1. Introduction

Brief Explanation of the Tutorial's Goal

This tutorial aims to guide you through the process of using VeeValidate for form validation in Vue.js. VeeValidate is a Vue.js plugin that simplifies form validation, and it's a powerful tool for ensuring the accuracy and consistency of user input in your Vue.js applications.

What You Will Learn

• How to install and set up VeeValidate.
• How to apply validation rules to your Vue.js forms.
• How to display error messages and success notifications.

Prerequisites

• Basic understanding of Vue.js.
• A Vue.js project setup where VeeValidate will be implemented.

2. Step-by-Step Guide

Installing VeeValidate

First, you need to install VeeValidate. Navigate to your project directory in your terminal and run:

npm install vee-validate

Importing VeeValidate

Next, import and use VeeValidate in your main.js file as follows:

import Vue from 'vue';
import VeeValidate from 'vee-validate';

Vue.use(VeeValidate);

Applying Validation Rules

VeeValidate comes with a set of predefined rules, like required, email, min, max, etc. To apply these rules, add them as attributes to your form inputs. Here's an example:

<template>
  <form @submit.prevent="submitForm">
    <input v-model="email" v-validate="'required|email'" name="email" type="email" placeholder="Email">
    <span v-show="errors.has('email')">{{ errors.first('email') }}</span>
    <button type="submit">Submit</button>
  </form>
</template>

In the above code snippet, the v-validate directive applies the validation rules. The required rule means the field must be filled, and the email rule requires the field to be a valid email address.

The errors.has('email') function checks if there are any validation errors for the email field, and errors.first('email') returns the first error message.

3. Code Examples

Example 1: A simple form with required field validation.

<template>
  <form @submit.prevent="submitForm">
    <input v-model="name" v-validate="'required'" name="name" type="text" placeholder="Name">
    <span v-show="errors.has('name')">{{ errors.first('name') }}</span>
    <button type="submit">Submit</button>
  </form>
</template>

<script>
export default {
  data() {
    return {
      name: '',
    };
  },
  methods: {
    submitForm() {
      this.$validator.validateAll().then((isValid) => {
        if (isValid) {
          // submit form
        }
      });
    },
  },
};
</script>

In this example, the required rule is applied to the name field. The submitForm method checks if all the fields pass their validation rules before submitting the form.

4. Summary

In this tutorial, we've covered the basics of using VeeValidate for form validation in Vue.js. We've seen how to install VeeValidate, apply validation rules to form fields, and display error messages.

Next, you might want to explore more complex validation rules and how to create your own custom validation rules.

5. Practice Exercises

1. Create a form with three fields: name (required), email (required and must be a valid email), and age (required and must be a number). Display appropriate error messages for each field.

2. Create a registration form with the fields: username (required and must be unique), password (required and must be at least 8 characters), and password confirmation (required and must match the password field).

Remember, practice is key to mastering any new concept. Happy coding!