A Vue validator inspired by Laravel's Validator API

A simple input validator designed to be a mixin for Vue components. Simply register the variables and rules with the validator and you get automatic error detection. Supply the validator with an array of error messages and those can be easily injected into the DOM as feedback for the user.

Installation

Grab it on npm with an npm install --save laravel-like-vue-validator

Grab it in src/Validator.js and drop it wherever you keep your mixins.

Usage

Registering Variables

Firstly, tell the validator which variables should be watched. You have a few options here:

this.name = 'validator'

this.location.zip = '07720'

this.users = [
	{ name: 'Bob', email: '[email protected]' },
	{ name: 'Wendy', email: '[email protected]' }
]


this.registerErrorChecking('name', 'required', 'Enter a name');
this.registerErrorChecking('location.zip', 'required|size:5', ['Enter a zip', 'Invalid zip'])
this.registerErrorChecking('users.*.email', 'email', 'Invalid email')

Much like Laravel, you declare the rules you want the inputs to follow as pipe delimited strings. Comma-separated arguments are added after a colon in the rule string.

rules = {
	'required': 	'The input must not be empty',
	'boolean': 		'The input must be a boolean',
	'string': 		'The input must be a string',
	'number': 		'The input must be a number',
	'array': 		'The input must be an array (object)',
	'alpha_num': 	'The input must be an alphanumeric string',
	'email': 		'The input must be a valid email'
	'regex': 		'The input must match a given regular expression',
	'max': 			'The input must be less than or equal to a given value in value or length',
	'min': 			'The input must be greater than or equal to a given value in value or length',
	'size': 		'The input must be exactly a given value in value or length',
	'equals': 		'The input must be equal to a given value',
	'in': 			'The input must be equal to one of the given arguments',
}

examples = [
	'required|alpha_num',
	'email',
	'required|in:yes,no,maybe',
	'string|regex:^[0-9]{1,2}$',
]

The regex rule currently does NOT support pipes within your expression argument. This is due to the fact that the rules string is parsed according to pipe delimiters.

Any arguments that return something truthy from parseFloat(arg) are saved as numbers and not strings.

Error checking

Automatic

By default, whenever Vue detects a change, the validator will automatically re-run error checking on that variable. You can switch to manual error checking with an optional fourth argument.

this.me = 'Dan'
this.you = 'github'

this.registerErrorChecking('me', 'required', 'Enter something')
this.registerErrorChecking('you', 'required', 'Enter something', false)

this.me = ''
this.you = ''

console.log(this.errors.me) 	// 'Enter something'
console.log(this.errors.you) 	// ''

Manual

The errorCheck() function returns the number of detected errors. There are quite a few ways to use the errorCheck() function, but it all comes down to your desired scope.

Check all registered variables

this.name = ''
this.email = 'cats';

this.registerErrorChecking('name', 'required', 'Enter a name')
this.registerErrorChecking('email', 'email', 'Invalid email')

var errors = this.errorCheck() 

console.log(errors)				// 2
console.log(this.errors.name) 	// 'Enter a name' 	
console.log(this.errors.email) 	// 'Invalid email' 	

Check only a specific variable

this.name = ''
this.email = 'cats';

this.registerErrorChecking('name', 'required', 'Enter a name')
this.registerErrorChecking('email', 'email', 'Invalid email')

var errors = this.errorCheck('name')

console.log(errors)				// 1
console.log(this.errors.name) 	// 'Enter a name' 	
console.log(this.errors.email) 	// '' 	

Check a specific key on a variable

this.location = { 
	city: { 
		name: 'Bradley Beach, NJ',
		zip: '984'
	}
}

this.registerErrorChecking('location.city.name', 'required', 'Enter your city')
this.registerErrorChecking('location.city.zip', 'required|size:5', ['Enter a zip', 'Invalid zip'])

var errors = this.errorCheck('location.city.zip') 

console.log(errors)								// 1
console.log(this.errors.location.city.name) 	// '' 	
console.log(this.errors.location.city.zip) 		// 'Invalid zip' 	

Check a specific index in an array

this.users = [ 
	{ 
		name: 'Bob Example',
		email: 'bob@'
	},
	{ 
		name: 'Wendy Example',
		email: 'wendy@example'
	},
]


this.registerErrorChecking('users.*.email', 'required|email', 'Invalid email')

var errors = this.errorCheck('users.1.email') 

console.log(errors)							// 1
console.log(this.errors.users[0].email) 	// '' 	
console.log(this.errors.users[1].email) 	// 'Invalid email' 	

Manually assigned error messages

For the people who want to manually control a message in this.errors, but want their error checking declarations to look consistent

this.name = {
	first: '',
	last: '',
}

this.manualErrorChecking('name.first');
this.manualErrorChecking('name.last', 'Invalid lastname'); // optional default

console.log(this.errors.name.first) // ''
console.log(this.errors.name.first) // 'Invalid lastname'

Applications

Displaying in the DOM

Since Vue is reactive, you can very easily attach error messages near inputs.

<div>
	<input type="text" v-model="name">
	<span class="form-error">{{ errors.name }}</span>
</div>

Checking before Submitting

Simply place the following code into your submit() method and you are sure to have valid inputs!

/**
 * Make POST request
 */
submit() 
{
	if (this.errorCheck() > 0) {
		return
	}

	//
}

Putting it all together

import Vue from 'vue'
import Validator from 'laravel-like-vue-validator'

const vm = new Vue({
	template: '<div></div>',
	mixins: [ Validator ],
	
	data: function()
	{
		return [
			users: [
				{ name: 'Bob', email: '[email protected]' },
				{ name: 'Wendy', email: 'bob@example' }, 	// note the error
			],
			
			location: {
				city: {
					name: 'Bradley Beach',
					zip: '070' 				// ouch, another one
				}
			}
		];
	},
	
	created: function()
	{
		this.registerErrorChecking('users.*.name', 'required|max:50', ['Enter a name', 'Quit lying'])
		this.registerErrorChecking('users.*.email', 'required|email', 'Bad email')
		
		this.registerErrorChecking('location.city.zip', 'required|size:5|number', 'Invalid zip')
		this.registerErrorChecking('location.city.name', 'required|string', 'Enter your city')
	},
	
	ready: function()
	{
		var errors = this.errorCheck();
		
		console.log(errors) // 2
		
		console.log(this.errors[1].email) 			// 'Bad email'
		console.log(this.errors.location.city.zip) 	// 'Invalid zip'
		
	}
})

Testing

The repo comes prepared for a karma-jasmine test suite. Run npm run test-build in the repo root followed by karma start.