Elixir phoenix problem

123.ex

defmodule Hangman.MasterCatController do
  use Hangman.Web, :controller

  alias Hangman.MasterCat

  def index(conn, _params) do
    query = from p in MasterCat,
         select: p

    a = Repo.all(query)
    render conn, "index.json", mastercats: a
  end

  def create(conn, %{ "mastercats" => params }) do
    IO.inspect(params)
    a = MasterCat.changeset(%MasterCat{},params)
    Repo.insert(a)
    text(conn, a.valid?)
  end

end

defmodule Hangman.MasterCat do
  use Hangman.Web, :model

  schema "mastercats" do
    field :name, :string

    has_many :categories, Hangman.Category
  end

  @required_fields ~w(name )
  @optional_fields ~w()

  def changeset(model, params \\ :empty) do
    model
    |> cast(params, @required_fields, @optional_fields)
  end
end


defmodule Hangman.MasterCatView do
  use Hangman.Web, :view

  alias Hangman.MasterCat

  def render("index.json", %{ "assigns" => params }) do
    params
  end

  def render("index.json", params ) do
    IO.inspect(params)
    "co sie spierdolilo"
  end

end