[11.x] Add fluent RegExp validation class rule

[shaedrich]

Similar to #54488, #53465, #54425, #54517, and #54519

Examples

Simplest case

use Illuminate\Validation\Rule;

public function rules()
{
    return [
        'foo' => [
            'required',
            Rule::regex('/[a-z]/'), // results in 'regex:/[a-z]/'
        ],
    ];
}

Negation

use Illuminate\Validation\Rule;

public function rules()
{
    return [
        'foo' => [
            'required',
            Rule::regex('/[a-z]/')->not(), // results in 'not_regex:/[a-z]/'
        ],
    ];
}

Flags

use Illuminate\Validation\Rule;

public function rules()
{
    return [
        'foo' => [
            'required',
            Rule::regex('/[a-z]/i'), // results in 'regex:/[a-z]/i'
            // or Rule::regex('/[a-z]/', ['i'])
            // or Rule::regex('/[a-z]/')->flags(['i'])
        ],
    ];
}

Modify flags

use Illuminate\Validation\Rule;

public function rules()
{
    $rule = Rule::regex('/[a-z]/i');
    $rule->flag('g');
    return [
        'foo' => [
            'required',
            $rule, // results in 'regex:/[a-z]/gi'
        ],
    ];
}

[AndrewMast]

I like this suggestion! I have a few comments that I feel like will help it be inline with the usual Laravel code that I will add in a review/comments.

[shaedrich]

@AndrewMast Sure, feedback is always welcome 👍🏻

[AndrewMast]

What if we get all of the flags from the expression when we create the instance? This way if we call ->flags('i', 'g', ...) (which current replaces all flags with the flags provided), it will not keep any of the flags originally in the expression. Then we can just add implode('', $this->flags) to the ->append(...) here.

[AndrewMast]

Maybe we could do something like this for the constructor:

public function __construct(string $expression, array|Arrayable $extraFlags = [])
{
    $currentFlags = str_split(Str::of($expression)->afterLast('/'));

    if ($extraFlags instanceof Arrayable) {
        $extraFlags = $extraFlags->toArray();
    }
    
    $this->expression = Str::of($expression)->beforeLast('/')->append('/')->toString();
    $this->flags = array_unique([...$currentFlags, ...$extraFlags]);
}

[shaedrich]

which current replaces all flags with the flags provided

That was the idea. The class has essentially two methods for this:

• setFlags(): Entirely replaces the flags (named flags() due to naming conventions)
• addFlag(): Adds a flag to the list of flags without replacing them (named flag() due to naming conventions

[AndrewMast]

That's what I assumed! Now with the updated constructor code, it makes much more sense to me. Good work!

[shaedrich]

Good work!

Primarily due to your feedback 👍🏻 Thanks a lot!

[taylorotwell]

Thanks for your pull request to Laravel!

Unfortunately, I'm going to delay merging this code for now. To preserve our ability to adequately maintain the framework, we need to be very careful regarding the amount of code we include.

If applicable, please consider releasing your code as a package so that the community can still take advantage of your contributions!