NAME
Data::MultiValued::AttributeTrait - "base role" for traits of multi-valued Moose attributes
VERSION
version 0.0.1_3
DESCRIPTION
Don't use this role directly, use Data::MultiValued::AttributeTrait::Tags, Data::MultiValued::AttributeTrait::Ranges or Data::MultiValued::AttributeTrait::TagsAndRanges.
This role (together with Data::MultiValued::AttributeAccessors) defines all the basic plumbing to glue Data::MultiValued::Tags etc into Moose attributes.
Implementation details
The multi-value object is stored in the instance slot named by the "full_storage_slot" attribute attribute. before modifiers on getters load the appropriate value from the multi-value object into the regular instance slot, after modifiers on setters store the value from the regular instance slot into the multi-value object.
Attributes
This trait adds some attributes to the attribute declarations in your class. Example:
has stuff => (
is => 'rw',
isa => 'Int',
traits => ['MultiValued::Tags'],
predicate => 'has_stuff',
multi_accessor => 'stuff_tagged',
multi_predicate => 'has_stuff_tagged',
);ATTRIBUTES
full_storage_slot
The instance slot to use to store the Data::MultiValued::Tags or similar object. Defaults to "${name}__MULTIVALUED_STORAGE__", where $name is the attribute name.
multi_accessor
multi_reader
multi_writer
multi_predicate
multi_clearer
The names to use for the various additional accessors. See Class::MOP::Attribute for details. These default to "${name}_multi" where $name is the name of the corresponding non-multi accessor. So, for example,
has stuff => (
is => 'rw',
traits => ['MultiValued::Tags'],
);will create a stuff read / write accessor and a stuff_multi read / write tagged accessor.
METHODS
slots
Adds the "full_storage_slot" to the list of used slots.
set_full_storage
Stores a new instance of "multivalue_storage_class" into the "full_storage_slot" of the instance.
get_full_storage
Retrieves the value of the "full_storage_slot" of the instance.
full_storage
Returns an instance of "multivalue_storage_class", either by retrieving it from the instance, or by creating one (and setting it in the instance). Calls "get_full_storage" and "set_full_storage".
accessor_metaclass
Makes sure that all accessors for this attribute are created via the Data::MultiValued::AttributeAccessors method meta class.
install_accessors
After the regular Moose::Meta::Attribute method, installs the multi-value accessors.
Each installed normal accessor gets a multi-value version
You can add or rename the multi-value version by using the attributes described above
If you are passing explicit subrefs for your accessors, things won't work.
load_multi_value
Retrieves a value from the multi-value object, and stores it in the regular slot in the instance. If the value is not found, clears the slot.
This traps the Data::MultiValued::Exceptions::NotFound exception that may be thrown by the multi-value object, but re-throws any other exception.
raw_clear_value
Clears the instance slot. Does the same as "clear_value" in Moose::Meta::Attribute, but we need this method because the other one gets changed by this trait.
store_multi_value
Gets the value from the regular slot in the instance, and stores it into the multi-value object.
get_value
Before the normal method, calls "load_multi_value". Normally, no options will be passed to the multi-value object get method.
get_multi_value
Sets the options that "load_multi_value" will use, then calls "get_value".
The options are passed via an ugly localised package variable. There might be a better way.
set_initial_value
After the normal method, calls "store_multi_value".
set_value
set_multi_value
Just like "get_value" and "get_multi_value", but calling "store_multi_value" after the regular set_value
has_value
has_multi_value
Just like "get_value" and "get_multi_value".
clear_value
clear_multi_value
Call the clear method on the multi-value object.
get_multi_read_method
get_multi_write_method
Return the name of the reader or writer method, honoring "multi_reader", "multi_writer" and "multi_accessor".
REQUIREMENTS
These methods must be provided by any class consuming this role. See Data::MultiValued::AttributeTrait::Tags etc. for examples.
multivalue_storage_class
The class to use to create the multi-value objects.
opts_to_pass_set
Which options to pass from the multi-value accessors to the set method of the multi-value object.
opts_to_pass_get
Which options to pass from the multi-value accessors to the get method of the multi-value object.
Serialisation helpers
These are used through Data::MultiValued::UglySerializationHelperRole.
_rebless_slot
Blesses the value inside the "full_storage_slot" of the instance into "multivalue_storage_class", then calls _rebless_storage on it.
_as_hash
Returns the result of calling _as_hash on the value inside the "full_storage_slot" of the instance. Returns nothing if the slot does not have a value.
AUTHOR
Gianni Ceccarelli <dakkar@thenautilus.net>
COPYRIGHT AND LICENSE
This software is copyright (c) 2011 by Net-a-Porter.com.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.