<div class="slide">
<h1>Introduction to Moose</h1>
- <h2><a href="git://git.moose.perl.org/moose-presentations.git"><tt>git://git.moose.perl.org/moose-presentations.git</tt></a></h2>
+ <h2>Dave Rolsky</a>
+</div>
+
+<div class="slide">
+ <h1>Introduce Yourselves</h1>
+
+ <ul>
+ <li>Your name</li>
+ <li>What you do with Perl</li>
+ <li>Why you're here today (optional)</li>
+ </ul>
</div>
<div class="slide">
<ul>
<li>AKA advice</li>
<li>"<strong>Before</strong> foo(), do this first"</li>
- <li>"Do this <strong>after</strong> foo()</li>
+ <li>"Do this <strong>after</strong> foo()"</li>
<li>"Put this code <strong>around</strong> foo()"</li>
</ul>
</div>
);
# kaboom
-Person->new( weight => 'fat' );</code></pre>
+Person->new( weight => 'heavy' );</code></pre>
</div>
<div class="slide">
<span class="highlight">handles => { 'blog_host' => 'host' },</span>
);
-<span class="highlight">$person->blog_host;</span>
-# really calls $person->blog_uri->host</code></pre>
+<span class="highlight">$person->blog_host;</span>
+# really calls $person->blog_uri->host</code></pre>
</div>
<div class="slide">
<ul>
<li>Moose creates <code>new()</code> for you</li>
- <li>Provide an optional <code>BUIDARGS()</code> and <code>BUILD()</code></li>
+ <li>Provide an optional <code>BUILDARGS()</code> and <code>BUILD()</code></li>
</ul>
</div>
);</code></pre>
</div>
+<div class="slide">
+ <h1>More Why Moose?</h1>
+
+ <ul>
+ <li>Less code == fewer bugs</li>
+ <li>Moose is well-tested, test your own code, not Moose</li>
+ <li>Focus on <strong>what</strong>, not <strong>how</strong></li>
+ </ul>
+</div>
+
<div class="slide fake-slide0">
<h1>Part 1: Moose Classes</h1>
</div>
<h1>BUILDARGS</h1>
<ul>
- <li>Takes <code>@_</code>, returns a hash reference of attribute names/value</li>
+ <li>Takes <code>@_</code>, returns a hash reference of attribute name/value pairs</li>
<li>Accepts a hash or hashref; throws otherwise</li>
<li>Provide your own for other cases</li>
<li><strong>Always</strong> call <code>$class->SUPER::BUILDARGS(@_)</code> as a fallback!</li>
<pre><code>Person->new(@_)</code></pre>
- <ol>
+ <ol style="margin-top: 0">
<li>Calls <code>Person->BUILDARGS(@_)</code> to turn <code>@_</code> into a hashref</li>
<li>Blesses a reference</li>
<li>Populates attributes based on the hashref from #1</li>
- <li>Calls <code>$new_object->BUILDALL($constructor_args)</code>
+ <li>Calls <code>$new_object->BUILDALL($constructor_args)</code>
<br />... which calls all <code>BUILD</code> methods</li>
<li>Returns the object</li>
</ol>
<ul>
<li><code>extends</code> is sugar for declaring parent classes</li>
+ <li>Also ensures metaclass compatibility between parent and child</li>
+ <li>Do not <code>use base</code></li>
</ul>
<pre><code>package Employee;
<li>Mostly like <code>$self->SUPER::work(@_)</code></li>
<li><strong>But</strong> cannot change <code>@_</code>!</li>
<li>Binds the parent's method at compile time</li>
+ <li>Parent determined by checking <code>Child->meta()->superclasses()</code></li>
</ul>
</div>
use Moose;
# true
-Person->can('extends');</code></pre>
+Person->can('extends');</code></pre>
<ul>
<li>Not very hygienic</li>
...
