View Source mix phx.gen.html (Phoenix v1.7.12)

Generates controller with view, templates, schema and context for an HTML resource.

mix phx.gen.html Accounts User users name:string age:integer

The first argument, Accounts, is the resource's context. A context is an Elixir module that serves as an API boundary for closely related resources.

The second argument, User, is the resource's schema. A schema is an Elixir module responsible for mapping database fields into an Elixir struct. The User schema above specifies two fields with their respective colon-delimited data types: name:string and age:integer. See mix phx.gen.schema for more information on attributes.

Note: A resource may also be split over distinct contexts (such as Accounts.User and Payments.User).

This generator adds the following files to lib/:

  • a controller in lib/my_app_web/controllers/user_controller.ex
  • default CRUD HTML templates in lib/my_app_web/controllers/user_html
  • an HTML view collocated with the controller in lib/my_app_web/controllers/user_html.ex
  • a schema in lib/my_app/accounts/user.ex, with an users table
  • a context module in lib/my_app/accounts.ex for the accounts API

Additionally, this generator creates the following files:

  • a migration for the schema in priv/repo/migrations
  • a controller test module in test/my_app/controllers/user_controller_test.exs
  • a context test module in test/my_app/accounts_test.exs
  • a context test helper module in test/support/fixtures/accounts_fixtures.ex

If the context already exists, this generator injects functions for the given resource into the context, context test, and context test helper modules.

Umbrella app configuration

By default, Phoenix injects both web and domain specific functionality into the same application. When using umbrella applications, those concerns are typically broken into two separate apps, your context application - let's call it my_app - and its web layer, which Phoenix assumes to be my_app_web.

You can teach Phoenix to use this style via the :context_app configuration option in your my_app_umbrella/config/config.exs:

config :my_app_web,
  ecto_repos: [Stuff.Repo],
  generators: [context_app: :my_app]

Alternatively, the --context-app option may be supplied to the generator:

mix phx.gen.html Sales User users --context-app my_app

If you delete the :context_app configuration option, Phoenix will automatically put generated web files in my_app_umbrella/apps/my_app_web_web.

If you change the value of :context_app to :new_value, my_app_umbrella/apps/new_value_web must already exist or you will get the following error:

** (Mix) no directory for context_app :new_value found in my_app_web's deps.

Web namespace

By default, the controller and HTML view will be namespaced by the schema name. You can customize the web module namespace by passing the --web flag with a module name, for example:

mix phx.gen.html Sales User users --web Sales

Which would generate a lib/app_web/controllers/sales/user_controller.ex and lib/app_web/controllers/sales/user_html.ex.

Customizing the context, schema, tables and migrations

In some cases, you may wish to bootstrap HTML templates, controllers, and controller tests, but leave internal implementation of the context or schema to yourself. You can use the --no-context and --no-schema flags for file generation control.

You can also change the table name or configure the migrations to use binary ids for primary keys, see mix phx.gen.schema for more information.