为什么我不能在 node.js (browserify) 的 require() 函数中使用变量作为参数？

Question

I tried something like:

var path = '../right/here';
var module = require(path);

but it can't find the module anymore this way, while:

var module = require('../right/here');

works like a charm. Would like to load modules with a generated list of strings, but I can't wrap my head around this problem atm. Any ideas?

Answer 1

you can use template to get file dynamically.

var myModule = 'Module1';
var Modules = require(`../path/${myModule}`)

Answer 2

This is due to how Browserify does its bundling, it can only do static string analysis for requirement rebinding. So, if you want to do browserify bundling, you'll need to hardcode your requirements.

For code that has to go into production deployment (as opposed to quick prototypes, which you rarely ever bother to add bundling for) it's always advisable to stick with static requirements, in part because of the bundling but also because using dynamic strings to give you your requirements means you're writing code that isn't predictable, and can thus potentially be full of bugs you rarely run into and are extremely hard to debug.

If you need different requirements based on different runs (say, dev vs. stage testing vs. production) then it's usually a good idea to use process.env or a config object so that when it comes time to decide which library to require for a specific purposes, you can use something like

var knox = config.offline ? require("./util/mocks3") : require("knox");

That way your code also stays immediately traversable for others who need to track down where something's going wrong, in case a bug does get found.

Answer 3

require('@/path/'.concat(fileName))

Answer 4

您可以使用.require()添加要访问的文件，计算其路径而不是在构建时是静态的，这样这些模块将被包含在内，并且稍后调用require()时会找到它们。