php 40 lines · 6 steps

How a custom phone validation rule works in Laravel

A Laravel ValidationRule wraps libphonenumber to parse and validate phone numbers against a default region.

Explained by highlit
Laravel Intermediate validation custom-rules dependency error-handling internationalization
1<?php
2 
3namespace App\Rules;
4 
5use Closure;
6use Illuminate\Contracts\Validation\ValidationRule;
7use libphonenumber\NumberParseException;
8use libphonenumber\PhoneNumberUtil;
9 
10class ValidPhoneNumber implements ValidationRule
11{
12 public function __construct(
13 private readonly ?string $defaultRegion = 'US',
14 ) {
15 }
16 
17 public function validate(string $attribute, mixed $value, Closure $fail): void
18 {
19 if (! is_string($value) || trim($value) === '') {
20 $fail('The :attribute must be a valid phone number.')->translate();
21 
22 return;
23 }
24 
25 $util = PhoneNumberUtil::getInstance();
26 
27 try {
28 $number = $util->parse($value, $this->defaultRegion);
29 } catch (NumberParseException) {
30 $fail('The :attribute is not a recognizable phone number.')->translate();
31 
32 return;
33 }
34 
35 if (! $util->isValidNumber($number)) {
36 $fail('The :attribute is not a valid phone number for the :region region.')
37 ->translate(['region' => $this->defaultRegion]);
38 }
39 }
40}
01 / 01
STEP 01

Walkthrough

Space play ←→ step click any line
Three takeaways
  1. 1Implementing ValidationRule lets you encapsulate complex domain checks as a reusable, injectable object.
  2. 2Calling $fail and returning early keeps each failure path isolated and prevents downstream code from running on bad input.
  3. 3Delegating phone parsing to libphonenumber gives you region-aware correctness instead of fragile regex guesses.

Related explainers

php 
<?php
 
class NameParser
{

Parsing a full name into components in PHP

string-parsing arrays normalization
Intermediate 8 steps
rust 
use serde::Deserialize;
 
#[derive(Debug, Deserialize)]
#[serde(untagged)]

Parsing flexible JSON shapes with serde

deserialization enums json
Intermediate 6 steps
ruby 
require "shellwords"
require "open3"
 
module Backup

Building safe shell commands in Ruby

shell-out subprocess command-injection
Intermediate 7 steps
php 
<?php
 
namespace App\Services\Checkout;
 

Validating coupons with Laravel's Pipeline

pipeline chain of responsibility transactions
Intermediate 7 steps
php 
<?php
 
namespace App\Services;
 

How a password strength validator works in PHP

validation regular-expressions data-driven
Intermediate 8 steps
php 
<?php
 
namespace App\Services;
 

Building a cached daily leaderboard in Laravel

caching aggregation eager-loading
Intermediate 9 steps

Share this explainer

Here's the card — post it anywhere.

How a custom phone validation rule works in Laravel — share card
Made with highlit — turn any snippet into a walkthrough like this in about a minute.
Explain your code