How vue3+async-validator implements form validation

Build a vue3 project

Before creating the project, the first thing we need to explain here is the version we use

• Nodejs: v17.5.0

• ##pnpm: 7.0.0

• Vue: 3.2.25

First of all, we Vite creates a vue3 project demo named

FormValidate, we Enter the command

pnpm create vite FormValidate on the command line and press Enter

Then select vue

and continue to press Enter, indicating that we have initially created

FormValidate (Form Validation) Project

According to the command line prompts, we enter the project root directory, and then use the command

pnpm install to install the dependencies required for the project. Of course, pnpm is used here. Much faster than npm or yarn.

Next, we start the project

pnpm run dev, and the output in the terminal is as shown in the figure

 vite v2.9.7 dev server running at:
  > Local: http://localhost:3000/
  > Network: use `--host` to expose
  ready in 954ms.

Start browsing and enter the address

http://localhost:3000 /

ok, here we have set up the project. At the end of the day, we will start to talk about our topic today-

Form verification

vue3 Form validation

Here we use async-validator. This is a plug-in for asynchronous validation of forms. It has 5k stars on github and is also widely used, such as

Ant.design, Element UI, Naive UI, etc. are all using this plug-in, and even some Nodejs back-end projects are also using this plug-in.

First install this plug-in, enter

pnpm install async-validator

here

async-validator version on the command line Yes4.1.1

1. Form code

Open the App.vue file in the project, delete the redundant file content, and enter the title

vue3 form verification, and add some initial code

<template>
    <div class="main">
        <h4 id="vue-nbsp-表单验证">vue3 表单验证</h4>

        <form>
            <div>
                <label class="label">账号</label>
                <input  type="text"  placeholder="请输入账号" class="input" />
            </div>
            <div>
                <label class="label">密码</label>
                <input  tyep="password" type="text" class="input"  placeholder="请输入密码"  />
            </div>

            <div>
                <button>保存</button>
            </div>
        </form>
    </div>
</template>
<script setup>

</script>
<style lang="css">
.main{
    text-align:center;
}
.label {
    padding-right: 10px;
    padding-left: 10px;
    display: inline-block;
    box-sizing: border-box;
    width: 100px;
    text-align: right;
}
.input {
    width: 200px;
    height: 30px;
    margin-top:10px;
}
</style>

Does it look a bit ugly? Don’t worry, let’s add some css code to simply beautify it

<template>
    <div class="main">
        <h4 id="Vue-表单验证">Vue3表单验证</h4>

        <form class="form-box">
            <div class="form-group ">
                <label class="label">账号</label>
                <input type="text" class="input" placeholder="请输入账号"  />
            </div>
            <div class="form-group">
                <label class="label">密码</label>
                <input  tyep="password" type="text"  placeholder="请输入密码" class="input" />
            </div>

            <div class="form-group">
                <button class="btn ">保存</button>
            </div>
        </form>
    </div>
</template>
<script setup>

</script>
<style scoped>
.main {
    text-align: center;
}
.btn{
    margin: 0;
    line-height: 1;
    padding: 15px;
    height: 30px;
    width: 60px;
    font-size: 14px;
    border-radius: 4px;
    color: #fff;
    background-color: #2080f0;
    white-space: nowrap;
    outline: none;
    position: relative;
    border: none;
    display: inline-flex;
    flex-wrap: nowrap;
    flex-shrink: 0;
    align-items: center;
    justify-content: center;
    user-select: none;
    text-align: center;
    cursor: pointer;
    text-decoration: none;
}
.form-box{
    width: 500px;
    max-width: 100%;
    margin: 0 auto;
    padding: 10px;
}
.form-group{
    margin: 10px;
    padding: 10px 15px 10px 0
}
.label {
    padding-right: 10px;
    padding-left: 10px;
    display: inline-block;
    box-sizing: border-box;
    width: 110px;
    text-align: right;
}

.input {
    width: calc(100% - 120px);
    height: 28px;
}
</style>

2. Add verification

2-1. Initialization

introduces

ref attributes and async-validator, here we add v-model binding to each input box Defined attributes,

// html
<input type="text" v-model="form.account" class="input" placeholder="请输入账号"  />
<input  tyep="password" v-model="form.password" type="text"  placeholder="请输入密码" class="input" />
// script
import { ref } from "vue"
import Schema from &#39;async-validator&#39;;

const form = ref({
    account: null,
    password: null,
})

According to the situation of the form, we define an object, which stores the objects that need to be verified and the information when the verification fails

const rules = {
    account: { required: true, message: '请输入账号' },
    password: { required: true, message: '请输入密码' }
}

