user.ex

user.ex

defmodule MyApp.User do
  use MyApp.Web, :model

  schema "users" do
    field :username, :string
    field :email, :string
    field :password, :string, virtual: true
    field :password_confirmation, :string, virtual: true
    field :encrypted_password, :string

    timestamps
  end

  def changeset(model, action, params \\ nil) do
    model
    |> cast(params, required_fields_for(action), optional_fields_for(action))
    |> validate_password_confirmation
    |> set_hashed_password
  end

  defp required_fields_for(:create) do
    ~w(username email password password_confirmation)
  end

  defp required_fields_for(:update) do
    ~w(username email)
  end

  defp optional_fields_for(:create) do
    ~w()
  end

  defp optional_fields_for(:update) do
    ~w(password password_confirmation)
  end

  defp validate_password_confirmation(changeset) do
    password = Ecto.Changeset.get_field(changeset, :password, "")

    password_confirmation = Ecto.Changeset.get_field(changeset, :password_confirmation, "")

    case password do
      ^password_confirmation -> changeset
      _ -> Ecto.Changeset.add_error(changeset, :password, "must match confirmation")
    end
  end

  # Ignore for now that this isn't actually hashing anything.
  defp hash_password(password) do
    password <> "ABCDEFG"
  end

  defp set_hashed_password(changeset) do
    password = Ecto.Changeset.get_field(changeset, :password)

    case password do
      nil -> changeset
      pwd -> Ecto.Changeset.put_change(changeset, :encrypted_password, hash_password(pwd))
    end
  end
end

Interesting way of handling required and optional fields! 😄

Yeah, I'm digging these functions for required and optional fields!