Some problems encountered in recent programming 2021 / 9 / 8

1
First of all el-autocomplete When this component makes a fuzzy query , To limit input to numbers , And limit the length of the input

				<el-autocomplete
                v-model="phoneNumber"
                :fetch-suggestions="querySearch"
                :maxlength="length"
                placeholder=" Please enter the contact number "
                oninput="value=value.replace(/[^\d]/g,'')"
                @select="handleSelect"
              />

Give her one maxlength attribute , But this must be a number , It doesn't work if it's not a number , So you can dynamically bind a number .
It can be used oninput Limit what is entered .

2
Intercepts a portion of a string

let str1=str.substring(0,ipos); // Take the front part （ Specify the beginning of the string before ）
//  For example, I need to intercept the first three characters of the string 
let str = 'abcdefg'
str.substring(0,3)
//  Back to you abc

3
element-UI Verification rules for license plate numbers （vue）

//  Written in data Inside 
var carPhoneValid = (rule, value, callback) => {
      const plateNumber = /^([ Beijing, Tianjin, Shanghai, Chongqing, Hebei, Henan, Yunnan, Liaoning, Heilongjiang, Hunan, Anhui, Shandong, new Jiangsu, Zhejiang, Jiangxi, Hubei, Guangxi, Gansu, Shanxi, Inner Mongolia, Shaanxi, Jilin, Fujian, Guizhou, Guangdong, Qinghai Tibet, Sichuan, Ningxia and Hainan A-Z]{1}[A-Z]{1}(([0-9]{5}[DF])|([DF]([A-HJ-NP-Z0-9])[0-9]{4})))|([ Beijing, Tianjin, Shanghai, Chongqing, Hebei, Henan, Yunnan, Liaoning, Heilongjiang, Hunan, Anhui, Shandong, new Jiangsu, Zhejiang, Jiangxi, Hubei, Guangxi, Gansu, Shanxi, Inner Mongolia, Shaanxi, Jilin, Fujian, Guizhou, Guangdong, Qinghai Tibet, Sichuan, Ningxia and Hainan A-Z]{1}[A-Z]{1}[A-HJ-NP-Z0-9]{4}[A-HJ-NP-Z0-9 Hang the school police in Hong Kong and Macao ]{1})$/
      if (!value) {
        callback(new Error(' Please enter the license plate number '))
      } else if (plateNumber.test(value)) {
        callback()
      } else {
        callback(new Error(' Wrong license plate number format '))
      }
    }
	// rules
 carNum: [
          { required: true, validator: carPhoneValid, trigger: 'blur' }
        ],

4
stay el-dialog Clear after closing el-form Validation rules for

to el-dialog Bind one @close="closeadd2Dialog" Method

closeadd2Dialog() {
      this.$refs.addNewForm.resetFields()
    },

5
You can write the tips you want

this.$message({
          message: ' Reason cannot be empty ',
          type: 'error'
        })

6
When /deep/ When it doesn't work , It can be used ::v-deep

::v-deep .el-textarea{
  width: 100%;
}

7
Use replace Function substitution

str = '2021-09-08T15:05:34.20'
// Remove a string contained in a string ：str = str.replace('T', ' ');
//  Here is the handle. T Replace with space 
// Get rid of T And milliseconds can be written as 
str.replace('T', ' ').substring(0, 19)

// Be careful ： You cannot write here ：str.replace(‘give’, ‘’); Writing ：str = str.replace(‘give’, ‘’);