如何在Node.js require()中的另一个模块中使用一个模块功能 [英] How to Use one module feature within another module in nodejs require()

问题描述

我想在另一个模块中使用一个模块功能

I want to use one module feature within another module

文件main.js

var _ = require("./underscore.js");
var foo = require("./bar.js");
foo.publish(...);

文件bar.js

(function(e) {
    var array = [...];
    e.publish = function(t, args) {
        _.each(array, function(...) {...});
    });
})(exports);

我尝试了几种变体，但是我不确定解决此错误的最佳方法:

I've tried a couple of variations, but I am not sure of the best way around this error:

ReferenceError: _ is not defined

推荐答案

是的，对于您的示例，应该在每个需要该变量的模块中使用.

Yes, you should use in every module which needs that variable, for the case of you example.

var _ = require("./underscore.js");

但是，如果您需要在多个模块之间转移一个对象实例，则可以使用 process 对象将其变为全局对象.但这是不好的做法.

But if you need to transfer one object instance between several modules you can use process object to make it global. But that is BAD practice.

process._ = require("./underscore.js");

在模块之间传递对象实例的好方法是将它们作为函数参数传递，但是您需要更改bar.js以返回工厂函数，而不是对象本身.

Good way to pass object instances between the modules is to pass them as function arguments, but you need to change you bar.js to return a factory function, not an object itself.

module.exports = function(_) {
   var e = {};
   var array = [...];
   e.publish = function(t, args) {
      _.each(array, function(...) {...});
   });
   return e;
}

在main.js中:

var _ = require("./underscore.js");
var foo = require("./bar.js")(_);
foo.publish(...);

我希望你明白这一点.

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