@appling/codegen-ash

Appling code generation extension for Ash on Elixir. It turns an Appling model into a draft Ash project with AshPostgres, using Ash's own generators through Igniter.

{
  "generate": [
    { "extension": "@appling/codegen-ash", "out": "build/shop" }
  ]
}

The project is created next to the output folder with mix igniter.new <name>, so the project name (the name option, or by default the output folder's name) must be the output folder's name.

Requires Elixir 1.17 or later and the igniter_new archive (mix archive.install hex igniter_new).

What it generates

| Model | Ash | |---|---| | project | mix igniter.new <name> --install ash,ash_postgres | | module | mix ash.gen.domain <App>.<Module> | | enum | mix ash.gen.enum | | value | an embedded resource | | entity | mix ash.gen.resource with a UUID primary key, default actions, timestamps and the Postgres data layer | | field types | :string, :integer, :decimal, :boolean, :date, :utc_datetime_usec, :duration, :uuid; enums and value types by module; lists as arrays | | entity field | a belongs_to relationship, added after all resources exist | | unique, ?, default | an identity, allow_nil?, default | | derived field | a calculation with an Ash expression | | invariant | a validation built from compare, attribute_equals, attribute_in, present, all, any and negate | | action on an entity | an update action: arguments for inputs, validations for preconditions and guards, set_attribute or atomic_update changes, and transition_state | | machine | an AshStateMachine section; transitions on an event get an update action named after the event | | scheduled job | an AshOban trigger with where and scheduler_cron; now - duration("720h") becomes ago(720, :hour) | | query | a read action with filter, sort and offset pagination | | computed projection field | a calculation on the source resource | | role | an Ash.Policy.SimpleCheck per role on the resource actors are bound to with is (a private roles attribute and a calculation per role condition); policies that only name roles become authorize_if lines with Ash.Policy.Authorizer | | interface rest | AshJsonApi routes on the domain (index for queries with default_fields from picks, patch for update actions), served by Phoenix under /api/json when the model has pages, otherwise by a JSON:API router that Bandit serves on port 4000 | | page, navigation, messages | Phoenix LiveViews with lists, details, AshPhoenix forms and action buttons, navigation links and column labels; models with pages need the phx_new archive | | rules | skipped ExUnit tests in test/<app>/<module>/<resource>_test.exs for invariants, policies, transitions and preconditions; writing their bodies is a registry task |

The project ends with mix ash.codegen initial_resources, so migrations and resource snapshots start with the generated resources.

appling generate --migrate changes the attribute in the resource, writes an Ecto migration that renames, modifies or removes the column, and updates the resource snapshots with mix ash_postgres.generate_migrations --snapshots-only, so later mix ash.codegen runs do not see a rename as a drop and an add. Renamed entities and enum values become registry tasks.

Machines, scheduled jobs and REST interfaces add ash_state_machine, ash_oban, and ash_json_api with bandit to the project.

What cannot be translated becomes a registry task: many to many relationships, calculations over embedded lists, invariants and preconditions over calculations or other resources, policies that say more than which roles may act, events (Ash notifiers), externals and use cases (generic actions or Reactor), effects that create rows or emit events, jobs on events, authentication, rate limits and CORS.

License

MIT