覆盖 jQuery .val() 函数?

问题描述

有没有办法轻松覆盖 jQuery 的 val() 函数?

Is there a way to easily override jQuery's val() function?

我想覆盖它的原因是我想在每次为元素设置值时添加一些处理.而且我不想制作另一个自定义值设置器，例如 myVal().

The reason I want to override it is that I want to add some processing each time a value is set for an element. And I don't want to make another custom value setter, such as myVal().

推荐答案

我知道这是一个古老的主题，但它在谷歌搜索中是第一个，答案并不完全正确......

I know it's an old subject but it's first in google search and the answer is not completely right...

例如，如果你在控制台中尝试 $('#myinput').val() 你应该得到 #myinput 的值.

For example if you try in the console $('#myinput').val() you should get the value of #myinput.

但是如果你这样做 $('#myinput').val(undefined) 你应该设置 #myinput!(使用当前答案及其评论，您将不会设置#myinput的值)

But if you do $('#myinput').val(undefined) you should set the value of #myinput!(With the current answer and the comments of it, you will not set the value of #myinput)

这是使用 arguments 的升级答案.

Here is an upgraded answer that use arguments.

(function ($) {
  var originalVal = $.fn.val;
  $.fn.val = function(value) {
    if (arguments.length >= 1) {
      // setter invoked, do processing
      return originalVal.call(this, value);
    }
    //getter invoked do processing
    return originalVal.call(this);
  };
})(jQuery);

如果你想传递所有参数，你也可以使用 apply

if you want to pass all the arguments you can also use apply

(function ($) {
  var originalVal = $.fn.val;
  $.fn.val = function(value) {
    if (arguments.length >= 1) {
      // setter invoked, do processing
    } else {
      //getter invoked do processing
    }
    return originalVal.apply(this, arguments);
  };
})(jQuery);

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