Configuring simple_enum

Different options to as_enum can be provided to change the behavior, basic usage is like:

as_enum :enum_name, # Name of enum, the column is {{enum_name}}_cd
        Array/Hash, # Enum values as either Hash or Array
        Hash        # (Optional) Hash with options for enum

Options for as_enum

column: String

Set the name of the column to store the value in, defaults to {{enum_name}}_cd.

Note It is not allowed to use the same column name as the enum name, this will throw an exception.

# Store value in sex, instead of gender_cd
as_enum :gender, %w{male female}, column: 'sex'

# Example:
user = User.new(sex: 1)
user.gender # => 'male'
user.sex    # => 1

dirty: true

When set to true generates {{enum_name}}_was and {{enum_name}}_changed? methods for the enum, which delegate to the internal column.

Defaults to false.

# Enable dirty attributes
as_enum :service, %w{twitter facebook google}, dirty: true

# Example:
user = User.new(service: :twitter)
user.service = :google
user.service_was      # => :twitter
user.service_changed? # => true

prefix: true/String

Define a prefix, which is prepended to shortcut methods (e.g. {{symbol}}! and {{symbol}}?), if it's set to true the enum name is used as prefix, else the custom supplied String.

Defaults to nil, i.e. no prefix.

# Use custom prefix
as_enum :gender, %w{male female}, prefix: 'sex'

# Use enum name as prefix
as_enum :service, %w{twitter facebook google}, prefix: true

# Example:
user = User.new(service: :twitter, gender: :female)

user.sex_female?       # => true

user.service_twitter?  # => true
user.service_google!   # => true
user.service           # => :google

Enum values

The enum values can either be provided as Array or a Hash. When using a Hash, the Hash key is the enum symbol and the Hash value is stored in the column. Hashes are favored over Arrays, because when using Arrays the 0-based index of the value is stored in the column.

Disclaimer When using Arrays ensure to never reorder it or remove items, because this would change the index.

# **Hash** with values, uses hash key as enum symbol and the value is
# stored in service_cd.
#
# So when setting the value to e.g. `:facebook`, `1` is stored
# in service_cd.
as_enum :service, { twitter: 0, facebook: 1, google: 2 }

# **Array** of values, stores index of values in service_cd.
#
# So when setting the value to e.g. `:facebook`, `1` is stored
# in service_cd.
as_enum :service, [:twitter, :facebook, :google]

# **Array** of values, but storing strings in service_cd, by setting the
# `:strings` options to true.
#
# So when setting the value to e.g. `:facebook`, `facebook` is stored
# in service_cd column.
as_enum :service, [:twitter, :facebook, :google], strings: true