![Many Possible Stateshas ‘ages’ => ( is => ‘rw’,isa => ‘ArrayRef’,);sub avg_age { my ($self) = @_; my $ages = $self->ages(); return (sum @$ages ) / scalar @$ages;}Possible States:undef[][ … ]if (defined($ages) and @$ages) { … }](https://image.slidesharecdn.com/moosebestpractices-100813165156-phpapp01/85/Moose-Best-Practices-4-320.jpg)
![Many Possible Stateshas ‘ages’ => ( is => ‘rw’,isa => ‘ArrayRef’,default => sub{ [] },);sub avg_age { my ($self) = @_; my $ages = $self->ages(); return (sum @$ages ) / scalar @$ages;}Possible Values:undef [] [ … ]if (@$ages) { … }](https://image.slidesharecdn.com/moosebestpractices-100813165156-phpapp01/85/Moose-Best-Practices-5-320.jpg)
![Many Possible Statessubtype ‘NonEmptyArrayRef' => as ‘ArrayRef’ => where { @$_ > 0 }; has ‘ages’ => ( is => ‘rw’,isa => ‘NonEmptyArrayRef’,required => 1,);sub avg_age { my ($self) = @_; my $ages = $self->ages(); return (sum @$ages ) / scalar @$ages;}Possible Values:undef[] [ … ]…](https://image.slidesharecdn.com/moosebestpractices-100813165156-phpapp01/85/Moose-Best-Practices-7-320.jpg)
![Changing Statehas ‘ages’ => (is => ‘rw’,isa => ‘ArrayRef’, default => sub{ [] },);has ‘avg_age’ => ( is => ‘ro’,isa => ‘Int’,lazy_build => 1,);sub _build_avg_age { my ($self) = @_; my $ages = $self->ages(); return (sum @$ages ) / scalar @$ages;}my $obj = Class->new( ages => [4, 7],);print $obj->avg_age(); # 6$obj->ages([4, 11]);print $obj->avg_age(); # 6!](https://image.slidesharecdn.com/moosebestpractices-100813165156-phpapp01/85/Moose-Best-Practices-12-320.jpg)
![Changing Statehas ‘ages’ => (is => ‘ro’,isa => ‘ArrayRef’, default => sub{ [] },);has ‘avg_age’ => ( is => ‘ro’,isa => ‘Int’,lazy_build => 1,);sub _build_avg_age { my ($self) = @_; my $ages = $self->ages(); return (sum @$ages ) / scalar @$ages;}my $obj = Class->new( ages => [4, 7],);print $obj->avg_age(); # 6$obj->ages([4, 11]);print $obj->avg_age(); # 6!](https://image.slidesharecdn.com/moosebestpractices-100813165156-phpapp01/85/Moose-Best-Practices-13-320.jpg)
Moose Best Practices
- 1. MooseBest Practicesby Aran Deltac (CPAN: bluefeet)
- 3. default => $valuehas ‘is_clean’ => ( is => ‘ro’,isa => ‘Bool’, default => 1,);
- 4. Many Possible Stateshas ‘ages’ => ( is => ‘rw’,isa => ‘ArrayRef’,);sub avg_age { my ($self) = @_; my $ages = $self->ages(); return (sum @$ages ) / scalar @$ages;}Possible States:undef[][ … ]if (defined($ages) and @$ages) { … }
- 5. Many Possible Stateshas ‘ages’ => ( is => ‘rw’,isa => ‘ArrayRef’,default => sub{ [] },);sub avg_age { my ($self) = @_; my $ages = $self->ages(); return (sum @$ages ) / scalar @$ages;}Possible Values:undef [] [ … ]if (@$ages) { … }
- 6. required => 1has ‘ssn’ => ( is => ‘ro’,isa => ‘Str’, required => 1,);
- 7. Many Possible Statessubtype ‘NonEmptyArrayRef' => as ‘ArrayRef’ => where { @$_ > 0 }; has ‘ages’ => ( is => ‘rw’,isa => ‘NonEmptyArrayRef’,required => 1,);sub avg_age { my ($self) = @_; my $ages = $self->ages(); return (sum @$ages ) / scalar @$ages;}Possible Values:undef[] [ … ]…
- 8. builder => $sub_namehas ‘dbh’ => ( is => ‘ro’,isa => ‘dbh’,builder => ‘_build_dbh’,);sub _build_dbh { return DBI->connect(…);}
- 9. lazy => $boolhas ‘dbh’ => ( is => ‘ro’,isa => ‘dbh’, builder => ‘_build_dbh’,lazy => 1,);sub _build_dbh { return DBI->connect(…);}
- 10. lazy_build => 1has ‘dbh’ => ( is => ‘ro’,isa => ‘DBI::db’,lazy_build => 1,);sub _build_dbh { return DBI->connect( … );}
- 11. is => ‘ro’has ‘name’ => ( is => ‘ro’,isa => ‘Str’,);
- 12. Changing Statehas ‘ages’ => (is => ‘rw’,isa => ‘ArrayRef’, default => sub{ [] },);has ‘avg_age’ => ( is => ‘ro’,isa => ‘Int’,lazy_build => 1,);sub _build_avg_age { my ($self) = @_; my $ages = $self->ages(); return (sum @$ages ) / scalar @$ages;}my $obj = Class->new( ages => [4, 7],);print $obj->avg_age(); # 6$obj->ages([4, 11]);print $obj->avg_age(); # 6!
- 13. Changing Statehas ‘ages’ => (is => ‘ro’,isa => ‘ArrayRef’, default => sub{ [] },);has ‘avg_age’ => ( is => ‘ro’,isa => ‘Int’,lazy_build => 1,);sub _build_avg_age { my ($self) = @_; my $ages = $self->ages(); return (sum @$ages ) / scalar @$ages;}my $obj = Class->new( ages => [4, 7],);print $obj->avg_age(); # 6$obj->ages([4, 11]);print $obj->avg_age(); # 6!
- 14. writer => $sub_namehas ‘color’ => ( is => ‘ro’,isa => ‘Str’,write => ‘_color’,);
- 15. init_arg => undefhas ‘result’ => ( is => ‘ro’,isa => ‘HashRef’, writer => ‘_set_result’,init_arg => undef,);