Ash Integration

Plurality ships optional building blocks for Ash applications: changes, validations, and calculations for noun inflection. These modules compile away to nothing if Ash isn't loaded — no extra dependencies required.

Changes

Auto-inflect an attribute from another attribute on create or update.

Pluralize

defmodule MyApp.Resource do
  use Ash.Resource

  attributes do
    attribute :name, :string
    attribute :table_name, :string
  end

  actions do
    create :create do
      change {Plurality.Ash.Changes.Pluralize, attribute: :table_name, from: :name}
    end
  end
end

When :name is "user", :table_name is set to "users".

Options:

• :attribute (atom, required) — the attribute to write the inflected form to
• :from (atom, required) — the source attribute to read from

If the source attribute is nil, the changeset is returned unchanged.

Singularize

change {Plurality.Ash.Changes.Singularize, attribute: :resource_name, from: :label}

Same options as Pluralize. Writes the singular form of the source attribute.

Validations

Ensure an attribute value is in the expected inflected form.

PluralForm

validate {Plurality.Ash.Validations.PluralForm, attribute: :table_name}

Fails validation if the attribute value is not in plural form. nil values pass (use allow_nil? false on the attribute if presence is required). Uncountable words like "software" pass since they are valid in plural context.

Options:

• :attribute (atom, required) — the attribute to validate

SingularForm

validate {Plurality.Ash.Validations.SingularForm, attribute: :resource_name}

Same as PluralForm but validates the value is in singular form.

Calculations

Derive plural or singular forms without storing them as attributes.

Pluralize

calculations do
  calculate :name_plural, :string, {Plurality.Ash.Calculations.Pluralize, attribute: :name}
end

Returns the plural form of the source attribute. Returns nil if the source is nil.

Options:

• :attribute (atom, required) — the source attribute to inflect

Singularize

calculations do
  calculate :name_singular, :string, {Plurality.Ash.Calculations.Singularize, attribute: :name}
end

Full example

defmodule MyApp.Schema do
  use Ash.Resource,
    domain: MyApp.Admin,
    data_layer: AshPostgres.DataLayer

  attributes do
    uuid_primary_key :id
    attribute :name, :string, allow_nil?: false
    attribute :table_name, :string
    attribute :resource_name, :string
  end

  actions do
    create :create do
      accept [:name]
      change {Plurality.Ash.Changes.Pluralize, attribute: :table_name, from: :name}
      change {Plurality.Ash.Changes.Singularize, attribute: :resource_name, from: :name}
    end

    update :update do
      accept [:name]
      validate {Plurality.Ash.Validations.PluralForm, attribute: :table_name}
      validate {Plurality.Ash.Validations.SingularForm, attribute: :resource_name}
    end
  end

  calculations do
    calculate :display_plural, :string, {Plurality.Ash.Calculations.Pluralize, attribute: :name}
    calculate :display_singular, :string, {Plurality.Ash.Calculations.Singularize, attribute: :name}
  end
end

Conditional compilation

All Ash integration modules are wrapped in if Code.ensure_loaded?/1 checks. If Ash is not in your dependency tree, these modules don't exist and have zero impact on compilation or runtime. You don't need to do anything to enable or disable them — it's automatic.