Elixir Phoenix 将 JSON 解析为结构

Question

基于this answer，我知道如何使用Poison.decode/2将JSON解析为结构：

defmodule User do
  @derive [Poison.Encoder]
  defstruct [:address]
end

defmodule Address do
  @derive [Poison.Encoder]
  defstruct [:street]
end

Poison.decode(response, as: %User{address: %Address{}})

但是我如何告诉菲尼克斯也这样做呢？如果我告诉它我的端点接受 JSON，它会自动将其解析为地图：

defmodule MyAppWeb.Router do
  use MyAppWeb, :router

  pipeline :api do
    plug :accepts, ["json"]
  end

  scope "/api/v1", MyAppWeb do
    pipe_through :api

    put "/endpoint", MyController, :put
  end
end

defmodule MyController do
  def put(conn, %{"_json" => map}) do
    # Here, `map` is already parsed as a map. How can I tell Phoenix to
    # parse it as a struct I choose like I can tell `Poison` to do so?
  end
end

Answer 1

在您的endpoint.ex 中，您应该有parsers 插头：

 plug Plug.Parsers,
    parsers: [:urlencoded, :multipart, :json],
    pass: ["*/*"],
    json_decoder: Poison

删除 json 原子，这应该禁用 json 解析器。