Using El date picker to report errors in sub components

Report errors ：

Avoid mutating a prop directly since the value will be overwritten whenever the parent component re-renders. Instead, use a data or computed property based on the prop's value. Prop being mutated: "placement"
 

Note that this is only used in sub components el-date-picker Solutions for , This is because the current hungry version is too high and incompatible

The first step is to uninstall the original elementUI edition

npm uninstall element-ui

Reduce version

npm install [email protected] -s