Instantiate the Schema, and rules Pass in Schema and get a validator

const validator = new Schema(rules)

To verify a single form we use

lost focus event, define a function, and add this function to the out of focus event on the account input

// html
<input v-model="account" type="text" class="input" @blur="handleBlurAccount" placeholder="请输入账号"  />
// script
const handleBlurAccount = () => {}

Then write the instantiated validator function into handleBlurAccount

const handleBlurAccount = () => {
    validator.validate({account: form.value.account}, (errors, fields) => {
        if (errors && fields.account) {
            console.log(fields.account[0].message);
            return errors
        }
    })
}

Test in the input of account, we can see that

Please enter the account number## printed on the console # Wait for the words Similarly, we also add the following code to the password box

//html
<input v-model="form.password" tyep="password" type="text" @blur="handleBlurPassword"  placeholder="请输入密码" class="input" />
//script
const handleBlurPassword = () => {
    validator.validate({password: form.value.password}, (errors, fields) => {
        if (errors && fields.password) {
            console.log(errors, fields);
            console.log(fields.password[0].message);
            return errors
        }
    })
}

2-2. Verification of multiple forms

Of course, only a single input is verified here Yes, let’s talk about the verification of multiple forms next. Define a click event as submit, add the submit event to the button, and of course don’t forget to prevent the browser default event

const submit = (e) => {
    e.preventDefault();
    validator.validate(form.value, (errors, fields) => {
        if (errors) {
            for(let key of errors) {
                console.log(key.message);
            }
            return errors
        }
    })
}

2-3. Promise method After verifying

the above method,

async-validator

also provides the Promise method, we modify the code in the submit function as follows <div class="code" style="position:relative; padding:0px; margin:0px;"><pre class='brush:php;toolbar:false;'>validator.validate(form.value).then((value) =&gt; { // 校验通过 console.log(value); }).catch(({ errors, fields }) =&gt; { console.log(errors); return errors })</pre><div class="contentsignin">Copy after login</div></div>Click save, the same, We can see that the error message has been printed on the console, indicating that what we wrote is appropriate

2-4. Regular verification

Of course sometimes we Forms such as email addresses, phone numbers, etc. will be entered. At this time, we need to add regular rules for verification. We first add two forms and add out-of-focus events. Regular verification requires the attributes of

async-validator

pattern, we will add the regular rules that meet the requirements to rules. The code is as follows<div class="code" style="position:relative; padding:0px; margin:0px;"><pre class='brush:php;toolbar:false;'>&lt;div class=&quot;form-group &quot;&gt; &lt;label class=&quot;label&quot;&gt;电话号码&lt;/label&gt; &lt;input v-model=&quot;form.phone&quot; type=&quot;text&quot; class=&quot;input&quot; @blur=&quot;handleBlurPhone&quot; placeholder=&quot;请输入电话号码&quot; /&gt; &lt;/div&gt; &lt;div class=&quot;form-group &quot;&gt; &lt;label class=&quot;label&quot;&gt;邮箱&lt;/label&gt; &lt;input v-model=&quot;form.email&quot; type=&quot;text&quot; class=&quot;input&quot; @blur=&quot;handleBlurEmail&quot; placeholder=&quot;请输入邮箱&quot; /&gt; &lt;/div&gt; const form = ref({ account: null, email: null, password: null, }) const rules = { account: { required: true, message: &amp;#39;请输入账号&amp;#39; }, phone: { required: true, pattern: /^1\d{10}$/, message: &quot;请输入电话号码&quot; }, email: { required: true, pattern: /^([a-zA-Z0-9]+[_|_|\-|.]?)*[a-zA-Z0-9]+@([a-zA-Z0-9]+[_|_|.]?)*[a-zA-Z0-9]+\.[a-zA-Z]{2,6}$/, message: &quot;请输入邮箱&quot; }, password: { required: true, message: &amp;#39;请输入密码&amp;#39; } } const handleBlurPhone = () =&gt; { validator.validate({ phone: form.value.phone }, (errors, fields) =&gt; { if (errors &amp;&amp; fields.phone) { console.log(errors, fields); console.log(fields.phone[0].message); return errors } }) } const handleBlurEmail = () =&gt; { validator.validate({ email: form.value.email }, (errors, fields) =&gt; { if (errors &amp;&amp; fields.email) { console.log(errors, fields); console.log(fields.email[0].message); return errors } }) }</pre><div class="contentsignin">Copy after login</div></div>Of course, there is no problem with the test

