bb40SDyh

1defmodule PrefixID do
2
3  @doc """
4  Custom Ecto.Type use macro
5
6  Example:
7
8      use PrefixID, prefix: "secret_key"
9
10  After this, the Ecto type will have
11  all features defined below.
12  """
13  defmacro __using__(opts) do
14    prefix = opts[:prefix] || "test"
15
16    quote bind_quoted: [prefix: prefix] do
17      @behaviour Ecto.Type
18
19      def type, do: :string
20
21      def cast(string) when is_binary(string) do
22        {:ok, string}
23      end
24
25      defp prepared_prefix do
26        unquote(prefix) <> "_"
27      end
28
29      def autogenerate() do
30        prepared_prefix() <> Random.base58()
31      end
32
33      def cast(_), do: :error
34
35      def dump(string) when is_binary(string) do
36        {:ok, string}
37      end
38
39      def load(string) when is_binary(string) do
40        {:ok, string}
41      end
42    end
43  end
44end