You're right that the docs are a little sparse in that area. There are some examples though - Moose::Manual::Attributes, Moose::Cookbook::Basics::Point_AttributesAndSubclassing, Moose::Cookbook::Basics::BankAccount_MethodModifiersAndSubclassing, etc. If you don't think this is enough, please submit a bug report.

Out of the box, Moose supports two styles of object construction:

# Key-value pairs
my $point1 = Point->new(x => 10, y => 20);

# Hashref
my $point2 = Point->new({ x => 10, y => 20 });

[download]

In your class it's possible to override BUILDARGS to add your own argument parsing...

use v5.12;

{
    package Point;
    use Moose;
    has 'x' => (is => 'rw', isa => 'Int');
    has 'y' => (is => 'rw', isa => 'Int');
    around BUILDARGS => sub {
        my $orig = shift;
        my $self = shift;
        # Allow object to be built by passing two integers...
        if (@_ == 2 and $_[0] =~ /^[0-9]+$/ and $_[1] =~ /^[0-9]+$/) {
            return { x => $_[0], y => $_[1] };
        }
        # If not two integers, then fall back to standard Moose BUILDA
+RGS...
        return $self->$orig(@_);
    };
    __PACKAGE__->meta->make_immutable;
}

# Use our overridden BUILDARGS...
print Point->new(10, 20)->dump;

# Standard Moose BUILDARGS is fallback...
print Point->new(x => 10, y => 20)->dump;
print Point->new({ x => 10, y => 20 })->dump;

[download]
package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name

In reply to Re: Dear Moose docs... by tobyink
in thread Dear Moose docs... by 7stud

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.