Set default database connection of a validator

[hafezdivandari]

I have a validator with a complex dynamically generated rules. I want to set default database connection for this validator to be used for the exists and unique rules' query. First, I've tried this:

$verifier = App::make('validation.presence');
$verifier->setConnection('sqlite');
$validator = Validator::make($request->data, $rules);
$validator->setPresenceVerifier($verifier);
$data = $validator->validate(); // always uses the default app DB connection not the specified one 'sqlite'

But is doesn't work and uses the app's default database connection instead. I sent a PR #38331 to fix this but closed, I realized that it won't work as expected if one of the rules has specified a specific connection on it self (the example below won't work with this PR).

Then, I sent another PR #38358 to add setConnection method to the Validator, It successfully works as expected:

$validator = Validator::make($request->data, [
    'state' => 'exists:states',          // uses 'sqlite.states'
    'email' => 'exists:connection.staff' // uses 'connection.staff'
]);
$validator->setConnection('sqlite');

But this PR is closed too:

If you can already set the connection name in the rule, I'm not sure we need to add this at this time.

My rules are not static to simply add connection name to each rule, any suggestion?

[hafezdivandari]

You may do this by defining a custom validator:

namespace App\Classes;

use Illuminate\Validation\Validator as BaseValidator;

class Validator extends BaseValidator
{
    /**
     * Get the Presence Verifier implementation.
     *
     * @param  string|null  $connection
     * @return \Illuminate\Validation\PresenceVerifierInterface
     *
     * @throws \RuntimeException
     */
    public function getPresenceVerifier($connection = null)
    {
        return tap(parent::getPresenceVerifier($connection), function ($verifier) {
            $verifier->setConnection('sqlite');
        });
    }
}

and use it:

$factory = App::make('validator');
$factory->resolver(function (...$args) {
    return new \App\Classes\Validator(...$args);
});
$validator = $factory->make($request->data, $rules);