不能要求全局npm模块 [英] Can’t require global npm module

问题描述

我有以下问题。我用 npm install -g uuid 安装uuid。
当我尝试运行以下代码时：

I have the following problem. I install uuid with npm install -g uuid. When I try to run the following code:

var uuid = require("uuid");
console.log(uuid.v1());

抛出异常：

module.js:339
throw err;
^

Error: Cannot find module 'uuid'
at Function.Module._resolveFilename (module.js:337:15)
at Function.Module._load (module.js:287:25)
at Module.require (module.js:366:17)
at require (module.js:385:17)
at Object.<anonymous> (d:\CodingProjects\HTML\TestJavascript.js:16:12)
at Module._compile (module.js:435:26)
at Object.Module._extensions..js (module.js:442:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:311:12)
at Function.Module.runMain (module.js:467:10)

如果我在本地安装模块 npm install uuid 它运行正常。
但是为什么呢？我应该怎么做才能使我的全球包工作？
我试图从语言&框架 - > Javascript - >库，但如果我没有在我的项目本地安装它，我仍然会遇到异常。

If I install the module locally with npm install uuid it works fine. But why is that? What should I do, to make my global packages working? I tried to download it from Language & Frameworks -> Javascript -> Libraries, but I still get an exception if I don't install it locally for my project.

提前致谢。

推荐答案

原因在于如何 npm 安装包。

当您运行 npm install -g< package> 时，您告诉 npm 全局安装< package> 。当您想要将程序包用作命令行工具时，例如 Gulp ：

When you run npm install -g <package>, you tell npm to install the <package> globally. This works when you want to use the package as a command line tool, like, for example, Gulp:

$ npm install -g gulp
$ cd path/to/project
$ gulp

但是，如果您想依赖包裹，这不起作用。

However, this does not work when you want to depend on a package.

要依赖包，你应该在本地安装，i。即在项目目录中。这是 npm 的主要优点之一：本地安装可以更轻松地管理依赖关系和升级它们。没有 -g 标志的 npm install 命令专用于此。当你运行

To depend on a package, you should install it locally, i. e. in the project directory. This is one of the npm’s key benefits: local installation makes managing dependencies and upgrading them much easier for you. The npm install command without -g flag is dedicated exactly for that. When you run

$ npm install uuid

in，例如， foo 目录，创建 foo / node_modules 目录，并在那里安装 uuid 模块。之后，您可以在 foo 目录（或其任何子目录）中创建 .js 文件，并要求 uuid 模块，一切正常。

in, say, foo directory, a foo/node_modules directory is created, and uuid module is installed there. After that, you could create a .js file in the foo directory (or any its subdirectory), require the uuid module from it, and everything will work.

至于WebStorm：从语言和版本下载库。框架→Javascript→库实际上并没有下载 npm 包，它只是下载并安装库类型定义。类型定义有助于在代码中使用库时，WebStorm可以构建更好的自动完成功能。

As to WebStorm: downloading a library from Language & Frameworks → Javascript → Libraries does not actually download an npm package, it just downloads and installs the library type definitions. Type definitions help WebStorm build better autocompletion when you use a library in your code.

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