mix task added: mix paper_trail.install

lib/mix/tasks/papertrail/install.ex

@@ -1,9 +1,41 @@
 defmodule Mix.Tasks.Papertrail.Install do
-  @shortdoc "my short doc"
+  @shortdoc "generates paper_trail migration file for your database"
+
+  import Macro, only: [camelize: 1, underscore: 1]
+  import Mix.Generator
 
   use Mix.Task
 
   def run(args) do
-    IO.puts "run called"
+    path = Path.relative_to("priv/repo/migrations", Mix.Project.app_path)
+    file = Path.join(path, "#{timestamp()}_#{underscore(AddVersions)}.exs")
+    create_directory path
+
+    create_file file, """
+    defmodule Repo.Migrations.AddVersions do
+      use Ecto.Migration
+
+      def change do
+        create table(:versions) do
+          add :event,        :string
+          add :item_type,    :string
+          add :item_id,      :integer
+          add :item_changes, :map
+          add :meta,         :map
+          add :originator,   :string
+
+          add :inserted_at,  :datetime, null: false
+        end
+      end
+    end
+    """
   end
+
+  defp timestamp do
+    {{y, m, d}, {hh, mm, ss}} = :calendar.universal_time()
+    "#{y}#{pad(m)}#{pad(d)}#{pad(hh)}#{pad(mm)}#{pad(ss)}"
+  end
+
+  defp pad(i) when i < 10, do: << ?0, ?0 + i >>
+  defp pad(i), do: to_string(i)
 end

mix.exs

@@ -40,7 +40,7 @@ defmodule PaperTrail.Mixfile do
       maintainers: ["Izel Nakri"],
       licenses: ["MIT License"],
       links: %{
-        # "GitHub" => "https://github.com/ericmj/postgrex",
+        "GitHub" => "https://github.com/izelnakri/paper_trail"
         # "Docs" => "http://ericmj.github.io/postgrex/"
       }
     ]