从另一个模块使用GenServer

时间:2018-10-14 16:17:19

标签: elixir

我有一个简单的GenServer,它在这里:

GenServer:

defmodule MyApp.ScoreTableQueue do
  use GenServer

  @impl true
  def init(stack) do
    {:ok, stack}
  end

  @impl true
  def handle_call(:pop, _from, state) do
    {:reply, state, []}
  end

  @impl true
  def handle_cast({:push, item}, state) do
    {:noreply, [item | state]}
  end
end

我想在此模块中使用此GenServer:

模块:

  defp order_score(question, season) do
    for team <- season.teams do
      state = score_table_map(question, team)

      # Push state on GenServer queue
    end

    create_score_table(question, season)
  end

  defp score_table_map(question, team) do
    p_score = Enum.find(team.prediction_scores, &(&1.question_id == question.id))
    %{team_score: p_score.score, team_id: p_score.team_id}
  end

  defp create_score_table(question, season) do
    changeset = ScoreTable.changeset(%ScoreTable{
      question_id: question.id,
      season_id: season.id,
      table_details: %{
        information: # Pop state of genserver
      }
    })

    Repo.insert(changeset)
  end

如该代码示例中所指出的,我想在GenServer上的循环过程中以及在下面的变更集上弹出状态后,将某些状态推入。

我的主要问题是如何在其他模块中初始化genserver,这是最佳实践吗?

1 个答案:

答案 0 :(得分:4)

您将不想在另一个模块中初始化GenServer。您将需要将其添加到您的监督树中。

您可能还想考虑将“ API”功能添加到GenServer模块,以便其用户不需要知道它是GenServer。像

# This assumes you have named your GenServer the same as the module name
def push(item) do
  GenServer.call(__MODULE__, {:push, item})
end

def pop() do
  GenServer.call(__MODULE__, :pop)
end

然后,您可以像需要的普通函数一样调用它。

MyApp.ScoreTableQueue.push(:foo)
stack = MyApp.ScoreTableQueue.pop()
...