package CatalystX::DynamicComponent;
use MooseX::Role::Parameterized;
+use MooseX::Types::Moose qw/Str CodeRef HashRef ArrayRef/;
+use Catalyst::Utils;
+use Moose::Util::TypeConstraints;
+use List::MoreUtils qw/uniq/;
use namespace::autoclean;
+enum __PACKAGE__ . '::ResolveStrategy' => qw/
+ merge
+ replace
+/;
+
+our $VERSION = 0.000001;
+
parameter 'name' => (
- isa => 'Str',
+ isa => Str,
required => 1,
);
parameter 'pre_immutable_hook' => (
- isa => 'Str',
+ isa => CodeRef|Str,
predicate => 'has_pre_immutable_hook',
);
-parameter 'COMPONENT' => (
- isa => 'CodeRef',
- predicate => 'has_custom_component_method',
+my %parameters = (
+ methods => {
+ isa =>HashRef,
+ default => sub { {} },
+ resolve_strategy => 'merge',
+ },
+ roles => {
+ isa => ArrayRef,
+ default => sub { [] },
+ resolve_strategy => 'merge',
+ },
+ superclasses => {
+ isa => ArrayRef,
+ default => sub { [] },
+ resolve_strategy => 'replace',
+ },
+);
+
+# Shameless metaprogramming.
+foreach my $name (keys %parameters) {
+ my $resolve_strategy = delete $parameters{$name}->{resolve_strategy};
+
+ parameter $name, %{ $parameters{$name} };
+
+ parameter $name . '_resolve_strategy' => (
+ isa => __PACKAGE__ . '::ResolveStrategy',
+ default => $resolve_strategy,
+ );
+}
+
+# Code refs to implement the strategy types
+my %strategies = ( # Right hand precedence where appropriate
+ replace => sub { $_[1] ? $_[1] : $_[0]; },
+ merge => sub {
+ if (ref($_[0]) eq 'ARRAY') {
+ [ uniq( @{ $_[0] }, @{ $_[1] } ) ];
+ }
+ else {
+ Catalyst::Utils::merge_hashes(shift, shift);
+ }
+ },
);
+# Wrap all the crazy up in a method to generically merge configs.
+my $get_resolved_config = sub {
+ my ($name, $p, $config) = @_;
+ my $get_strategy_method_name = $name . '_resolve_strategy';
+ my $strategy = $strategies{$p->$get_strategy_method_name()};
+ $strategy->($p->$name, $config->{$name})
+ || $parameters{$name}->{default}->();
+};
+
role {
my $p = shift;
my $name = $p->name;
my $pre_immutable_hook = $p->pre_immutable_hook;
+
method $name => sub {
- my ($app, $name, $config, $methods) = @_;
+ my ($app, $name, $config) = @_;
+
+ $config ||= {};
my $appclass = blessed($app) || $app;
my $type = $name;
$type =~ s/::.*$//;
my $meta = Moose->init_meta( for_class => $name );
- $meta->superclasses('Catalyst::' . $type);
+
+ my @superclasses = @{ $get_resolved_config->('superclasses', $p, $config) };
+ push(@superclasses, 'Catalyst::' . $type) unless @superclasses;
+ $meta->superclasses(@superclasses);
- if ($p->has_custom_component_method) {
- $meta->add_method(COMPONENT => $p->COMPONENT);
+ if (my @roles = @{ $get_resolved_config->('roles', $p, $config) }) {
+ Moose::Util::apply_all_roles( $name, @roles);
}
-
- $app->$pre_immutable_hook($meta) if $p->has_pre_immutable_hook;
-
- $methods ||= {};
+
+ my $methods = $get_resolved_config->('methods', $p, $config);
foreach my $name (keys %$methods) {
$meta->add_method($name => $methods->{$name});
}
+
+ if ($p->has_pre_immutable_hook) {
+ if (!ref($pre_immutable_hook)) {
+ $app->$pre_immutable_hook($meta, $config);
+ }
+ else {
+ $pre_immutable_hook->($meta, $config);
+ }
+ }
+
$meta->make_immutable;
my $instance = $app->setup_component($name);
1;
+__END__
+
+=head1 NAME
+
+CatalystX::DynamicComponent - Parameterised Moose role providing functionality to build Catalyst components at runtime.
+
+=head1 SYNOPSIS
+
+ package My::DynamicComponentType;
+ use Moose::Role;
+ use namespace::autoclean;
+
+ with 'CatalystX::DynamicComponent' => {
+ name => '_setup_one_of_my_components', # Name of injected method
+ };
+
+ after setup_components => sub { shift->_setup_all_my_components(@_); };
+
+ sub _setup_all_my_components {
+ my ($self, $c) = @_;
+ my $app = ref($self) || $self;
+ foreach my $component_name ('Controller::Foo') {
+ my %component_config = %{ $c->config->{$component_name} };
+ # Shallow copy so we avoid stuffing methods back in the config, as that's lame!
