X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=moose-class%2Fslides%2Findex.html;h=7df4bccfed376bb51a3a5ebb063384776b34ad03;hb=cbf2305bcc8357a9450403dc9b24ebdc48c10955;hp=b3fc1414ac85aa9d782f8aa1532cf6a9e9c8976f;hpb=1d40915d1ad2e2a12bc3bbf64a764ffa6f69994a;p=gitmo%2Fmoose-presentations.git
diff --git a/moose-class/slides/index.html b/moose-class/slides/index.html
index b3fc141..7df4bcc 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
@@ -71,7 +71,8 @@ img#me05 {top: 43px;left: 36px;}
- Declarative OO sugar
- Introspectable
- - Extensible (MooseX::* on CPAN)
+ - Extensible (188 MooseX::* on CPAN)
+ - Community approved (1200+ downstream dependents on CPAN)
package Person;
use Moose;
-has first_name => ( is => 'rw' );
+has first_name => ( is => 'ro' );
@@ -218,7 +219,7 @@ use Moose;
- AKA advice
- "Before foo(), do this first"
- - "Do this after foo()
+ - "Do this after foo()"
- "Put this code around foo()"
@@ -300,8 +301,8 @@ has blog_uri => (
handles => { 'blog_host' => 'host' },
);
-$person->blog_host;
-# really calls $person->blog_uri->host
+$person->blog_host;
+# really calls $person->blog_uri->host
@@ -892,8 +893,8 @@ use Moose;
BUILDARGS
- - Takes
@_, returns a hash reference of attribute names/value
- - Accepts a hash or hashref; throws otherwise
+ - Processes
new's @_, returns a hash reference of attribute name/value pairs
+ - Accepts a hash or hashref; errors otherwise
- Provide your own for other cases
- Always call
$class->SUPER::BUILDARGS(@_) as a fallback!
@@ -951,11 +952,11 @@ sub BUILD {
Person->new(@_)
-
+
- Calls
Person->BUILDARGS(@_) to turn @_ into a hashref
- Blesses a reference
- Populates attributes based on the hashref from #1
- - Calls
$new_object->BUILDALL($constructor_args)
+ - Calls
$new_object->BUILDALL($constructor_args)
... which calls all BUILD methods
- Returns the object
@@ -967,6 +968,7 @@ sub BUILD {
- Technically it's a hash reference
- If you ever treat it as one you are doing it wrong!
+ - Moose probably provides a feature to do what you need
- Like
DESTROY, but Moose makes sure all DEMOLISH methods in a hierarchy are called
- Called in normal inheritance order, children to parents
+ - Never called by you, only by Perl itself
@@ -1039,6 +1042,7 @@ extends 'LWP';
override is another method modifier- An alternative to Perl's
SUPER::
+ - Declares your intent to override a method
@@ -1050,13 +1054,13 @@ use Moose;
extends 'Person';
-override work => sub {
+override work => sub {
my $self = shift;
die "Pay me first"
unless $self->got_paid;
- super();
-};
+ super();
+};
@@ -1065,7 +1069,8 @@ 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()
- Not very hygienic
@@ -1141,17 +1145,31 @@ use Moose;
...
-no Moose;
+no Moose;
# false
-Person->can('extends');
+Person->can('extends');
+
+
+
+
Cleaning Up Moose Droppings
+
+
package Person;
+use namespace::autoclean;
+use Moose;
+
+...
+
+# false
+Person->can('extends');
No Moose
- no Moose at the end of a package is a best practice- Cleaning up is a best practice
+ - Say
no Moose at the end of a package
- Or
use namespace::autoclean at the top
- Just do it
@@ -1161,13 +1179,13 @@ Person->can('extends');
Immutability
- - Stevan's Incantation of Fleet-Footedness
+ - Stevan's Incantation of Fleet-Footedness
package Person;
use Moose;
-__PACKAGE__->meta->make_immutable;
+
__PACKAGE__->meta->make_immutable;
@@ -1218,6 +1236,8 @@ use Moose;
# perl install-moose (if needed)
+## Read the instructions in t/01-classes.t
+
# perl bin/prove -lv t/01-classes.t
# edit lib/Person.pm and lib/Employee.pm
@@ -1289,23 +1309,25 @@ 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();
@@ -1322,7 +1344,9 @@ print $person->full_name
package Person;
use Moose;
-with 'Printable';
+
with 'Printable';
+
+sub as_string { $_[0]->first_name() }
@@ -1333,6 +1357,8 @@ use Moose;
with 'Printable';
+sub as_string { $_[0]->first_name() }
+
has has_been_printed => ( is => 'rw' );
