X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=moose-class%2Fslides%2Findex.html;h=f271e011105a567e0a1171cc38f8cc94687416b7;hb=HEAD;hp=8c2da0181f62c5bfee9d6452123ad48866b63f39;hpb=db5e6ae764cca3eb3ac0f318be4c9d45f3ac5437;p=gitmo%2Fmoose-presentations.git
diff --git a/moose-class/slides/index.html b/moose-class/slides/index.html
index 8c2da01..f271e01 100644
--- a/moose-class/slides/index.html
+++ b/moose-class/slides/index.html
@@ -52,7 +52,7 @@ img#me05 {top: 43px;left: 36px;}
Introduction to Moose
- Dave Rolsky
+ Dave Rolsky
@@ -71,7 +71,7 @@ img#me05 {top: 43px;left: 36px;}
- Declarative OO sugar
- Introspectable
- - Extensible (188 MooseX::* on CPAN)
+ - Extensible (202 MooseX::* on CPAN)
- Community approved (1200+ downstream dependents on CPAN)
@@ -950,10 +950,10 @@ sub BUILD {
Object Construction a la Moose
-
Person->new(@_)
+
Person->new(@args)
- - Calls
Person->BUILDARGS(@_)
to turn @_
into a hashref
+ - Calls
Person->BUILDARGS(@args)
to turn @args
into a hashref
- Blesses a reference
- Populates attributes based on the hashref from #1
- Calls
$new_object->BUILDALL($constructor_args)
@@ -1032,7 +1032,7 @@ extends 'LWP';
- No
DEMOLISH()
- - But see
MooseX::NonMoose
for a workaround
+ - But
MooseX::NonMoose
fixes all of this
@@ -1069,7 +1069,7 @@ use Moose;
- Mostly like
$self->SUPER::work(@_)
- But cannot change
@_
!
- - Binds the parent's method at compile time
+ - Binds the parent's method correctly at compile time
- Parent determined by checking
Child->meta()->superclasses()
@@ -1155,8 +1155,8 @@ Person->can('extends');
Cleaning Up Moose Droppings
package Person;
-use namespace::autoclean;
use Moose;
+use namespace::autoclean;
...
@@ -1234,8 +1234,6 @@ use Moose;
# perl bin/prove -lv t/00-prereq.t
-# perl install-moose (if needed)
-
## Read the instructions in t/01-classes.t
# perl bin/prove -lv t/01-classes.t
@@ -1309,23 +1307,25 @@ sub print {
package Person;
use Moose;
-with 'HasPermissions';
+with 'Printable';
Classes Consume Roles
-
my $person = Person->new(
+package Person;
+
+sub as_string { $_[0]->first_name() }
+
+...
+
+my $person = Person->new(
first_name => 'Kenichi',
last_name => 'Asai',
access_level => 42,
);
-print $person->full_name
- . ' has '
- . $person->can_access(42)
- ? 'great power'
- : 'little power';
+$person->print();
@@ -1342,7 +1342,9 @@ print $person->full_name
package Person;
use Moose;
-with 'Printable';
+
with 'Printable';
+
+sub as_string { $_[0]->first_name() }
@@ -1353,6 +1355,8 @@ use Moose;
with 'Printable';
+sub as_string { $_[0]->first_name() }
+
has has_been_printed => ( is => 'rw' );
sub print {
@@ -1481,34 +1485,6 @@ Integer->does('Comparable'); # also true!
-
Name Conflicts Between Roles
-
-
package HasSubProcess;
-use Moose::Role;
-
-sub execute { ... }
-
-package Killer;
-use Moose::Role;
-
-with 'HasSubProcess';
-
-sub execute { ... }
-
-
-
-
Delayed Conflict
-
-
package SysadminAssassin;
-with 'Killer';
-
-
- SysadminAssassin
must implement its own execute
- - But loading the
Killer
role by itself does not cause an error
-
-
-
-
Roles as Interfaces
@@ -1658,8 +1634,6 @@ requires 'compare';
Real Examples
- - Column and ColumnAlias both do ColumnLike
- - ColumnLike things can be used in certain parts of queries
- All queries do HasWhereClause
- Select does Comparable and Selectable (for subselects)
- A where clause requires its components to do Comparable
@@ -1721,6 +1695,15 @@ has 'is_ripped' => ( is => 'rw' );
+
Read-only vs Read-write
+
+
+ - Read-only is preferred
+ - Minimize state in your application
+
+
+
+
Required-ness
@@ -1806,6 +1789,7 @@ use Moose;
has bank => (
is => 'rw',
+ # THIS WILL NOT WORK
default => Bank->new(
name => 'Spire FCU' ),
);
@@ -1828,22 +1812,6 @@ has packages => (
-
What if I Want to Share?
