[Bug Report] Load MessageBox. confirm to report errors as needed

[H-Sven]

Element UI version

2.7.2

OS/Browsers version

chrome73

Vue version

2.6.10

Reproduction Link

https://jsfiddle.net/mmx38qxw/

Steps to reproduce

根据文档http://element-cn.eleme.io/#/zh-CN/component/quickstart 按需载入
import { MessageBox } from 'element-ui';

Vue.prototype.$alert = MessageBox.alert;
Vue.prototype.$confirm = MessageBox.confirm;

this.$alert(123) //正常
this.$confirm(message, options) // Uncaught ReferenceError: _MessageBox is not defined

What is Expected?

正常使用this.$confirm(message, options)

What is actually happening?

this.$confirm(message, options) 控制台报错 Uncaught ReferenceError: _MessageBox is not defined

[element-bot]

Translation of this issue:

Element UI version

2.7.2

OS/Browsers version

Chrome73

Vue version

2.6.10

Reproduction Link

https://jsfiddle.net/mmx38qxw/

Steps to reproduce

Load as needed according to the document http://element-cn.eleme.io/#/zh-CN/component/quickstart

Import {MessageBox} from'element-ui';
Vue. prototype. $alert = MessageBox. alert;

Vue. prototype. $confirm = MessageBox. confirm;
This. $alert (123)// Normal

This. $confirm (message, options) // Uncaught Reference Error: _MessageBox is not defined

What is Expected?

Use this. $confirm (message, options)

What is actually happening?

This. $confirm (message, options) console error Uncaught Reference Error: _MessageBox is not defined

[H-Sven]

按需引入MessageBox后，无法同时使用confirm message等方法

[luckyCao]

@Demohu 试了下没有重现，请提供一个可复现的 demo

[PanJiaChen]

ElementUI/babel-plugin-component#31