-no Moose;
+<span class="highlight">no Moose;</span>
# false
-Person->can('extends');</code></pre>
+Person->can('extends');</code></pre>
+</div>
+
+<div class="slide">
+ <h1>Cleaning Up Moose Droppings</h1>
+
+ <pre><code>package Person;
+<span class="highlight">use namespace::autoclean;</span>
+use Moose;
+
+...
+
+# false
+Person->can('extends');</code></pre>
</div>
<div class="slide">
<h1>No Moose</h1>
<ul>
- <li><code>no Moose</code> at the end of a package is a best practice</li>
+ <li>Cleaning up is a best practice</li>
+ <li>Say <code>no Moose</code> at the end of a package</li>
<li>Or <code>use namespace::autoclean</code> at the top</li>
<li>Just do it</li>
</ul>
<h1>Immutability</h1>
<ul>
- <li><span style="font-family: URW Chancery L; font-size: 140%">Stevan's Incantation of Fleet-Footedness</span></li>
+ <li><span style="font-family: URW Chancery L; font-size: 120%">Stevan's Incantation of Fleet-Footedness</span></li>
</ul>
<pre><code>package Person;
use Moose;
-<span class="highlight">__PACKAGE__->meta->make_immutable;</span></code></pre>
+<span class="highlight">__PACKAGE__->meta->make_immutable;</span></code></pre>
</div>
<div class="slide">
<span class="delete">with 'Printable';</span>
-<span class="highlight">has has_been_printed => ( is => 'rw' );
+<span class="highlight">die '...' unless __PACKAGE__->can('as_string');
+
+has has_been_printed => ( is => 'rw' );
sub print {
my $self = shift;
# or ...
-Person->meta->does('Printable')</code></pre>
+Person->meta->does_role('Printable')</code></pre>
</div>
sub break {
my $self = shift;
- $self->break_it_down;
+ $self->break_it_down;
if ( rand(1) < 0.5 ) {
- $self->break_bone;
+ $self->break_bone;
}
}</code></pre>
</div>
sub is_equal {
my $self = shift;
- return $self->compare(@_) == 0;
+ return $self->compare(@_) == 0;
}</code></pre>
</div>
# Satisfies the Comparable role
sub compare { ... }
-Integer->does('TestsEquality'); # true
-Integer->does('Comparable'); # also true!</code></pre>
+Integer->does('TestsEquality'); # true
+Integer->does('Comparable'); # also true!</code></pre>
</div>
<div class="slide">
<pre><code>use Moose::Util qw( apply_all_roles );
-my $fragile_person = Person->new( ... );
+my $fragile_person = Person->new( ... );
apply_all_roles( $fragile_person,
'IsFragile' );</code></pre>
<span class="current incremental">required => 1,</span>
);
-<span class="incremental">Person->new( first_name => undef ); # ok
-Person->new(); # kaboom</span></code></pre>
+<span class="incremental">Person->new( first_name => undef ); # ok
+Person->new(); # kaboom</span></code></pre>
</div>
<div class="slide">
use Moose;
my $highlander_bank =
- Bank->new( name => 'Spire FCU' );
+ Bank->new(
+ name => 'Clan MacLeod Trust' );
has bank => (
is => 'rw',
<h1>Builder</h1>
<ul>
- <li>A method <em>name</em> which returns the default</li>
+ <li>A method <em>name</em></li>
+ <li>When called, this method returns the default value</li>
</ul>
</div>
use Moose;
has shoe_size => (
- is => 'ro',
+ is => 'ro',
+ required => 'ro',
);</code></pre>
</div>
<span class="highlight">init_arg => 'foot_size',</span>
);
-Person->new( <span class="wrong">shoe_size => 13</span> );
+Person->new( <span class="wrong">shoe_size => 13</span> );
my $person =
- Person->new( <span class="right">foot_size => 13</span> );
-print $person->shoe_size;</code></pre>
+ Person->new( <span class="right">foot_size => 13</span> );
+print $person->shoe_size;</code></pre>
</div>
<div class="slide">
<span class="highlight">init_arg => undef,</span>
);
-Person->new( <span class="wrong">shoes => Shoes->new</span> );</code></pre>
+Person->new( <span class="wrong">shoes => Shoes->new</span> );</code></pre>
</div>
<div class="slide">
<li>Attributes can have a <code>default</code> or <code>builder</code></li>
<li>Attributes with a default or builder can be <code>lazy</code></li>
<li>Attributes can have a <code>clearer</code> and/or <code>predicate</code></li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Basic Attributes Summary</h1>
+
+ <ul>
<li>An attribute's constructor name can be changed with <code>init_arg</code></li>
<li>A subclass can alter its parents' attributes</li>
<li>Attribute accessor names can be changed</li>
<ul>
<li>Apply to an existing method</li>
- <li>... from a parent class, the current class, or a role</li>
+ <li>... that comes from a parent class, the current class, or a role</li>
<li>Roles can provide modifiers that are applied at composition time</li>
</ul>
</div>
<div class="slide">
- <h1>What is a Method Modifier</h1>
+ <h1>What Are Method Modifiers For?</h1>
<ul>
<li>"Inject" behavior</li>
<li>Add behavior to generated methods (accessors, delegations)</li>
- <li>Provide roles which modify existing behavior</li>
+ <li>Added from a role, can modify existing behavior</li>
</ul>
</div>
$self->$orig(
$self->_munge_insert(@_) );
- $new_user->_assign_uri;
+ $new_user->_assign_uri;
return $new_user;
};</code></pre>
</div>
<h1>Modifier Order</h1>
<ul>
- <li>Before runs order from last to first</li>
+ <li>Before runs in order from last to first</li>
<li>After runs in order from first to last</li>
<li>Around runs in order from last to first</li>
</ul>
<ul>
<li>Inverted <code>super</code></li>
<li>From least- to most-specific</li>
+ <li>Like Mason's autohandler feature</li>
<li>Grandparent to parent to child</li>
<li>Not allowed in roles</li>
</ul>
Undef
Defined
Value
- Num
- Int
- Str
- ClassName
- RoleName
+ Str
+ Num
+ Int
+ ClassName
</pre>
</div>
<pre>
(Item)
(Defined)
+ (Value)
Ref
ScalarRef
ArrayRef[`a]
CodeRef
RegexpRef
GlobRef
- FileHandle
+ FileHandle
Object
</pre>
</div>
<ul>
<li><code>Value</code> is true when <code>! ref $thing</code></li>
<li><code>Value</code> and <code>Str</code> are effectively the same, but <code>Str</code> is more expressive</li>
+ <li><code>Num</code> is true when a <code>$scalar</code> looks like a number</li>
<li>An overloaded object which numifies does not pass the <code>Num</code> constraint!</li>
<li>Perl 5's overloading is hopelessly broken</li>
</ul>
<h1>Subtype Shortcuts - <code>class_type</code></h1>
<pre><code>use Moose::Util::TypeConstraints;
-class_type 'DateTime';
+class_type 'DateTime';</code></pre>
+
+<hr />
-subtype 'DateTime',
+<pre><code>subtype 'DateTime',
as 'Object',
where { $_->isa('DateTime') },
message { ... };</code></pre>
<h1>Subtype Shortcuts - <code>role_type</code></h1>
<pre><code>use Moose::Util::TypeConstraints;
-role_type 'Printable';
+role_type 'Printable';</coe></pre>
-subtype 'Printable',
+<hr />
+
+<pre><code>subtype 'Printable',
as 'Object',
where
{ Moose::Util::does_role(
<h1>Subtype Shortcuts - <code>duck_type</code></h1>
<pre><code>use Moose::Util::TypeConstraints;
-duck_type Car => qw( run break_down );
+duck_type Car => qw( run break_down );</code></pre>
+
+<hr />
-subtype 'Car',
+<pre><code>subtype 'Car',
as 'Object',
where { all { $_->can($_) }
qw( run break_down ) },
<h1>Subtype Shortcuts - <code>enum</code></h1>
<pre><code>use Moose::Util::TypeConstraints;
-enum Color => qw( red blue green ) );
+enum Color => qw( red blue green ) );</code></pre>
+
+<hr />
-my %ok = map { $_ => 1 }
+<pre><code>my %ok = map { $_ => 1 }
qw( red blue green );
subtype 'Color'
via { [ $_ ] };</code></pre>
<ul>
- <li>Coerce instead of a union like <code style="white-space: nowrap">Int | ArrayRef[Int]</code></li>
+ <li>Instead of union - <code style="white-space: nowrap">Int | ArrayRef[Int]</code></li>
</ul>
</div>
\@_,
tasks =>
{ isa => 'ArrayRef[Task]',
- coerce =>1 },
+ coerce => 1 },
can_rest =>
{ isa => 'Bool',
default => 0 },
<ul>
<li>Type names are exported functions, catches typos early</li>
<li>Types must be pre-declared</li>
- <li>Types are stored with namespaces internally, but externally are short</li>
+ <li>Types are stored with namespaces internally, but you use short names</li>
<li>Import existing Moose types as functions from <code>MooseX::Types::Moose</code></li>
<li>Still need string names for things like <code>ArrayRef['Email::Address']</code></li>
</ul>
<li><span class="right">Catches typos at compile time</span></li>
<li><span class="right">Automatic namespacing</span></li>
<li><span class="wrong">One more thing to install and learn</span></li>
- <li><span class="wrong">Every name gets types twice (declared and then defined)</span></li>
+ <li><span class="wrong">Every name is typed twice (declared and then defined)</span></li>
<li><span class="wrong">Still stuck with strings when referring to class or role names</span></li>
<li><span class="wrong">Coercion gotcha from earlier still applies to types exported from <code>MooseX::Types::Moose</code></span></li>
</ul>
<pre><code>after salary_level => {
my $self = shift;
- return unless @_;
+ <span class="highlight">return unless @_;</span>
$self->clear_salary;
};</code></pre>
</div>
<pre><code>has salary_level => (
is => 'rw',
- trigger => sub { $_[0]->clear_salary },
+ trigger =>
+ sub { $_[0]->clear_salary },
);</code></pre>
</div>
<div class="slide">
+ <h1>Trigger Arguments</h1>
+
+ <ul>
+ <li><code>$self</code></li>
+ <li><code>$new_value</code></li>
+ <li><code>$old_value</code> - if one exists</li>
+ </ul>
+</div>
+
+<div class="slide">
<h1>Delegation</h1>
<ul>
<h1>Array Reference</h1>
<ul>
+ <li>1-to-1 mapping</li>
<li>Takes each method name and creates a simple delegation from the delegating class to the delegatee attribute</li>
</ul>
</div>
<ul>
<li>Delegate to <em>unblessed</em> Perl types</li>
<li>Scalar, array or hash ref, etc</li>
+ <li>Treat Perl types as objects</li>
+ <li>Still uses <code>handles</code></li>
+ <li>Pretend that native Perl types have methods</li>
</ul>
</div>
<div class="slide">
- <h1>Native Delegation - Array</h1>
+ <h1>Native Delegation - Array(Ref)</h1>
+
+ <ul>
+ <li>Methods include:
+ <ul>
+ <li><code>push</code></li>
+ <li><code>shift</code></li>
+ <li><code>elements</code> - returns all elements</li>
+ <li><code>count</code></li>
+ <li><code>is_empty</code></li>
+ <li>quite a few more</li>
+ </ul>
+ </li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Native Delegation - Array(Ref)</h1>
<pre><code>package Person;
use Moose;
</div>
<div class="slide">
- <h1>Native Delegation - Counter</h1>
+ <h1>Native Delegation - Array(Ref)</h1>
+
+ <pre><code>my $person = Person->new();
+
+$person->add_favorite_number(7);
+$person->add_favorite_number(42);
+
+print "$_\n"
+ for $person->favorite_numbers;
+
+# 7
+# 42</code></pre>
+</div>
+
+<div class="slide">
+ <h1>Native Delegation</h1>
+
+ <ul>
+ <li>Native types are ...
+ <ul>
+ <li>Number - <code>add</code>, <code>mul</code>, ...</li>
+ <li>String - <code>append</code>, <code>chop</code>, ...</li>
+ <li>Counter - <code>inc</code>, <code>dec</code>, ...</li>
+ <li>Bool - <code>set</code>, <code>toggle</code>, ...</li>
+ <li>Hash - <code>get</code>, <code>set</code>, ...</li>
+ <li>Array - already saw it</li>
+ <li>Code - <code>execute</code> and <code>execute_method</code></li>
+ </ul>
+ </li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Curried Delegation</h1>
+
+ <ul>
+ <li>A delegation with some preset arguments</li>
+ <li>Works with object or Native delegation</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Curried Delegation</h1>
- <pre><code>package Stack;
+ <pre><code>package Person;
use Moose;
-has depth => (
- traits => [ 'Counter' ],
- is => 'ro',
- isa => 'Int',
- default => 0,
- init_arg => undef,
- <span class="highlight">handles =>
- { _inc_depth => 'inc',
- _dec_depth => 'dec',
- },</span>
+has account => (
+ is => 'ro',
+ isa => 'BankAccount',
+ handles => {
+ receive_100 =>
+ <span class="highlight">[ 'deposit', 100 ]</span>
+ give_100 =>
+ <span class="highlight">[ 'withdraw', 100 ]</span>
+ },
);</code></pre>
</div>
+<div class="slide">
+ <h1>Curried Delegation</h1>
+
+ <pre><code>$person->receive_100;
+# really is
+$person->account->deposit(100);</code></pre>
+</div>
<div class="slide">
<h1>Traits and Metaclasses</h1>
<h1>Traits and Metaclasses</h1>
<ul>
- <li>Can add/alter/remove attribute parameter (from <code>has</code>)</li>
+ <li>Can add/alter/remove an attribute parameter (from <code>has</code>)</li>
<li>Can change behavior of created attribute</li>
</ul>
</div>
</div>
<div class="slide fake-slide0">
- <h1>Part 8: A Tour of MooseX</h1>
+ <h1>Part 8: A Brief Tour of MooseX</h1>
+</div>
+
+<div class="slide">
+ <h1>Notable MX Modules on CPAN</h1>
+
+ <ul>
+ <li><strong>Not comprehensive</strong></li>
+ <li>152 MooseX distributions on CPAN as of 02/02/2010</li>
+ <li>Some of them are crap</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>Already Mentioned Several</h1>
+
+ <ul>
+ <li><code>MooseX::NonMoose</code> - best solution for subclassing non-Moose parents</li>
+ <li><code>MooseX::Declare</code> - <em>real</em> Perl 5 OO</li>
+ <li><code>MooseX::FollowPBP</code> and <code>MooseX::SemiAffordanceAccessor</code></li>
+ <li><code>MooseX::Params::Validate</code> and <code>MooseX::Method::Signatures</code></li>
+ <li><code>MooseX::Types</code></li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>MooseX::Declare</h1>
+
+<pre><code>use MooseX::Declare;
+use 5.10.0; # for say
+
+class Person {
+ has greeting =>
+ ( is => 'ro', isa => 'Str' );
+
+ method speak {
+ say $self->greeting;
+ }
+}</code></pre>
+</div>
+
+<div class="slide">
+ <h1>MooseX::Declare</h1>
+
+ <ul>
+ <li>Still experimental-ish, but seeing more and more use</li>
+ <li><strong>Not</strong> a source filter!</li>
+ <li>Hooks into the Perl parser rather than filtering all your code</li>
+ <li>But not supported by <code>PPI</code>, <code>perltidy</code>, etc.</li> (yet?)