-
-
package Person;
-use Moose;
-
-my $highlander_bank =
- Bank->new(
- name => 'Clan MacLeod Trust' );
-
-has bank => (
- is => 'rw',
- default => sub { $highlander_bank },
-);
-
-
-
Builder
@@ -2033,6 +2001,26 @@ Person->new( shoes => Shoes->new );
+
Some More init_arg
examples
+
+
+ - Private attribute, public constructor name
+
+
+
package Person;
+use Moose;
+
+has _size => (
+ is => 'ro',
+ init_arg => 'size',
+);
+
+my $person = Person->new( size => 42 );
+
+$person->size(); # error
+
+
+
Why Set init_arg => undef
?
@@ -2047,16 +2035,8 @@ Person->new( shoes => Shoes->new );
Attribute Inheritance
- - By default, subclasses inherit attribute as-is
- - Can change some attribute parameters in subclasses
-
- - default
- - builder
- - required
- - lazy
- - others we've not yet covered
-
-
+ - By default, subclasses inherit attributes as-is
+ - Can change attribute parameters in subclasses
@@ -2409,62 +2389,6 @@ around run => sub {
-
Augment and Inner
-
-
- - Inverted
super
- - From least- to most-specific
- - Like Mason's autohandler feature
- - Grandparent to parent to child
- - Not allowed in roles
-
-
-
-
-
Augment and Inner
-
-
package Document;
-
-sub xml { '<doc>' . inner() . '</doc>' }
-
-package Report;
-extends 'Document';
-augment xml =>
- sub { my $self = shift;
- $self->title() . inner() . $self->summary() };
-
-package TPSReport;
-extends 'Report';
-augment xml =>
- sub { my $self = shift;
- $self->tps_xml() . inner() };
-
-
-
-
Augment and Inner
-
-
- - When we call
$tps->xml
...
-
- Document->xml
- Report->xml
- TPSReport->xml
-
-
-
-
-
-
-
Augment and Inner Usage
-
-
- - Call
inner()
to "fill in the blank"
- - Requires designing for subclassing
- - Call
inner()
in the terminal class, just in case
-
-
-
-
Method Modifiers Summary
@@ -2490,21 +2414,7 @@ extends 'Report';
- not call the original method at all (or call a different method)
-
-
-
-
-
Method Modifiers Summary
-
-
- When using modifiers in a role, require the modified method
- - Use
augment
and inner
to invert the normal subclassing flow ...
-
- - Least- to most-specific (parents to children)
- - Build in "insertability" (stick more stuff in the "middle")
-
-
- - Always call
inner
in the most specific subclass to allow for future extension
@@ -2710,11 +2620,15 @@ has start_date => (
Subtype Shortcuts - class_type
use Moose::Util::TypeConstraints;
-class_type 'DateTime';
+
+class_type 'DateTime';
+
+
-subtype 'DateTime',
+
+subtype 'DateTime',
as 'Object',
where { $_->isa('DateTime') },
message { ... };
@@ -2724,11 +2638,15 @@ class_type 'DateTime';
Subtype Shortcuts - role_type
use Moose::Util::TypeConstraints;
-role_type 'Printable';
+
+role_type 'Printable';
+
+
-subtype 'Printable',
+
+subtype 'Printable',
as 'Object',
where
{ Moose::Util::does_role(
@@ -2740,11 +2658,15 @@ role_type 'Printable';
Subtype Shortcuts - duck_type
use Moose::Util::TypeConstraints;
-duck_type Car => qw( run break_down );
+
+duck_type Car => qw( run break_down );
+
+
-subtype 'Car',
+
+subtype 'Car',
as 'Object',
where { all { $_->can($_) }
qw( run break_down ) },
@@ -2755,11 +2677,15 @@ duck_type Car => qw( run break_down );
Subtype Shortcuts - enum
use Moose::Util::TypeConstraints;
-enum Color => qw( red blue green );
+
+enum Color => qw( red blue green );
+
+
-my %ok = map { $_ => 1 }
+
+my %ok = map { $_ => 1 }
qw( red blue green );
subtype 'Color'
@@ -2774,7 +2700,9 @@ subtype 'Color'
package Person;
my $posint =
- subtype as 'Int', where { $_ > 0 };
+ subtype
+ as 'Int',
+ where { $_ > 0 };
has size => (
is => 'ro',
@@ -2833,7 +2761,8 @@ coerce 'My::DateTime',
Coercion Examples
-
coerce 'ArrayRef[Int]',
+ # BAD CODE - DO NOT COPY
+coerce 'ArrayRef[Int]',
from 'Int',
via { [ $_ ] };
@@ -2931,7 +2860,7 @@ sub work {
Digression: The Type Registry
- - Types are actually
Moose::Meta::TypeConstraints
objects
+ - Types are actually
Moose::Meta::TypeConstraint
objects
- Stored in an interpreter-global registry mapping names to objects
@@ -3053,10 +2982,21 @@ has transaction_history => (
+
Specio
+
+
+ - My attempt to replace
MooseX::Types
and built-in types
+ - Third-system effect?