sub print {
@@ -1353,7 +1379,7 @@ sub print {
# or ...
-Person->meta->does('Printable')
+Person->meta->does_role('Printable')
@@ -1413,69 +1439,17 @@ use Moose;
-
Method Aliasing
-
-
package FragileDancer;
-use Moose;
-
-with 'IsFragile' =>
- { -alias =>
- { break => 'break_bone' } },
- 'CanBreakdance' =>
- { -alias =>
- { break => 'break_it_down' } };
-
-
- - Renames the roles' methods
- - Still conflicts, need to
exclude as well
-
-
-
Method Exclusion
-
-
package FragileDancer;
-use Moose;
-
-with 'IsFragile' =>
- { -alias =>
- { break => 'break_bone' },
- -excludes => 'break' },
- 'CanBreakdance' =>
- { -alias =>
- { break => 'break_it_down' },
- -excludes => 'break' };
-
-
And then ...
-
-
package FragileDancer;
-use Moose;
-
-sub break {
- my $self = shift;
-
- $self->break_it_down;
- if ( rand(1) < 0.5 ) {
- $self->break_bone;
- }
-}
-
-
Still Full of Fail
+
Conflicts Are a Smell
- - Roles are also about semantics!
- - We've fulfilled the letter and lost the spirit
+ - Roles are about semantics!
- Roles have a meaning
- - Think twice before blindly aliasing and excluding methods!
+ - Method name conflicts smell like bad design
-
Hot Role-on-Role Action
+
Roles With Roles
package Comparable;
use Moose::Role;
@@ -1484,7 +1458,7 @@ requires 'compare';
-
Hot Role-on-Role Action
+
Roles With Roles
package TestsEquality;
use Moose::Role;
@@ -1493,7 +1467,7 @@ with 'Comparable';
sub is_equal {
my $self = shift;
- return $self->compare(@_) == 0;
+ return $self->compare(@_) == 0;
}
@@ -1531,11 +1505,11 @@ with 'HasSubProcess';
Delayed Conflict
-
package StateOfTexas;
+ package SysadminAssassin;
with 'Killer';
- StateOfTexas must implement its own executeSysadminAssassin must implement its own execute- But loading the
Killer role by itself does not cause an error
@@ -1563,7 +1537,7 @@ use Moose;
with 'HasSize';
-has size => ( is => 'ro' );
+has size => ( is => 'ro' );
@@ -1577,7 +1551,7 @@ requires 'size';
package Shirt;
use Moose;
-has size => ( is => 'ro' );
+has size => ( is => 'ro' );
with 'HasSize';
@@ -1599,9 +1573,9 @@ with 'HasSize';
package Comparison;
use Moose;
-has [ 'left', 'right' ] => (
- is => 'ro',
- does => 'Comparable',
+has [ 'left', 'right' ] => (
+ is => 'ro',
+ does => 'Comparable',
);
@@ -1616,7 +1590,7 @@ has [ 'left', 'right' ] => (
use Moose::Util qw( apply_all_roles );
-my $fragile_person = Person->new( ... );
+my $fragile_person = Person->new( ... );
apply_all_roles( $fragile_person,
'IsFragile' );
@@ -1690,8 +1664,6 @@ 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
@@ -1772,8 +1744,8 @@ has first_name => (
required => 1,
);
-Person->new( first_name => undef ); # ok
-Person->new(); # kaboom
+Person->new( first_name => undef ); # ok
+Person->new(); # kaboom
@@ -1838,6 +1810,7 @@ use Moose;
has bank => (
is => 'rw',
+ # THIS WILL NOT WORK
default => Bank->new(
name => 'Spire FCU' ),
);
@@ -1866,7 +1839,8 @@ has packages => (
use Moose;
my $highlander_bank =
- Bank->new( name => 'Spire FCU' );
+ Bank->new(
+ name => 'Clan MacLeod Trust' );
has bank => (
is => 'rw',
@@ -1878,7 +1852,8 @@ has bank => (
Builder
- - A method name which returns the default
+ - A method name
+ - When called, this method returns the default value
has shoes => (
is => 'ro',
lazy => 1,
- builder => '_build_shoes',
+ builder => '_build_shoes',
);
sub _build_shoes {
@@ -2035,16 +2011,16 @@ has account => (
package Person;
use Moose;
-has shoe_size => (
+has shoe_size => (
is => 'ro',
init_arg => 'foot_size',
);
-Person->new( shoe_size => 13 );
+Person->new( shoe_size => 13 );
my $person =
- Person->new( foot_size => 13 );
-print $person->shoe_size;
+ Person->new( foot_size => 13 );
+print $person->shoe_size;
@@ -2053,12 +2029,12 @@ print $person->shoe_size;
package Person;
use Moose;
-has shoes => (
+has shoes => (
is => 'ro',
init_arg => undef,
);
-Person->new( shoes => Shoes->new );
+Person->new(
shoes => Shoes->new );
@@ -2205,6 +2181,13 @@ has first_name => (
Attributes can have a default or builder
Attributes with a default or builder can be lazy
Attributes can have a clearer and/or predicate
+
+
+
+
+
Basic Attributes Summary
+
+
- An attribute's constructor name can be changed with
init_arg
- A subclass can alter its parents' attributes
- Attribute accessor names can be changed
@@ -2234,18 +2217,18 @@ Iterate til this passes all its tests
- Apply to an existing method
- - ... from a parent class, the current class, or a role
+ - ... that comes from a parent class, the current class, or a role
- Roles can provide modifiers that are applied at composition time
-
What is a Method Modifier
+
What Are Method Modifiers For?
