Is there a library, plugin or something that makes it easier and more practical to validate fields, string and etc?
Ex: I have to get the username, and as it is a name will only accept letters (and spaces), something like:
$validateFields = new validateFields;
$userName = $validateFields->validateName($_POST['name']);
$userPass = ....
$userPhone = .....
The most awesome validation engine ever created for PHP
Translating:
The most impressive validation engine ever built for PHP
I really agree. The guys thought about everything when they made this library. This library has validation for many data types: cpf, cnh, cnpj, numeric, vowels, maximum, minimum, non-empty, etc.
If I'm not mistaken, they have a great contribution from Brazilian programmers.
Here's how to install (you need Composer):
composer require respect/validation
Here you have several examples of how to use.
I'll show you an example from the documentation itself:
use Respect\Validation\Validator as v;
$user = new stdClass;
$user->name = 'Alexandre';
$user->birthdate = '1987-07-01';
$userValidator = v::attribute('name', v::stringType()->length(1,32))
->attribute('birthdate', v::date()->age(18));
$userValidator->validate($user); // bool(true)