+ - Still alpha - needs some work
+
+
+
+
Recommendation
- - Use
MooseX::Types
+ - Use
MooseX::Types
for now
+ - Switch to
Specio
when it's ready?
- Compile time error catching and automatic namespacing are huge wins
- Docs from
Moose::Util::TypeConstraints
are 98% compatible with MooseX::Types
anyway
- A function exported by a type library works wherever a type name would
@@ -3218,6 +3158,25 @@ has lungs => (
+
Delegation Explained
+
+
package Person;
+
+has lungs => (
+ is => 'ro',
+ isa => 'Lungs',
+ handles => [ 'inhale', 'exhale' ],
+);
+
+sub inhale {
+ my $self = shift;
+ $self->lungs()->inhale();
+}
+
+sub exhale { ... }
+
+
+
Why Delegation?
@@ -3281,8 +3240,12 @@ has account => (
},
- $person->receive_money
= $person->account->deposit
- $person->give_money
= $person->account->withdraw
+ $person->receive_money
+
+ = $person->account->deposit
+ $person->give_money
+
+ = $person->account->withdraw
@@ -3370,8 +3333,7 @@ has history => (
package Person;
use Moose;
has _favorite_numbers => (
- traits => [ 'Array' ],
- is => 'bare',
+ traits => [ 'Array' ],
isa => 'ArrayRef[Int]',
default => sub { [] },
init_arg => undef,
@@ -3434,7 +3396,7 @@ has account => (
isa => 'BankAccount',
handles => {
receive_100 =>
- [ 'deposit', 100 ]
+ [ 'deposit', 100 ],
give_100 =>
[ 'withdraw', 100 ]
},
@@ -3450,82 +3412,6 @@ $person->account->deposit(100);
-
Traits and Metaclasses
-
-
- - The ultimate in customization
- - Per attribute metaclasses
- - Per attribute roles applied to the attribute metaclass
- - Change the meta-level behavior
-
-
-
-
-
Traits and Metaclasses
-
-
- - The default metaclass is
Moose::Meta::Attribute
- - Controls accessor generation, defaults, delegation, etc.
- - Adding a role to this metaclass (or replacing it) allows for infinite customization
-
-
-
-
-
Traits and Metaclasses
-
-
- - Can add/alter/remove an attribute parameter (from
has
)
- - Can change behavior of created attribute
-
-
-
-
-
Simple Trait Example
-
-
package Person;
-use Moose;
-use MooseX::LabeledAttributes;
-
-has ssn => (
- traits => [ 'Labeled' ],
- is => 'ro',
- isa => 'Str',
- label => 'Social Security Number',
-);
-print Person->meta
- ->get_attribute('ssn')->label;
-
-
-
-
Simple Metaclass Example
-
-
package Person;
-use Moose;
-use MooseX::LabeledAttributes;
-
-has ssn => (
- metaclass =>
- 'MooseX::Meta::Attribute::Labeled',
- is => 'ro',
- isa => 'Str',
- label => 'Social Security Number',
-);
-print Person->meta
- ->get_attribute('ssn')->label;
-
-
-
-
Traits vs Metaclass
-
-
- - Can apply any mix of traits to an attribute
- - But just one metaclass
- - Traits (aka roles) can cooperate
- - Metaclasses require you to pick just one
-
-
-
-
Advanced Attributes Summary
@@ -3533,11 +3419,14 @@ print Person->meta
- Use trigger to do an action post-attribute write
- Use delegations to hide "internal" objects
- Use native delegations to treat Perl types as objects
- - Traits and metaclasses let you extend Moose's core attribute features
+
Questions?
+
+
+
Exercises
# cd exercises
@@ -3568,7 +3457,7 @@ Iterate til this passes all its tests
- Not comprehensive
- - 177 MooseX distributions on CPAN as of 09/21/2010
+ - 188 MooseX distributions on CPAN as of 02/03/2011
- Some of them are crap
@@ -3589,7 +3478,7 @@ Iterate til this passes all its tests
MooseX::Declare
use MooseX::Declare;
-use 5.10.0; # for say
+use 5.12.0; # for say
class Person {
has greeting =>
@@ -3608,7 +3497,7 @@ class Person {
Still experimental-ish, but seeing more and more use
Not a source filter!
Hooks into the Perl parser rather than filtering all your code
- But not supported by PPI
, perltidy
, etc. (yet?)
+ But not supported by PPI
, perltidy
, etc. (yet?)
@@ -3762,12 +3651,13 @@ with HasCollection => { type => 'Int' };
@@ -3776,12 +3666,12 @@ with HasCollection => { type => 'Int' };
@@ -3795,7 +3685,7 @@ with HasCollection => { type => 'Int' };