在 node.js 应用程序中包含外部. js 文件

我有一个 app.js 节点应用程序。随着这个文件开始增长，我想将代码的一部分移动到 app.js 文件中的其他一些文件中，这些文件是我“需要”或“包含”的。

我在尝试这样的事情:

// Declare application
var app = require('express').createServer();


// Declare usefull stuff for DB purposes
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var ObjectId = Schema.ObjectId;


// THE FOLLOWING REQUIRE DOES NOT WORK
require('./models/car.js');

在 car.js:

// Define Car model
CarSchema = new Schema({
brand        : String,
type : String
});
mongoose.model('Car', CarSchema);

我搞错了:

ReferenceError: Schema is not defined

我只是希望加载 car.js 的内容(而不是将所有内容都放在同一个 app.js 文件中) ，在 node.js 中有没有特殊的方法来实现这一点？

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最佳答案

To place an emphasis on what everyone else has been saying var foo in top level does not create a global variable. If you want a global variable then write global.foo. but we all know globals are evil.

If you are someone who uses globals like that in a node.js project I was on I would refactor them away for as there are just so few use cases for this (There are a few exceptions but this isn't one).

// Declare application
var app = require('express').createServer();


// Declare usefull stuff for DB purposes
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var ObjectId = Schema.ObjectId;


require('./models/car.js').make(Schema, mongoose);

in car.js

function make(Schema, mongoose) {
// Define Car model
CarSchema = new Schema({
brand        : String,
type : String
});
mongoose.model('Car', CarSchema);
}


module.exports.make = make;
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you can put

var mongoose = require('mongoose');
var Schema = mongoose.Schema;

at the top of your car.js file for it to work, or you can do what Raynos said to do.

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The correct answer is usually to use require, but in a few cases it's not possible.

The following code will do the trick, but use it with care:

var fs = require('fs');
var vm = require('vm');
var includeInThisContext = function(path) {
var code = fs.readFileSync(path);
vm.runInThisContext(code, path);
}.bind(this);
includeInThisContext(__dirname+"/models/car.js");
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If you just want to test a library from the command line, you could do:

cat somelibrary.js mytestfile.js | node
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Short answer:

// lib.js
module.exports.your_function = function () {
// Something...
};


// app.js
require('./lib.js').your_function();
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This approach works for me in Node.js, Is there any problem with this one?

File 'include.js':

fs = require('fs');

File 'main.js':

require('./include.js');


fs.readFile('./file.json', function (err, data) {
if (err) {
console.log('ERROR: file.json not found...')
} else {
contents = JSON.parse(data)
};
})

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