如何从Phoenix的环境文件中获取变量值? [英] How to get a variable value from Environment files in Phoenix?

问题描述

我正在部署我的第一个Phoenix应用程序，并且已经在我的环境文件(dev.exs和prod.exs)中指定了变量的值.

I'm deploying my first Phoenix Application, and I've specified the values of a variable in my Environment Files (dev.exs and prod.exs).

现在，我正在尝试弄清楚如何在我的控制器中访问它们.

Now I'm trying to figure out how to access them in my Controllers.

# config/dev.exs
config :my_app, MyApp.Endpoint,
  http: [port: 4000],
  debug_errors: true,
  cache_static_lookup: false,
  my_var: "DEVELOPMENT VALUE"

# config/prod.exs
config :my_app, MyApp.Endpoint,
  http: [port: {:system, "PORT"}],
  url: [host: "example.com"],
  my_var: "PRODUCTION VALUE"

推荐答案

好的，发现了一些东西. 长生不老药 Application.get_env/3是必经之路:

Okay, found something. Elixir's Application.get_env/3 is the way to go:

get_env(应用程序，密钥，默认\\无)

get_env(app, key, default \\ nil)

---

但是问题在于，对于当前情况，accessor命令变得很长:

---

But the problem with this is that the accessor command becomes very long for the current situation:

# Set value in config/some_env_file.exs
config :my_large_app_name, MyLargeAppName.Endpoint,
  http: [port: {:system, "PORT"}],
  url: [host: "example.com"],
  my_var: "MY ENV VARIABLE"

# Get it back
Application.get_env(:my_large_app_name, MyLargeAppName.Endpoint)[:my_var]

---

一种更好的方法 是在单独的部分中对其进行定义:

---

A better way would be to define them in a separate section:

config :app_vars,
  a_string: "Some String",
  some_list: [a: 1, b: 2, c: 3], 
  another_bool: true

并像这样访问它们:

Application.get_env(:app_vars, :a_string)
# => "Some String"

或者您可以获取所有键值对的list:

Or you could fetch a list of all key-value pairs:

Application.get_all_env(:app_vars)           
# => [a_string: "Some String", some_list: [a: 1, b: 2, c: 3], another_bool: true]

这篇关于如何从Phoenix的环境文件中获取变量值?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！