2-5. Length control

If you To control the length of form input content, you can use the attributes min and max. We use the account form as an example. We add these two attributes to the account of the rules object. For example, the account is required to be at least 5 characters and at most 10 characters, as follows

account: { required: true, min:5, max:10, message: '请输入账号' }

We can also use the native attribute maxLength="10" of input to control the user's input

2-6. Multiple verification conditions

When we have multiple verifications When setting conditions, we can write the verification conditions of rules as an array. We still use the account form as an example. For example, the account requirement must be in Chinese, and the account number must be at least 5 characters and at most 10 characters. The code is as follows

account: [
    { required: true, min:5, max:10, message: '请输入账号' },
    { required: true, pattern: /[\u4e00-\u9fa5]/, message: '请输入中文账号' }
],

2-5. Custom verification

Sometimes, we will use a custom verification function to meet special verification situations. At this time, we can do this

field:{
    required: true,
    validator(rule, value, callback){
      return value === '';
    },
    message: '值不等于 "".',
}

Here, the prototype of vue3's form verification function has basically come out. Now we will improve the verification function

3.优化完善

之前的表单验证虽然已经做出了，但是校验的提示信息是在控制台，这个很不友好，用户也看不到提示，所以这里我们完善下这部分功能

首先我们在 label 边加一个 "*" 表示必填，并且添加样式,给一个红色，醒目一些

<label class="label">
    <span>账号</span>
    <span class="asterisk"> *</span>
</label>
.asterisk{
    color: #d03050;
}

我们考虑到 rules 对象中 required 属性的作用，这里使用 vue 的条件判断语句 v-if 来判断，先定义一个函数，名字就叫 getRequired，然后将 rules.account,作为参数传进去，这里要重点说明一下，如果考虑封装验证方法，这里可以不用传参，不多说，后面讲到了，我们再说，先看代码

 <span class="asterisk" v-if="getRequired(rules.account)"> *</span>
const getRequired = (condition) => {
    if(Object.prototype.toString.call(condition) === "[object Object]") {
        return condition.required
    } else if (Object.prototype.toString.call(condition) === "[object Array]") {
        let result = condition.some(item => item.required)
        return result
    }
    return false
}

因为 rules.account, 有可能是对象或者数组，这里我们加一个判断区别下，如果传递进来的是对象，我们直接将属性required返回回去，至于required属性是否存在，这里没有必要多判断。 如果传递进来的是数组，我们使用 some 函数获取下结果，然后再返回.

修改 rules.account 的 required 值为false，星号消失，这里只要有一个required 值为true，那么这个星号就显示

我们接着来添加错误信息的显示与隐藏

我们定义一个对象 modelControl，这个对象里面动态存储错误信息，

const modelControl = ref({})

接着给 account 的 input 框添加一个自定义属性 prop, 属性值是 account, 再加一个div显示错误提示信息

<div class="form-group">
    <label class="label">
        <span>账号</span>
        <span class="asterisk" v-if="getRequired(rules.account)"> *</span>
    </label>
    <input v-model="form.account" type="text" maxLength="10" class="input" prop="account" @blur="handleBlurAccount" placeholder="请输入账号" />
    <div class="input feedback" v-if="modelControl[&#39;account&#39;]">{{modelControl[&#39;account&#39;]}}</div>
</div>

.feedback{
    color: #d03050;
    font-size:14px;
    margin-top: 3px;
    text-align:left;
    margin-left:110px;
}

为了动态的显示和隐藏错误信息，我们需要修改失焦事件 和 submit 事件,在事件执行的时候，动态的将值赋予或清除，代码如下

const handleBlurAccount = (e) => {
    const prop = e.target.attributes.prop.value
    if (!prop) {
        return false
    }
    validator.validate({ account: form.value.account }, (errors, fields) => {
        if (errors && fields.account) {
            console.log(errors, fields);
            console.log(fields.account[0].message);

            modelControl.value[prop] = fields[prop][0].message
            return errors
        }
        modelControl.value[prop] = null
    })
}
validator.validate(form.value).then((value) => {
        // 校验通过
    console.log(value);
}).catch(({ errors, fields }) => {
    console.log(errors, fields);
    for(let key in fields) {
        modelControl.value[key] = fields[key][0].message
    }
    console.log(modelControl);
    return errors
})

到这里 表单的动态验证功能基本算是完成了，但是我们发现，每次错误信息的展示都会使得input框跳动，所以还得调整下样式

.form-group {
    margin: 2px;
    padding: 10px 15px 3px 0;
    height:57px;
    transition: color .3s ease;
}

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