vue-form-validator

Deadly simple form validation for Vue.js. Features:

• Built in data types, including email, number, domain, url, etc.
• Customizable validation rules.
• Native support for async validation.

Usage

To use vue-form-validator, you need to install it to Vue.

import Vue from 'vue';
import VueValidator from 'vue-form-validator';
Vue.use(VueValidator);

Then you can use v-validator directive on form element:

<div id="app">
    <form class="form" v-validator="loginForm">
        <div class="field">
            <label>Username:</label>
            <input type="text" v-model="userName" required minlength="3">
        </div>
        <div class="field">
            <label>Password:</label>
            <input type="password" v-model="password" minlength="6">
        </div>
    </form>
</div>

var vm = new Vue({
    el: '#app',
    data: {
        userName: '',
        password: ''
    }
});

The value for v-validator attribute is required. You can use it to check the validability of the form. For the code above, vm.loginForm.$valid means whether the form is valid.

Validation rules

Validation rules are attributes added to input/select/textarea elements. For example, <input type="text" v-model="userName" required> means the input is required to fill.

required

The required rule indicates the form control must be filled or checked. Add required attribute to the form control without attribute value.

<input type="text" v-model="title" required>

minlength

The minlength="x" rule means the form control must be filled with at least x characters.

<input type="text" v-model="name" minlength="3">

Add validation rule

Adding custom validation rules are simple! Just call VueValidator.addRule function and provide rule name and validate function.

/*
 * the validate function has three arguments:
 * value: the value user filled
 * input: the form control element
 * param: the attribute value of using this rule
 */
VueValidator.addRule('myrule', function(value, input, param) {
    return {
        valid: false,
        msg: 'some error message'
    };
});

To use your customized rule, add the rule name as input's attribute:

<input type="text" myrule="some param" v-model="xx">

Async validation

To add an async validation rule, return a Promise in the validate function.

VueValidator.addRule('myrule', function(value, input, param) {
    return new Promise(function(resolve, reject) {
        setTimeout(function() {
            resolve({
                valid: false,
                msg: 'some error message'
            });
        }, 1000);
    });
});

If you have any async rules in a form, the $valid will be a Promise instead of a boolean value. You must wait for that Promise to check the form's validality:

this.registerForm.$valid.then(function(valid) {
    if (valid) {
        // post data to server
    } else {
        // do something else
    }
});

Todo

• Date format validation
• Documentation
• Unit testing

Contribution

Pull requests are welcome.