A simple and flexible validation plugin for vue 3.

Installation

npm install vue-jvalidate

Usage

1. Import and register plugin

// main.js
import jvalidate from 'vue-jvalidate';
app.use(jvalidate);

2. Inject into component

// MyForm.vue
const jvalidate = inject('jvalidate');

3. Call jvalidate() with field and validation objects

The return value will be a Map object with key and value pairs equal to the field name and error message of any failed validations. If everything passes, it will be an empty map.

// MyForm.vue
const errors = ref(new Map());
const fields = ref({
	name: '',
	email: '',
});
const validation = {
	name: ['required'],
	email: ['required', 'email']
}

function onSubmit() {
	const errors.value = jvalidate(fields.value, validation)

	if (errors.value.size) {
		// Do something with the errors
		return;
	}
}

Handling errors

The return value will be a Map object with key and value pairs equal to the field name and error message of any failed validations. If everything passes, it will be an empty map.

Nested objects keys will joined with a colon.

Displaying error messages in your template

// Top level error
<div v-if="errors.has('email')">
{{ errors.get('email') }}
</div>

// Nested error
<div v-if="errors.has('address:city')">
{{ errors.get('address:city') }}
</div>

Field Object

This is an object of the data you wish to validate

const fields = ref({
	name: '',
	email: '',
	message: '',
})

Validation Object

The validation object contains the validation rules for the values in the field object. It should mirror the schema of your fields. You can omit fields that don't require any validation.

The value of each field should be a array of validators.

Validators

A validator is an object with two properties:

1. rule: a function that takes a value and returns true or false
2. message: a string to return if the field fails the rule (i.e. it returns false)

Example validator

# Require 20 characters
{
	rule: (value) => value.length >= 20,
	message: 'A minimum of 20 characters is required'
}

Validator usage

const validation = {
	name: [{
		rule: (value) => value ? true : false,
		message: 'This field is required'
	}],
	email: [{
		rule: (value) => value ? true : false,
		message: 'This field is required'
	}, {
		rule: (value) => value.match(/^(.+)@(.+)$/),
		message: 'Please enter a valid email'
	}]
}

The example above will:

1. Check that name field is populated
2. Check that email field is populated
3. If email is populated, check that email field matches the regex pattern

The validation for each field will stop at the first failure.

Named Validators

Instead of an object, you can also pass a string that corresponds with the name of a pre-defined validator.

Using named validators

const validation = {
	name: ['required'],
	email: ['required', 'email']
}

The plugin contains a handful of pre-defined validators:

Pre-defined validators

required: {
	rule: (value) => value ? true : false,
	message: 'This field is required'
},
email: {
	rule: (value) => value.match(/^(.+)@(.+)$/),
	message: 'Invalid email'
},
phone: {
	rule: (value) => value.match(/^\(\d{3}\)\s\d{3}-\d{4}$/),
	message: 'Invalid phone number'
},
zipCode: {
	rule: (value) => value.match(/^\d{5}$/),
	message: 'Invalid zip code'
}

Adding your own named validators

You can merge your own list of validators with the pre-packaged ones in the options object when registering the plugin.

// main.js
import { myValidators } from '@/helpers/validators';
import { jvalidate } from 'vue-jvalidate';
app.use(jvalidate, { validators: myValidators });