NAME¶
MooseX::AttributeShortcuts - Shorthand for common attribute options
VERSION¶
This document describes version 0.010 of MooseX::AttributeShortcuts - released
April 06, 2012 as part of MooseX-AttributeShortcuts.
SYNOPSIS¶
package Some::Class;
use Moose;
use MooseX::AttributeShortcuts;
# same as:
# is => 'ro', lazy => 1, builder => '_build_foo'
has foo => (is => 'lazy');
# same as: is => 'ro', writer => '_set_foo'
has foo => (is => 'rwp');
# same as: is => 'ro', builder => '_build_bar'
has bar => (is => 'ro', builder => 1);
# same as: is => 'ro', clearer => 'clear_bar'
has bar => (is => 'ro', clearer => 1);
# same as: is => 'ro', predicate => 'has_bar'
has bar => (is => 'ro', predicate => 1);
# works as you'd expect for "private": predicate => '_has_bar'
has _bar => (is => 'ro', predicate => 1);
# extending? Use the "Shortcuts" trait alias
extends 'Some::OtherClass';
has '+bar' => (traits => [Shortcuts], builder => 1, ...);
# or...
package Some::Other::Class;
use Moose;
use MooseX::AttributeShortcuts -writer_prefix => '_';
# same as: is => 'ro', writer => '_foo'
has foo => (is => 'rwp');
DESCRIPTION¶
Ever find yourself repeatedly specifying writers and builders, because there's
no good shortcut to specifying them? Sometimes you want an attribute to have a
read-only public interface, but a private writer. And wouldn't it be easier to
just say "builder => 1" and have the attribute construct the
canonical "_build_$name" builder name for you?
This package causes an attribute trait to be applied to all attributes defined
to the using class. This trait extends the attribute option processing to
handle the above variations.
USAGE¶
This package automatically applies an attribute metaclass trait. Unless you want
to change the defaults, you can ignore the talk about "prefixes"
below.
EXTENDING A CLASS¶
If you're extending a class and trying to extend its attributes as well, you'll
find out that the trait is only applied to attributes defined locally in the
class. This package exports a trait shortcut function "Shortcuts"
that will help you apply this to the extended attribute:
has '+something' => (traits => [Shortcuts], ...);
PREFIXES¶
We accept two parameters on the use of this module; they impact how builders and
writers are named.
-writer_prefix¶
use MooseX::::AttributeShortcuts -writer_prefix => 'prefix';
The default writer prefix is '_set_'. If you'd prefer it to be something else
(say, '_'), this is where you'd do that.
-builder_prefix¶
use MooseX::::AttributeShortcuts -builder_prefix => 'prefix';
The default builder prefix is '_build_', as this is what lazy_build does, and
what people in general recognize as build methods.
NEW ATTRIBUTE OPTIONS¶
Unless specified here, all options defined by Moose::Meta::Attribute and
Class::MOP::Attribute remain unchanged.
Want to see additional options? Ask, or better yet, fork on GitHub and send a
pull request.
For the following, "$name" should be read as the attribute name; and
the various prefixes should be read using the defaults.
is => 'rwp'¶
Specifying "is => 'rwp'" will cause the following options to be
set:
is => 'ro'
writer => "_set_$name"
is => 'lazy'¶
Specifying "is => 'lazy'" will cause the following options to be
set:
is => 'ro'
builder => "_build_$name"
lazy => 1
NOTE: Since 0.009 we no longer set "init_arg => undef" if no
"init_arg" is explicitly provided. This is a change made in parallel
with Moo, based on a large number of people surprised that lazy also made
one's "init_def" undefined.
is => 'lazy', default => ...¶
Specifying "is => 'lazy'" and a default will cause the following
options to be set:
is => 'ro'
lazy => 1
default => ... # as provided
That is, if you specify "is => 'lazy'" and also provide a
"default", then we won't try to set a builder, as well.
builder => 1¶
Specifying "builder => 1" will cause the following options to be
set:
builder => "_build_$name"
clearer => 1¶
Specifying "clearer => 1" will cause the following options to be
set:
clearer => "clear_$name"
or, if your attribute name begins with an underscore:
clearer => "_clear$name"
(that is, an attribute named "_foo" would get "_clear_foo")
predicate => 1¶
Specifying "predicate => 1" will cause the following options to be
set:
predicate => "has_$name"
or, if your attribute name begins with an underscore:
predicate => "_has$name"
(that is, an attribute named "_foo" would get "_has_foo")
trigger => 1¶
Specifying "trigger => 1" will cause the attribute to be created
with a trigger that calls a named method in the class with the options passed
to the trigger. By default, the method name the trigger calls is the name of
the attribute prefixed with "_trigger_".
e.g., for an attribute named "foo" this would be equivalent to:
trigger => sub { shift->_trigger_foo(@_) }
For an attribute named "_foo":
trigger => sub { shift->_trigger__foo(@_) }
This naming scheme, in which the trigger is always private, is the same as the
builder naming scheme (just with a different prefix).
SOURCE¶
The development version is on github at
http://github.com/RsrchBoy/moosex-attributeshortcuts
<
http://github.com/RsrchBoy/moosex-attributeshortcuts> and may be cloned
from
git://github.com/RsrchBoy/moosex-attributeshortcuts.git
<
git://github.com/RsrchBoy/moosex-attributeshortcuts.git>
BUGS¶
Please report any bugs or feature requests on the bugtracker website
https://github.com/RsrchBoy/moosex-attributeshortcuts/issues
When submitting a bug or request, please include a test-file or a patch to an
existing test-file that illustrates the bug or desired feature.
AUTHOR¶
Chris Weyl <cweyl@alumni.drew.edu>
COPYRIGHT AND LICENSE¶
This software is Copyright (c) 2011 by Chris Weyl.
This is free software, licensed under:
The GNU Lesser General Public License, Version 2.1, February 1999