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>MooseX::StrictConstructor</h1>
+
+ <ul>
+ <li>By default, unknown constructor arguments are ignored</li>
+ <li>MX::StrictConstructor turns these into an error</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>MooseX::StrictConstructor</h1>
+
+ <pre><code>package Person;
+
+use Moose;
+<span class="highlight">use MooseX::StrictConstructor;</span>
+
+has name => ( is => 'ro' );
+
+Person->new
+ ( na<span class="wrong">n</span>e => 'Ringo Shiina' ); # kaboom</code></pre>
+</div>
+
+<div class="slide">
+ <h1>MooseX::Traits</h1>
+
+ <ul>
+ <li>Combines object construction and role application</li>
+ <li>Makes it easy to create one-off customized objects</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>MooseX::Traits</h1>
+
+ <pre><code>package MyApp::Thingy;
+use Moose;
+
+<span class="highlight">with 'MooseX::Traits';</span>
+
+my $thing =
+ MyApp::Thingy-><span class="highlight">new_with_traits</span>
+ ( <span class="highlight">traits => [ 'Foo', 'Bar' ],</span>
+ size => 42 );</code></pre>
+</div>
+
+<div class="slide">
+ <h1>MooseX::Getopt</h1>
+
+ <ul>
+ <li>Makes command-line interface programs easy!</li>
+ <li>Construct an object from CLI arguments</li>
+ </ul>
</div>
+<div class="slide">
+ <h1>MooseX::Getopt</h1>
+
+ <pre><code>package App::CLI;
+use Moose;
+
+<span class="highlight">with 'MooseX::Getopt';</span>
+
+has file =>
+ ( is => 'ro', required => 1 );
+has filters =>
+ ( is => 'ro', isa => 'ArrayRef[Str]' );
+
+sub run { ... }</code></pre>
+</div>
+
+<div class="slide">
+ <h1>MooseX::Getopt</h1>
+
+ <ul>
+ <li>Then call it like this:</li>
+ </ul>
+
+<pre><code>#!/usr/bin/perl
+
+use App::CLI;
+
+<span class="highlight">App::CLI->new_with_options()</span>->run();</code></pre>
+
+<pre>$ myapp-cli \
+ --file foo \
+ --filters compress \
+ --filters sanitize</pre>
+</div>
+
+<div class="slide">
+ <h1>MooseX::Clone</h1>
+
+ <pre><code>package Person;
+
+use Moose;
+<span class="highlight">with 'MooseX::Clone';</span>
+
+my $person = Person->new;
+my $clone = <span class="highlight">$person->clone;</span></code></pre>
+</div>
+
+<div class="slide">
+ <h1>MooseX::NonMoose</h1>
+
+ <ul>
+ <li>Highly recommended for subclassing non-Moose parents</li>
+ <li>Gets all the little annoying details right</li>
+ </ul>
+</div>
+
+<div class="slide">
+ <h1>MooseX::Role::Parameterized</h1>
+
+ <pre><code>package HasCollection;
+<span class="current incremental">use MooseX::Role::Parameterized;</span>
+<span class="incremental">parameter type => ( isa => 'Str',
+ default => 'Item' );</span>
+<span class="incremental">role {
+ my $p = shift;
+
+ my $type =
+ 'ArrayRef[' . $p->type() . ']';
+ has collection =>
+ ( is => 'ro',
+ isa => $type );
+};</span></code></pre>
+</div>
+
+<div class="slide">
+ <h1>MooseX::Role::Parameterized</h1>
+
+ <pre><code>package Person;
+
+use Moose;
+with HasCollection => { type => 'Int' };</code></pre>
+</div>
+
+<div class="slide">
+ <h1>Questions?</h1>
+</div>
+
<div class="slide fake-slide0">
<h1>Part 9: Writing Moose Extensions</h1>
</div>
<li>mailing list - <a href="mailto:moose@perl.org">moose@perl.org</a></li>
<li>Slides and exercises are in Moose's git repo:
<br />
- <span style="white-space: nowrap">git://jules.scsys.co.uk/gitmo/moose-presentations</span></li>
+ <span style="font-size:80%; white-space: nowrap">git://jules.scsys.co.uk/gitmo/moose-presentations</span></li>
</ul>
</div>