fix: Change the visibility of validation properties for easier inheritance

[sammyskills]

Description
Currently, the Validation class declares the properties $config and $tables as private which makes them impossible to use within child classes. This PR fixes that.

Checklist:

• Securely signed commits
• [] Component(s) with PHPDoc blocks, only if necessary or adds value
• [] Unit testing, with >80% coverage
• [] User guide updated
• Conforms to style guide

[datamweb]

Hey @sammyskills,

I can understand why you want to inherit from Validation?
As you know, you can use customization/validation_rules.
Can you provide an example for better understanding?

[sammyskills]

Hi @datamweb,

Yes, before the refactor of the validation rules from PR #861, one could easily customize the rules. But since the rules have now been placed in a class of its own, devs might want to use(reuse) some of the methods in the validation class, to create custom rules (as another way to create or use rules).

Take for instance, I have an application that uses login via phone number and password. I can create a validation class in my app/Validations directory, named ValidationRules. Within this class, I can create a method: getLoginByPhoneNumberRules(), which also utilizes the getPasswordRules() method from the parent class, like so:

// app/Validation/ValidationRules.php
use CodeIgniter\Shield\Validation\ValidationRules as ShieldValidationRules;

class ValidationRules extends ShieldValidationRules
{
    public function getLoginByPhoneNumberRules(): array
    {
        return [
            'phone' => 'required|numeric',
            'password' => $this->getPasswordRules()
        ]
    }
}

With the above, the getValidationRules() method of my custom LoginController _(which of course extends shield's LoginControler can return my own custom rule: getLoginByPhoneNumberRules().

I hope you get what I mean.

[datamweb]

Thanks for the explanation,
when I reviewed the #861 I was aware that there would be no limit to customization.
Now I wanted to make sure that there was no limit.

Well, I understand with your explanation, you know that you can create and use your own methods and rules in file app/Config/Validation.php. However, this PR helps the integrity of the code to a great extent.
I think this PR is acceptable.

[sammyskills]

you know that you can create and use your own methods and rules in file app/Config/Validation.php

Yes, I know, and that is what I've been using for a while now. But the PR #861 provides yet another way to set validation rules, for devs who prefer not to use config files.

[kenjis]

I'm fine this change if someone wants to extend the class.