+ $component_config{methods} = {
+ some_method => sub { 'foo' },
+ };
+
+ # Calling this method creates a component, and registers it in your application
+ # This component will subclass 'MyApp::ControllerBase', do 'MyApp::ControllerRole'
+ # and have a method called 'some_method' which will return the value 'foo'..
+ $self->_setup_one_of_my_components($app . '::' . $component_name, \%component_config);
+ }
+ }
+
+ package MyApp;
+ use Moose;
+ use namespace::autoclean;
+ use Catalyst qw/
+ +My::DynameComponentType
+ /;
+ __PACKAGE__->config(
+ name => 'MyApp',
+ 'Controller::Foo' => {
+ superclasses => [qw/MyApp::ControllerBase/],
+ roles => [qw/MyApp::ControllerRole/],
+ },
+ );
+ __PACKAGE__->setup;
+
+=head1 DESCRIPTION
+
+CatalystX::DynamicComponent aims to provide a flexible and reuseable method of building L<Roles|Moose::Role>
+which can be added to L<Catalyst> applications, which generate components dynamically at application
+startup using the L<Moose> meta model.
+
+Thi is implemented as a parametrised role which curries a
+component builder method into your current package at application time.
+
+Authors of specific dynamic component builders are expected implement an application class
+roles which composes this role, and their own advice after the C<< setup_compontents >>
+method, which will call the component generation method provided by using this role once
+for each component you wish to create.
+
+=head1 PARAMETERS
+
+=head2 name
+
+B<Required> - The name of the component generator method to curry.
+
+=head2 methods
+
+Optional, a hash reference with keys being method names, and values being a L<Class::MOP::Method>,
+or a plain code ref of a method to apply to
+the dynamically generated package before making it immutable.
+
+=head2 roles
+
+Optional, an array reference of roles to apply to the generated component
+
+=head2 superclasses
+
+Optional, an array reference of superclasses to give the generated component.
+
+If this is not defined, and not passed in as an argument to the generation method,
+then Catalyst::(Model|View|Controller) will used as the base class (as appropriate given
+the requested namespace of the generated class, otherwise Catalyst::Component will be used.
+
+FIXME - Need tests for this.
+
+=head2 pre_immutable_hook
+
+Optional, either a coderef, which will be called with the component $meta and the merged $config,
+or a string name of a method to call on the application class, with the same parameters.
+
+This hook is called after a component has been generated and methods added, but before it is made
+immutable, constructed, and added to your component registry.
+
+=head1 CURRIED COMPONENT GENERATOR
+
+=head2 ARGUMENTS
+
+=over
+
+=item *
+
+$component_name (E.g. C<< MyApp::Controller::Foo >>)
+
+=item *
+
+$config (E.g. C<< $c->config->{$component_name} >>)
+
+=back
+
+=head3 config
+
+It is possible to set each of the roles, methods and superclasses parameters for each generated package
+individually by defining those keys in the C< $config > parameter to your curried component generation method.
+
+By default, roles and methods supplied from the curried role, and those passed as config will be merged.
+
+Superclasses, no the other hand, will replace those from the curried configuration if passed as options.
+This is to discourage accidental use of multiple inheritence, if you need this feature enabled, you should
+probably be using Roles instead!
+
+It is possible to change the default behavior of each parameter by passing a
+C< $param_name.'_resolve_strategy' > parameter when currying a class generator, with values of either
+C<merge> or C<replace>.
+
+Example:
+
+ package My::ComponentGenerator;
+ use Moose;
+
+ with 'CatalystX::DynamicComponent' => {
+ name => 'generate_magic_component',
+ roles => ['My::Role'],
+ roles_resolve_strategy => 'replace',
+ };
+
+ package MyApp;
+ use Moose;
+ use Catalyst qw/
+ My::ComponentGenerator
+ /;
+ extends 'Catalyst';
+ after 'setup_components' => sub {
+ my ($app) = @_;
+ # Component generated has no roles
+ $app->generate_magic_component('MyApp::Controller::Foo', { roles => [] });
+ # Component generated does My::Role
+ $app->generate_magic_component('MyApp::Controller::Foo', {} );
+ };
+ __PACKAGE__->setup;
+
+=head2 OPERATION
+
+FIXME
+
+=head1 TODO
+
+=over
+
+=item *
+
+Test pre_immutable hook in tests
+
+=item *
+
+More tests fixme?
+
+=item *
+
+Unlame needing to pass fully qualified component name in, that's retarded...
+
+Remember to fix the docs and clients too ;)
+
+=back
+
+=head1 LINKS
+
+L<Catalyst>, L<MooseX::MethodAttributes>, L<CatalystX::ModelsFromConfig>.
+
+=head1 BUGS
+
+Probably plenty, test suite certainly isn't comprehensive.. Patches welcome.
+
+=head1 AUTHOR
+
+Tomas Doran (t0m) <bobtfish@bobtfish.net>
+
+=head1 LICENSE
+
+This code is copyright (c) 2009 Tomas Doran. This code is licensed on the same terms as perl
+itself.
+
+=cut
+