- "Inject" behavior
- Add behavior to generated methods (accessors, delegations)
- - Provide roles which modify existing behavior
+ - Added from a role, can modify existing behavior
- Inverted
super
- From least- to most-specific
+ - Like Mason's autohandler feature
- Grandparent to parent to child
- Not allowed in roles
@@ -2444,19 +2428,21 @@ around run => sub {
Augment and Inner
-
package Document;
+ package Document;
sub xml { '<doc>' . inner() . '</doc>' }
package Report;
extends 'Document';
augment xml =>
- sub { title() . inner() . summary() };
+ sub { my $self = shift;
+ $self->title() . inner() . $self->summary() };
package TPSReport;
extends 'Report';
augment xml =>
- sub { tps_xml() . inner() };
+ sub { my $self = shift;
+ $self->tps_xml() . inner() };
@@ -2578,11 +2564,11 @@ Item
Undef
Defined
Value
- Str
- Num
- Int
- ClassName
- RoleName
+ Str
+ Num
+ Int
+ ClassName
+ RoleName
@@ -2600,7 +2586,7 @@ Item
CodeRef
RegexpRef
GlobRef
- FileHandle
+ FileHandle
Object
@@ -2609,15 +2595,12 @@ Item
Bool
True
- 1
-924.1
-'true'
-{}
+ 1
False
0
-0.0
'0'
+''
undef
@@ -2631,6 +2614,7 @@ undef
Value is true when ! ref $thingValue and Str are effectively the same, but Str is more expressiveNum is true when a $scalar looks like a number- An overloaded object which numifies does not pass the
Num constraint!
- Perl 5's overloading is hopelessly broken
@@ -2731,9 +2715,11 @@ 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 { ... };
@@ -2743,10 +2729,12 @@ subtype 'DateTime',
Subtype Shortcuts - role_type
use Moose::Util::TypeConstraints;
-role_type 'Printable';
+role_type 'Printable';
-subtype 'Printable',
- as 'Object',
+
+
+subtype 'Printable',
+ as 'Object',
where
{ Moose::Util::does_role(
$_, 'Printable' ) },
@@ -2757,9 +2745,11 @@ subtype '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 ) },
@@ -2770,12 +2760,14 @@ subtype 'Car',
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'
+subtype 'Color'
as 'Str',
where { $ok{$_} },
message { ... };
@@ -2891,6 +2883,19 @@ no Moose;
+
Questions So Far?
+
+
+
+
Exercises
+
+
# cd exercises
+# perl bin/prove -lv t/05-types.t
+
+Iterate til this passes all its tests
+
Typed Methods (Low-tech)
package Person;
@@ -3021,9 +3026,9 @@ coerce ArrayOfInt
use MyApp::Types qw( ArrayOfInt );
-has transaction_history => (
- is => 'rw',
- isa => ArrayOfInt,
+has transaction_history => (
+ is => 'rw',
+ isa => ArrayOfInt,
);
@@ -3033,7 +3038,7 @@ has transaction_history => (
- Type names are exported functions, catches typos early
- Types must be pre-declared
- - Types are stored with namespaces internally, but externally are short
+ - Types are stored with namespaces internally, but you use short names
- Import existing Moose types as functions from
MooseX::Types::Moose
- Still need string names for things like
ArrayRef['Email::Address']
@@ -3046,7 +3051,7 @@ has transaction_history => (
Catches typos at compile time
Automatic namespacing
One more thing to install and learn
- Every name gets types twice (declared and then defined)
+ Every name is typed twice (declared and then defined)
Still stuck with strings when referring to class or role names
Coercion gotcha from earlier still applies to types exported from MooseX::Types::Moose
@@ -3067,15 +3072,6 @@ has transaction_history => (
Questions?
