Would it make sense to have a trait to implement Illuminate\Contracts\Validation\DataAwareRule for custom validation rules?

[rolfvandekrol]

I found myself implementing a rather complicated request validation where I needed multiple custom validation rules that also needed other data.

So I have several sections in my rules that look a bit like this

'foo' => [
    'required',
    new class() implements ValidationRule, DataAwareRule {
        /**
         * The data under validation.
         *
         * @var array
         */
        protected $data;

        /**
         * Set the current data under validation.
         *
         * @param  array  $data
         * @return $this
         */
        public function setData($data)
        {
            $this->data = $data;

            return $this;
        }

        public function validate(string $attribute, mixed $value, Closure $fail): void
        {
            // do some validation that uses $this->data
        }
    },
],

I was kinda surprised that Laravel didn't have a trait that i could use to keep the boilerplate of implementing DataAwareRule out of my code. In Laravel core there are three rules (File, Password and Email) that implement DataAwareRule. Those could also benefit from this trait.

Would such a trait would be a helpful addition to the framework? I would like to add it.

If so, a few questions to think about:

• What should the trait be named? I was thinking Illuminate\Validation\Concerns\HasDataAwareness
• There is also the Illuminate\Contracts\Validation\ValidatorAwareRule. Would we also want a helper trait for that? I didn't find myself needing it in my use case, but maybe others do.

With this proposed change my code would look like this

'foo' => [
    'required',
    new class() implements ValidationRule, DataAwareRule {
        use HasDataAwareness;

        public function validate(string $attribute, mixed $value, Closure $fail): void
        {
            // do some validation that uses $this->data or $this->getData()
        }
    },
],

[shaedrich]

'foo' => [
    'required',
    new class() implements ValidationRule, DataAwareRule {
        /**
         * The data under validation.
         *
         * @var array
         */
        protected $data;

        /**
         * