Module: Sequel::Plugins::Enum

Defined in:

lib/sequel/plugins/enum.rb

Overview

The enum plugin allows for easily adding methods to modify the value of a column. It allows treating the column itself as an enum, returning a symbol for the related enum value. It also allows for setting up dataset methods to easily find records having or not having each enum value.

After loading the plugin, you can call the enum method to define the methods. The enum method accepts a symbol for the underlying database column, and a hash with symbol keys for the enum values. For example, the following call:

Album.enum :status_id, good: 1, bad: 2

Will define the following instance methods:

Album#good!

Change status_id to 1 (does not save the receiver)

Album#bad!

Change status_id to 2 (does not save the receiver)

Album#good?

Return whether status_id is 1

Album#bad?

Return whether status_id is 2

It will override the following instance methods:

Album#status_id

Return +:good+/+:bad+ instead of +1+/+2+ (other values returned as-is)

Album#status_id=

Allow calling with +:good+/+:bad+ to set status_id to +1+/+2+ (other values, such as 'good'/'bad' set as-is)

If will define the following dataset methods:

Album.dataset.good

Return a dataset filtered to rows where status_id is 1

Album.dataset.not_good

Return a dataset filtered to rows where status_id is not 1

Album.dataset.bad

Return a dataset filtered to rows where status_id is 2

Album.dataset.not_bad

Return a dataset filtered to rows where status_id is not 2

When calling enum, you can also provide the following options:

:prefix :: Use a prefix for methods defined for each enum value. If true is provided at the value, use the column name as the prefix. For example, with prefix: 'status', the instance methods defined above would be status_good?, status_bad?, status_good!, and status_bad!, and the dataset methods defined would be status_good, status_not_good, status_bad, and status_not_bad. :suffix :: Use a suffix for methods defined for each enum value. If true is provided at the value, use the column name as the suffix. For example, with suffix: 'status', the instance methods defined above would be good_status?, bad_status?, good_status!, and bad_status!, and the dataset methods defined would be good_status, not_good_status, bad_status, and not_bad_status. :override_accessors :: Set to false to not override the column accessor methods. :dataset_methods :: Set to false to not define dataset methods.

Note that this does not use a true enum column in the database. If you are looking for enum support in the database, and your are using PostgreSQL, Sequel supports that via the pg_enum Database extension.

Usage:

# Make all model subclasses handle enums
Sequel::Model.plugin :enum

# Make the Album class handle enums
Album.plugin :enum

Defined Under Namespace

Modules: ClassMethods