The macros of a definition module: options/1, routes/1 and pipeline/2.

They are imported by use PhoenixMountable.

Options

options/1 declares the options of the mount macro, as a NimbleOptions schema. They are validated when the host router compiles, and documented in the mount macro's docs.

options resolver: [
          type: :atom,
          default: MyLib.Resolver,
          verify: {:behaviour, MyLib.Resolver},
          doc: "The module that resolves the current user."
        ],
        features: [type: {:list, :atom}, default: []]

Besides the NimbleOptions keys, an option can have :verify: :module checks that the value names an existing module, and {:behaviour, mod} also checks that it implements mod (or is mod). The check runs after the host router compiles: a module that uses the host's verified routes depends on the router, so checking it while the router compiles would deadlock.

The values are in mount.options, a map with every declared option.

Routes

routes/1 declares the library's routes with the macros of PhoenixMountable.Routes, relative to the mount path:

routes do
  get "/export", MyLib.ExportController, :csv

  live_session :default, on_mount: [MyLib.Auth] do
    live "/", MyLib.HomeLive, :index
  end
end

Pipelines

pipeline/2 defines a pipeline of the library, like Phoenix.Router.pipeline/2, for its routes to pipe_through. It is compiled into a module plug, so the host needs nothing in its own router.

pipeline :api do
  plug :accepts, ["json"]
end