[Bug Report] inputNumber data cannot be displayed synchronously

[yuminjustin]

Element UI version

2.4.5

OS/Browsers version

win10/chromium 63

Vue version

2.5.17

Reproduction Link

http://jsfiddle.net/L3w6mrt2/2//

Steps to reproduce

链接中的示例：手动输入1.6，进入绑定的change事件中，把组件state改成非浮点数。由于初始值就是1，输入的1.6，使用Math.floor的方法将值改成了1，组件的test实际为1，但界面依然是1.6。除非另外输入2.6，界面就会显示成2。

What is Expected?

其实我就是新作一个禁止输入浮点数的功能

What is actually happening?

当change事件中经过处理后的值跟原来的值相同时，无法变更界面显示。

[element-bot]

Translation of this issue:

Element UI version
2.4.5

OS/Browsers version
Win10/chromium 63

Vue version
2.5.17

Reproduction Link
http://jsfiddle.net/L3w6mrt2/2//

Steps to reproduce
Example in the link: manually enter 1.6, enter the change event of the binding, and change the component state to a non floating point number. Since the initial value is 1 and the input value is 1.6, the value is changed to 1 using the Math. floor method. The test of the component is actually 1, but the interface is still 1.6. Unless another 2.6 is entered, the interface will display 2.

What is Expected?
In fact, I am the new function of prohibiting the importation of floating point numbers.

What is actually happening?
The interface display can not be changed when the processed value in the change event is the same as the original value.

[yuminjustin]

刚才尝试一下把change事件做了一下改变：

        handleNum(value) {
            this.test = value * 100;
            setTimeout(() => {
                if (!/^[1-9]\d*$/.test(value)) {
                    this.test = Math.floor(value);
                }
            }, 10)

        }

可以达到目的，但是感觉这样太low了

[ziyoung]

只输入整数吗？试试设置 precision 属性。https://jsfiddle.net/zhiyang/yt6cm0e1/

[yuminjustin]

@ziyoung 你的例子的确可以用，但是很奇怪 precision = 0
官方文档里面：http://element-cn.eleme.io/#/zh-CN/component/input-number

precision的值必须是一个正整数
。。。。。。。
所以我都没去用这个

[ziyoung]

@yuminjustin 文档描述的有问题😅，precision 应该是大于或者等于 0 的整数才对。

element/packages/input-number/src/input-number.vue

Lines 94 to 97 in 8de71d0

	precision: {
	type: Number,
	validator(val) {
	return val >= 0 && val === parseInt(val, 10);