MooX::StrictConstructor(3p)

NAME
MooX::StrictConstructor - Make your Moo-based object constructors blow up on unknown attributes

SYNOPSIS
    package My::Class;

    use Moo;
    use MooX::StrictConstructor;

    has 'size' => ( is => 'rw' );

    # then somewhere else, when constructing a new instance
    # of My::Class ...

    # this blows up because color is not a known attribute
    My::Class->new( size => 5, color => 'blue' );

DESCRIPTION
Simply loading this module makes your constructors "strict". If your constructor is called with an attribute init argument that your class does not declare, then it dies. This is a great way to catch small typos.

  STANDING ON THE SHOULDERS OF ...
This module was inspired by MooseX::StrictConstructor, and includes some implementation details taken from it.

  SUBVERTING STRICTNESS
There are two options for subverting the strictness to handle problematic arguments. They can be handled in "BUILDARGS" or in "BUILD".

You can use a "BUILDARGS" function to handle them, e.g. this will allow you to pass in a parameter called "spy" without raising an exception. Useful? Only you can tell.

   sub BUILDARGS {
       my ($self, %params) = @_;
       my $spy = delete $params{spy};
       # do something useful with the spy param
       return \%params;
   }

It is also possible to handle extra parameters in "BUILD". This requires the strictness check to be performed at the end of object construction rather than at the beginning.

    use MooX::StrictConstuctor -late;

    sub BUILD {
        my ($self, $params) = @_;
        if ( my $spy = delete $params->{spy} ) {
            # do something useful
        }
    }

When using this option, the object will be fully constructed before checking the parameters, and a failure will cause the destructor to be run.

BUGS/ODDITIES

  Inheritance
A class that uses MooX::StrictConstructor but extends a non-Moo class will not be handled properly. This code hooks into the constructor as it is being strung up (literally) and that happens in the parent class, not the one using strict.

A class that inherits from a Moose based class will discover that the Moose class's attributes are disallowed. Given sufficient Moose meta knowledge it might be possible to work around this. I'd appreciate pull requests and or an outline of a solution.

  Interactions with namespace::clean
MooX::StrictConstructor creates a "new" method that namespace::clean will over-zealously clean. Workarounds include using namespace::autoclean, using MooX::StrictConstructor after namespace::clean or telling namespace::clean to ignore "new" with something like:

  use namespace::clean -except => ['new'];

SEE ALSO

•   MooseX::StrictConstructor

BUGS
Please report any bugs or feature requests on the bugtracker website <https://rt.cpan.org/Public/Dist/Display.html?Name=MooX-StrictConstructor> or by email to bug-MooX-StrictConstructor@rt.cpan.org <mailto:bug-MooX-StrictConstructor@rt.cpan.org>.

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
George Hartzell <hartzell@cpan.org>

CONTRIBUTORS

•   George Hartzell <hartzell@alerce.com>

•   Graham Knop <haarg@haarg.org>

•   JJ Merelo <jjmerelo@gmail.com>

•   jrubinator <jjrs.pam+github@gmail.com>

•   mohawk2 <mohawk2@users.noreply.github.com>

•   Samuel Kaufman <samuel.c.kaufman@gmail.com>

•   Tim Bunce <Tim.Bunce@pobox.com>

COPYRIGHT AND LICENSE
This software is copyright (c) 2013 by George Hartzell.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.