How to Log something in Controller when Phoenix Server is running?

elixir phoenix-framework
Sheharyar picture Sheharyar · Jun 20, 2015 · Viewed 24.4k times · Source

I'm trying to print some debug information from one of my Controllers in my Phoenix app when the server is running.

defmodule PhoenixApp.TopicController do
  use PhoenixApp.Web, :controller

  def index(conn, _params) do
    log("this text")

    # ... 
  end
end

Answer

Sheharyar picture Sheharyar · Jun 20, 2015

Okay, turns out it's pretty straight forward. You need to require the Logger elixir module in your controller and call one of it's methods to log your text.

defmodule PhoenixApp.TopicController do
    require Logger

    def index(conn, params) do
        Logger.info  "Logging this text!"
        Logger.debug "Var value: #{inspect(params)}"

        # ...
    end
end

Supported levels are:

  • :debug - for debug-related messages
  • :info - for information of any kind
  • :warn - for warnings
  • :error - for errors

Source: Elixir - Logger Documentation

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