-
-
Exercises
-
-
# cd exercises
-# perl bin/prove -lv t/05-types.t
-
-Iterate til this passes all its tests
-
Part 6: Advanced Attributes
@@ -3173,7 +3169,7 @@ $alice->friend($bob);
after salary_level => {
my $self = shift;
- return unless @_;
+ return unless @_;
$self->clear_salary;
};
@@ -3185,11 +3181,22 @@ $alice->friend($bob);
has salary_level => (
is => 'rw',
- trigger => sub { $_[0]->clear_salary },
+ trigger =>
+ sub { $_[0]->clear_salary },
);
+
Trigger Arguments
+
+
+ $self$new_value$old_value - if one exists
+
Delegation
@@ -3205,7 +3212,7 @@ $alice->friend($bob);
has lungs => (
is => 'ro',
- isa => 'Lungs',
+ isa => 'Lungs',
handles => [ 'inhale', 'exhale' ],
);
@@ -3246,6 +3253,7 @@ has lungs => (
Array Reference
+ - 1-to-1 mapping
- Takes each method name and creates a simple delegation from the delegating class to the delegatee attribute
@@ -3368,7 +3376,7 @@ has history => (
use Moose;
has _favorite_numbers => (
traits => [ 'Array' ],
- is => 'ro',
+ is => 'bare',
isa => 'ArrayRef[Int]',
default => sub { [] },
init_arg => undef,
@@ -3406,7 +3414,7 @@ print "$_\n"
Bool - set, toggle, ...
Hash - get, set, ...
Array - already saw it
- Code - execute, that's it
+ Code - execute and execute_method
@@ -3471,7 +3479,7 @@ $person->account->deposit(100);
Traits and Metaclasses
- - Can add/alter/remove attribute parameter (from
has)
+ - Can add/alter/remove an attribute parameter (from
has)
- Can change behavior of created attribute
@@ -3529,15 +3537,12 @@ print Person->meta
Use weak_ref to avoid circular references
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
@@ -3547,12 +3552,20 @@ print Person->meta
Iterate til this passes all its tests
-
-
Part 7: Introspection
+
+
CYOA
+
+
+ If there is time, keep going ...
+
+
+
+ Otherwise, jump to slide 269 ...
+
-
Part 8: A Brief Tour of MooseX
+ Bonus: A Brief Tour of MooseX
@@ -3560,7 +3573,7 @@ Iterate til this passes all its tests
- Not comprehensive
- - 128 MooseX distributions on CPAN as of 09/24/2009
+ - 177 MooseX distributions on CPAN as of 09/21/2010
- Some of them are crap
@@ -3569,11 +3582,11 @@ Iterate til this passes all its tests
Already Mentioned Several
- - MooseX::NonMoose - best solution for subclassing non-Moose parents
- - MooseX::Declare - real Perl 5 OO
- - MooseX::FollowPBP and MooseX::SemiAffordanceAccessor
- - MooseX::Params::Validate and MooseX::Method::Signatures
- - MooseX::Types
+ MooseX::NonMoose - best solution for subclassing non-Moose parentsMooseX::Declare - real Perl 5 OOMooseX::FollowPBP and MooseX::SemiAffordanceAccessorMooseX::Params::Validate and MooseX::Method::SignaturesMooseX::Types
PPI, perltidy, etc. (yet?)
@@ -3607,7 +3621,7 @@ class Person {
MooseX::StrictConstructor
- - By default, unknown constructor arguments are ignore
+ - By default, unknown constructor arguments are ignored
- MX::StrictConstructor turns these into an error
@@ -3669,7 +3683,7 @@ use Moose;
has file =>
( is => 'ro', required => 1 );
has filters =>
- ( is => 'ro', isa => 'Str' );
+ ( is => 'ro', isa => 'ArrayRef[Str]' );
sub run { ... }
@@ -3685,7 +3699,7 @@ sub run { ... }
use App::CLI;
-App::CLI->new_with_options()->run();
+App::CLI->new_with_options()->run();
$ myapp-cli \
--file foo \
@@ -3745,12 +3759,21 @@ with HasCollection => { type => 'Int' };
Questions?
-
-
Part 9: Writing Moose Extensions
-
+
+
Moose-using Modules
-
-
The End
+
+ For further reading, a few modules which use Moose ...
+
+
+
@@ -3763,10 +3786,14 @@ with HasCollection => { type => 'Int' };
mailing list - moose@perl.org
Slides and exercises are in Moose's git repo:
- git://jules.scsys.co.uk/gitmo/moose-presentations
+
git://jules.scsys.co.uk/gitmo/moose-presentations
+
+
The End
+
+