getting-started.md

Getting started

Install

composer require initphp/validation

Requires PHP 8.1+ and ext-mbstring.

The Validation object

Create a validator and give it the data to check. Any associative array works — $_POST, $_GET, a decoded JSON body, or a plain array.

use InitPHP\Validation\Validation;

$validation = new Validation($_POST);

// or set/merge data later
$validation->setData(['email' => 'a@b.com']);
$validation->mergeData(['name' => 'Ada']);

Queue rules, then validate

Every rule() call queues one or more checks. validation() runs the whole queue and returns a boolean. rule() is chainable.

$valid = $validation
    ->rule('email', 'required|mail')
    ->rule('name', 'required|alpha')
    ->validation();

A rule string is a pipe-separated list. The first field of email above is checked for required first, then mail.

Read the errors

getError() returns the messages produced by the most recent validation() call.

if (!$valid) {
    foreach ($validation->getError() as $message) {
        echo $message, "\n";
    }
}

isValid() returns the boolean result of that same run without re-running it.

The validation lifecycle

validation() does three things in order:

1. Clears the error list.
2. Runs every queued rule (skipping optional fields that have no value).
3. Empties the rule queue.

Because the queue is consumed, the natural pattern is queue → validate → read, then repeat:

$validation->rule('a', 'integer');
$validation->validation();          // checks only 'a'

$validation->rule('b', 'integer');
$validation->validation();          // checks only 'b'

Call clear() to drop any queued rules, optional flags and errors without validating.

A full example

require 'vendor/autoload.php';

use InitPHP\Validation\Validation;

$validation = new Validation([
    'username' => 'ada',
    'email'    => 'ada@example.com',
    'password' => 'sup3rsecret',
    'confirm'  => 'sup3rsecret',
    'age'      => '34',
]);

$valid = $validation
    ->rule('username', 'required|alphanum|length(3...20)')
    ->rule('email', 'required|mail')
    ->rule('password', 'required|length(8...)')
    ->rule('confirm', 'again(password)')
    ->rule('age', 'optional|integer|range(18...120)')
    ->validation();

if ($valid) {
    // persist the user
} else {
    $errors = $validation->getError();
}

Next: the rules reference.