我正在用JavaScript客户端(在浏览器中运行)和Node.js服务器创建一个小应用程序,使用WebSocket通信。
我想在客户机和服务器之间共享代码。我才刚刚开始使用Node.js,至少可以说,我对现代JavaScript的知识有点生疏。因此,我仍然对CommonJS的require()函数感到困惑。如果我通过使用“export”对象创建我的包,那么我无法看到我如何在浏览器中使用相同的JavaScript文件。
我想创建一组在两端使用的方法和类,以方便编码和解码消息以及其他镜像任务。然而,Node.js/CommonJS打包系统似乎阻止了我创建可以在双方使用的JavaScript文件。
我还尝试使用JS.Class来获得更紧密的OO模型,但我放弃了,因为我不知道如何让提供的JavaScript文件与require()一起工作。我是不是遗漏了什么?
在浏览器的Node.js模块模式、AMD模块模式和全局模式中检查jQuery源代码:
(function(window){
var jQuery = 'blah';
if (typeof module === "object" && module && typeof module.exports === "object") {
// Expose jQuery as module.exports in loaders that implement the Node
// module pattern (including browserify). Do not create the global, since
// the user will be storing it themselves locally, and globals are frowned
// upon in the Node module world.
module.exports = jQuery;
}
else {
// Otherwise expose jQuery to the global object as usual
window.jQuery = window.$ = jQuery;
// Register as a named AMD module, since jQuery can be concatenated with other
// files that may use define, but not via a proper concatenation script that
// understands anonymous AMD modules. A named AMD is safest and most robust
// way to register. Lowercase jquery is used because AMD module names are
// derived from file names, and jQuery is normally delivered in a lowercase
// file name. Do this after creating the global so that if an AMD module wants
// to call noConflict to hide this version of jQuery, it will work.
if (typeof define === "function" && define.amd) {
define("jquery", [], function () { return jQuery; });
}
}
})(this)
如果你使用模块捆绑器(如webpack)来捆绑JavaScript文件以便在浏览器中使用,你可以简单地重用你的Node.js模块用于在浏览器中运行的前端。换句话说,你的Node.js模块可以在Node.js和浏览器之间共享。
例如,你有下面的代码sum.js:
普通Node.js模块:sum.js
const sum = (a, b) => {
return a + b
}
module.exports = sum
使用Node.js中的模块
const sum = require('path-to-sum.js')
console.log('Sum of 2 and 5: ', sum(2, 5)) // Sum of 2 and 5: 7
在前端重用它
import sum from 'path-to-sum.js'
console.log('Sum of 2 and 5: ', sum(2, 5)) // Sum of 2 and 5: 7
在浏览器的Node.js模块模式、AMD模块模式和全局模式中检查jQuery源代码:
(function(window){
var jQuery = 'blah';
if (typeof module === "object" && module && typeof module.exports === "object") {
// Expose jQuery as module.exports in loaders that implement the Node
// module pattern (including browserify). Do not create the global, since
// the user will be storing it themselves locally, and globals are frowned
// upon in the Node module world.
module.exports = jQuery;
}
else {
// Otherwise expose jQuery to the global object as usual
window.jQuery = window.$ = jQuery;
// Register as a named AMD module, since jQuery can be concatenated with other
// files that may use define, but not via a proper concatenation script that
// understands anonymous AMD modules. A named AMD is safest and most robust
// way to register. Lowercase jquery is used because AMD module names are
// derived from file names, and jQuery is normally delivered in a lowercase
// file name. Do this after creating the global so that if an AMD module wants
// to call noConflict to hide this version of jQuery, it will work.
if (typeof define === "function" && define.amd) {
define("jquery", [], function () { return jQuery; });
}
}
})(this)