NAME¶
Jifty::DBI::Record::Plugin - Record model mixins for Jifty::DBI
SYNOPSIS¶
# Define a mixin
package MyApp::FavoriteColor;
use base qw/ Jifty::DBI::Record::Plugin /;
# Define which methods you want to put in the host model
our @EXPORT = qw(
favorite_complementary_color
);
use Jifty::DBI::Schema;
use Jifty::DBI::Record schema {
column favorite_color =>
type is 'text',
label is 'Favorite Color',
valid_values are qw/ red green blue yellow /;
};
sub favorite_complementary_color {
my $self = shift; # whatever host object thing we've mixed with
my $color = $self->favorite_color;
return $color eq 'red' ? 'green'
: $color eq 'green' ? 'red'
: $color eq 'blue' ? 'orange'
: $color eq 'yellow' ? 'purple'
: undef;
}
# Use the mixin
package MyApp::Model::User;
use Jifty::DBI::Schema;
use Jifty::DBI::Record schema {
column name =>
type is 'text',
label is 'Name';
};
# Mixins
use MyApp::FavoriteColor;
sub name_and_color {
my $self = shift;
my $name = $self->name;
my $color = $self->favorite_color;
return "The favorite color of $name is $color.";
}
sub name_and_complementary_color {
my $self = shift;
my $name = $self->name;
my $color = $self->favorite_complementary_color;
return "The complement of $name's favorite color is $color.";
}
DESCRIPTION¶
By using this package you may provide models that are built from one or more
mixins. In fact, your whole table could be defined in the mixins without a
single column declared within the model class itself.
MODEL MIXINS¶
To build a mixin, just create a model that inherits from this package,
"Jifty::DBI::Record::Plugin". Then, add the schema definitions you
want inherited.
package MyApp::FasterSwallow;
use base qw/ Jifty::DBI::Record::Plugin /;
use Jifty::DBI::Schema;
use Jifty::DBI::Record schema {
column swallow_type =>
type is 'text',
valid are qw/ african european /,
default is 'african';
};
@EXPORT
A mixin may define an @EXPORT variable, which works exactly as advertised in
Exporter. That is, given the name of any methods or variable names in the
mixin, the host model will gain those methods.
our @EXPORT = qw( autocomplete_swallow_type );
sub autocomplete_swallow_type {
my $self = shift;
my $value = quotemeta(shift);
# You should probably find a better way than actually doing this...
my @values;
push @values, 'african' if 'african' =~ /$value/;
push @values, 'european' if 'european' =~ /$value/;
return @values;
}
That way if you have any custom methods you want to throw into the host model,
just define them in the mixin and add them to the @EXPORT variable.
register_triggers
Your mixin may also want to register triggers for the records to which it will
be added. You can do this by defining a method named
"register_triggers":
sub register_triggers {
my $self = shift;
$self->add_trigger(
name => 'before_create',
callback => \&before_create,
abortable => 1,
);
}
sub before_create {
# do something...
}
See Class::Trigger.
register_triggers_for_column
In addition to the general "register_triggers" method described above,
the mixin may also implement a "register_triggers_for_column"
method. This is called for each column in the table. This is primarily helpful
for registering the "after_set_*" and "before_set_*"
columns.
For example:
sub register_triggers_for_column {
my $self = shift;
my $column = shift;
return unless $column ne 'updated_on';
$self->add_trigger(
name => 'after_set_'.$column,
callback => \&touch_update_time,
abortable => 1,
);
}
sub touch_update_time {
my $self = shift;
$self->set_updated_on(DateTime->now);
}
This has the additional advantage of being callable when new columns are added
to a table while the application is running. This can happen when using
database-backed models in Jifty (which, as of this writing, has not been
released or made part of the development trunk of Jifty, but is part of the
virtual-models branch).
See Class::Trigger.
MODELS USING MIXINS¶
To use your model plugin, just use the mixins you want to get columns from. You
should still include a schema definition, even if it's empty:
package MyApp::Model::User;
use Jifty::DBI::Schema;
use MyApp::Record schema {
};
# Mixins
use MyApp::FavoriteColor;
use MyApp::FasterSwallow;
use Jifty::Plugin::User::Mixin::Model::User;
use Jifty::Plugin::Authentication::Password::Mixin::Model::User;
SEE ALSO¶
Jifty::DBI::Record, Class::Trigger
LICENSE¶
Jifty::DBI is Copyright 2005-2007 Best Practical Solutions, LLC. Jifty is
distributed under the same terms as Perl itself.