An Ecto.Type that handles the conversion between a Markdown-formatted string in the database and a AtomTweaks.Markdown struct in memory.

Use this as the type of the database field in the schema:

defmodule AtomTweaks.Tweaks.Tweak do
  use Ecto.Schema

  schema "tweaks" do
    field :title, :string
    field :code, :string
    field :type, :string
    field :description, AtomTweaks.Ecto.Markdown
    belongs_to :user, AtomTweaks.Accounts.User, foreign_key: :created_by, type: :binary_id

    timestamps()
  end
end

All other references in the codebase should be to the AtomTweaks.Markdown module. See that module's documentation on how it is used.

See: Beyond Functions in Elixir: Refactoring for Maintainability for details on this pattern.