mix phx.gen.live (Phoenix v1.8.1)

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Generates LiveView, templates, and context for a resource.

The format is:

$ mix phx.gen.live [<context>] <schema> <table> <attr:type> [<attr:type>...]

For example:

$ mix phx.gen.live User users name:string age:integer

Will generate a User schema for the users table within the Users context, with the attributes name (as a string) and age (as an integer).

You can also explicitly pass the context name as argument, whenever the context is well defined:

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

The first argument is the context module (Accounts) followed by the schema module (User), table name (users), and attributes.

The context is an Elixir module that serves as an API boundary for the given resource. A context often holds many related resources. Therefore, if the context already exists, it will be augmented with functions for the given resource.

The schema is responsible for mapping the database fields into an Elixir struct. It is followed by a list of attributes with their respective names and types. See mix phx.gen.schema for more information on attributes.

Overall, this generator will add the following files to lib/:

  • a context module in lib/app/accounts.ex for the accounts API
  • a schema in lib/app/accounts/user.ex, with a users table
  • a LiveView in lib/app_web/live/user_live/show.ex
  • a LiveView in lib/app_web/live/user_live/index.ex
  • a LiveView in lib/app_web/live/user_live/form.ex
  • a components module in lib/app_web/components/core_components.ex if none exists

After file generation is complete, there will be output regarding required updates to the lib/app_web/router.ex file.

Add the live routes to your browser scope in lib/app_web/router.ex:

  live "/users", UserLive.Index, :index
  live "/users/new", UserLive.Form, :new
  live "/users/:id", UserLive.Show, :show
  live "/users/:id/edit", UserLive.Form, :edit

Scopes

If your application configures its own default scope, then this generator will automatically make sure all of your context operations are correctly scoped. You can pass the --no-scope flag to disable the scoping.

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 Accounts User users --context-app my_app

Web namespace

By default, the LiveView modules are defined within a folder named after the schema, such as lib/app_web/live/user_live. You can add additional namespaces by passing the --web flag with a module name, for example:

$ mix phx.gen.live Accounts User users --web Accounts name:string

Which would generate the LiveViews in lib/app_web/live/accounts/user_live/, namespaced AppWeb.Accounts.UserLive instead of AppWeb.UserLive.

Customizing the context, schema, tables and migrations

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

$ mix phx.gen.live Accounts User users --no-context name:string

In the cases above, tests are still generated, but they will all fail.

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