user_form.ex

defmodule Brando.Form.UserForm do
  use Brando.Form
  import Brando.Router.Helpers

  def get_status_choices do
    [[value: "0", text: "Choice 1"],
     [value: "1", text: "Choice 2"]]
  end

  form "user", [method: "POST", action: admin_user_path(:create)] do
    field :full_name, :text,
      [required: true,
       label: "Full name"]
    field :username, :text,
      [required: true,
       label: "Username"]
    field :email, :email,
      [required: true,
       label: "Email"]
    field :password, :password,
      [required: true,
       label: "Password"]
    field :administrator, :checkbox,
      [label: "Administrator",
       default: false]
    field :editor, :checkbox,
      [label: "Editor",
       default: true]
    field :status, :select,
      [choices: quote do Brando.Form.UserForm.get_status_choices end,
       default: "1",
       label: "Status"]
    submit "Save user!",
      [class: "btn btn-default"]
  end
end