Basic elements of Element form validation in Vue

This article mainly introduces the basic elements of Element form validation in Vue. It has certain reference value. Now I share it with you. Friends in need can refer to it.

Element mainly uses async-validator This library serves as form validation

async-validatorIt is mainly divided into three parts

• Validate

• Options

• Rules

Among them, Rules is the most important for us to use Element, and it is also the part with the most content.

Parts of async-validator

Basic use of async-validator

import Validator from 'async-validator'

// 规则的描述
const rules = {
  name: { type: 'string', required: true }
}

// 根据规则生成验证器
const validator = new Validator(rules)

// 要验证的数据源
const source = {
  name: 'LanTuoXie'
}

// 验证后的回调函数
function callback (errors, fileds) {
  if (errors) {
    // 验证不通过，errors是一个数组，记录那些不通过的错误信息
    // fileds是所有数据源的字段名，也即上面的source的'name'
    // 验证是根据字段名来的，rules.name 对应 source.name。 字段名要一样才会验证
  }
  // 下面是验证通过的逻辑
}

// 验证数据源是否符合规则
validator.validate(source, callback)

Validate

is the above The validator.validate in the example is a function

function(source, [options], callback)

source and callback corresponding to the above example.

Options

Options has two values ​​

• first: A Boolean value, if present If the field does not pass, the verification of the following fields will be terminated.

• firstFields: Boolean value or string. If a rule does not pass when validating a field, the verification of the next field will be terminated. Rules (one field, multiple rules)

firstFields is used when there are multiple rules for a single field, while first is For all fields

Rules

the most important one is Rules. Rules can be defined in three forms, but the rules field name must be consistent with the field name of the data source.

• Function method: { name(rule, value, callback, source, options) {} }

• Object method: { name: { type: 'string', required: true } }

• Array method: { name: [{ type : 'string' }, { required: true }] }

As you can see above, the field name name can be defined in three ways. When using Element, it is still The object and array methods are recommended, these two are relatively simple, and the function should be used according to the situation.

In addition to type and required, what other usages can be used and what are their uses?

Default rules for Rules

• type: The type of data to be verified such as url and number etc

• required: Is it required?

• pattern: Use regular expressions to Verification

• min: Minimum value of data length (data type must be string or array)

• max: The maximum length of data (the data type must be string or array)

• len: The length of the data must be equal to this value (the data type must be string or array)

• enum: The value of the data must be equal to a certain element of this enumeration array{ enum: [1, 2, 3] }

• transform: A hook function that can process the data and then verify it before starting the verification. For example, convert number to string and then verify

• message: The error message can be a string or a jsx tag<span>Name is required</span>

• validator: Custom verification function and error message validator(rule, value, callback)

• There is also a Deep Rules that handles the object or array type, using fields or defaultField

• fields: Used when using Deep Rules to define the field names and rules of the next layer

• defaultField: Deep Used when using Rules, all fields at the next level will adopt this rule and can be replaced by fields

Default Type

• string: Must be of String type. If the rule does not set the type, the default is this

• number: Must be of Number type. If the background The returned data is a string, which can be converted to Number type using transform. String type numbers ('12') will not pass. Please note that

• boolean: Must be of Boolean type

• method: Must be Function

• regexp : Must be a regular RegExp

• integer: It is a positive integer of Number type

• float : It is a floating point number of type Number

• array: It is the array passed by Array.isArray

• object: Object type that Array.isArray does not pass

• enum: Enum must be defined first, and then the value must be a certain value of enum

• date: Must be an instance of Date object

• url: String type and conforms to the link format

• hex

• ##email: String type, and conforms to the email format

Deep Rules使用demo

cosnt urls = ['http://www.baidu.com', 'http://www.baidu.com']
// 一个urls的数组，
const rules = {
  urls: {
    type: 'array',
    required: true,
    defaultField: { type: 'url' }
  }
}

const ids = {
  name: 'LanTuoXie',
  age: 12,
  spc: '帅'
}

const rules = {
  ids: {
    type: 'object',
    required: true,
    fields: {
      name: { type: 'string', required: true },
      age: { type: 'number', required: true, tranform: Number },
      spc: { type: 'string', required: true }
    }
  }
}

自定义验证validator

validator(rule, value, callback)

• rule: 记录了验证字段的字段名以及规则的信息

• value: 要验证的值

• callback: 如果callback()代表验证通过，如果callback(new Error('错误要提示的信息'))代表验证不通过

// 验证是[min, max]范围内的正整数
const betweenInt = (min, max) => (rule, v, cb) => {
  const isBetween = v >= min && v <= max
  const isInt = /^[0-9]+$/.test(v)
  if (isBetween && isInt) return cb()

  return cb(new Error(`要求是在${min}到${max}的正整数 [${min}, ${max}]`))
}

const rules = {
  num: { validator: betweenInt(1, 5), required: true }
}

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