在构建R包时如何设置常量变量? [英] How do we set constant variables while building R packages?

问题描述

我们正在R中为我们的服务(巴西的机器人顾问)构建一个程序包，并且我们始终将请求发送到我们函数内部的外部API.

We are building a package in R for our service (a robo-advisor here in Brazil) and we send requests all the time to our external API inside our functions.

因为这是我们第一次构建软件包，所以我们有一些疑问.:(

As it is the first time we build a package we have some questions. :(

当我们使用程序包运行某些脚本时，我们将需要一些信息，例如 api_path，登录名，密码.

When we will use our package to run some scripts we will need some information as api_path, login, password.

我们如何将这些信息放入我们的包裹中?

How do we place this information inside our package?

这是一个真实的例子:

get_asset_daily <- function(asset_id) {
    api_path <- "https://api.verios.com.br"

    url <- paste0(api_path, "/assets/", asset_id, "/dailies?asc=d")
    data <- fromJSON(url)
    data
}

有时我们使用API​​的 staging 版本，我们必须不断切换路径.我们应该如何在函数内部调用它?

Sometimes we use a staging version of the API and we have to constantly switch paths. How we should call it inside our function?

我们应该设置全局环境变量，程序包环境变量，只在脚本或程序包配置文件中定义 api_path 吗?

Should we set a global environment variable, a package environment variable, just define api_path in our scripts or a package config file?

我们该怎么做?

谢谢您的帮助.

安娜

推荐答案

一种方法是使用R的options接口.使用以下命令在R目录(此文件的惯用名称)中创建文件 zzz.r :

One approach would be to use R's options interface. Create a file zzz.r in the R directory (this is the customary name for this file) with the following:

.onLoad <- function(libname, pkgname) {
    options(api_path='...', username='name', password='pwd')

}

当程序包加载到内存中时，这将设置这些选项.

This will set these options when the package is loaded into memory.

这篇关于在构建R包时如何设置常量变量?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！