1];\n"
;
# Footer (return invocant)
$code
.=
" \$_[0];\n}"
;
# We compile custom attribute code for speed
no
strict
'refs'
;
warn
"-- Attribute $attr in $class\n$code\n\n"
if
$ENV
{MOJO_BASE_DEBUG};
Carp::croak
"Mojo::Base error: $@"
unless
eval
"$code;1"
;
}
}
sub
tap {
my
(
$self
,
$cb
) =
@_
;
$_
->
$cb
for
$self
;
return
$self
;
}
1;
=head1 NAME
Mojo::Base - Minimal base class for Mojo projects
=head1 SYNOPSIS
package Cat;
use Mojo::Base -base;
has name => 'Nyan';
has [qw(birds mice)] => 2;
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->mice;
say $mew->mice(3)->birds(4)->mice;
my $rawr = Tiger->new(stripes => 23, mice => 0);
say $rawr->tap(sub { $_->friend->name('Tacgnol') })->mice;
=head1 DESCRIPTION
L<Mojo::Base> is a simple base class for L<Mojo> projects.
# 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__, @_) }
=head1 FUNCTIONS
L<Mojo::Base> exports the following functions if imported with the C<-base>
flag or a base class.
=head2 has
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 C<attr> method.
=head1 METHODS
L<Mojo::Base> implements the following methods.
=head2 new
my $object = BaseSubClass->new;
my $object = BaseSubClass->new(name => 'value');
my $object = BaseSubClass->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 attr
$object->attr('name');
BaseSubClass->attr('name');
BaseSubClass->attr([qw(name1 name2 name3)]);
BaseSubClass->attr(name => 'foo');
BaseSubClass->attr(name => sub {...});
BaseSubClass->attr([qw(name1 name2 name3)] => 'foo');
BaseSubClass->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 excuted 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.
=head2 tap
$object = $object->tap(sub {...});
K combinator, tap into a method chain to perform operations on an object
within the chain. The object will be the first argument passed to the closure
and is also available via C<$_>.
=head1 DEBUGGING
You can set the MOJO_BASE_DEBUG environment variable to get some advanced
diagnostics information printed to C<STDERR>.
MOJO_BASE_DEBUG=1
=head1 SEE ALSO
L<Mojolicious>, L<Mojolicious::Guides>, L<http://mojolicio.us>.
=cut