有多糟糕 - 内联js调用外部处理程序定义VS完全外部js [英] How bad it is - Inline js calls with external handlers definition VS totally external js

问题描述

我在我的项目中遇到以下代码：

I run into following code in my project:

html：

<input type="button" id="addmore" value="Add more" onclick="add_table(this)"/>

js：

function add_table(elem){
    var current_id = jQuery("table.t1:last").attr("id");

首先我认为这段代码错了，我必须将它重写为外部代码，即

First I thought that this code is wrong and I must rewrite it to external code, i.e.

jQuery('#addmore)'.click(function add_table(elem){
    var current_id = jQuery("table.t1:last").attr("id");

然后我再次查看它并发现这个html更具可读性 - 我看到哪些函数绑定到html中的哪些元素，我不需要在js中搜索它。

But then I looked at it again and found that this html is more readable - I see which functions binds to which elements already in html, and I don't need to search it in js.

当然不是封装在里面

jQuery(document).ready( 

因此在某些情况下不起作用

so it will not work under some circumstances

所以问：这段代码有多糟糕？

So question: how bad this code is?

推荐答案

这是一个可重用性和个人品味的问题。内联代码对于像你的例子这样非常简单的事情更具可读性，但当然你依赖于 add_table（）作为一个全局函数 - 如果你有数百个elem如果有不同的点击处理程序，最终可能会有数百个函数/变量污染全局命名空间。那太糟糕了！ ：）

It's a question re-usability and personal taste. Inline code is more readable for very simple things like your example, but of course you are relying on add_table() being a global function - if you have hundreds of elements with different click handlers, you could end up with hundreds of functions/variables polluting the global namespace. And that's bad! :)

在可重用性方面，我发现在抽象功能的不同组件中编码更好，并且可以在需要时调用 - 所有这些都在定义的内部（非-global）namespace。

In terms of re-usability, I find it better to code in distinct components that abstract functionality and can be called upon whenever needed - all within a defined (non-global) namespace.

jQuery('#addmore)'.click(function add_table(elem) {
    var current_id = jQuery("table.t1:last").attr("id");
}

上面的代码提供了一个很好的关注点分离 - 意思是语义信息（HTML）没有注意到行为信息（Javascript），这有助于创建更清晰，更易于管理的代码。

The code above gives a good separation of concerns - meaning the semantic information (HTML) is oblivious to the behavioural information (Javascript), which again helps create cleaner, more manageable code.

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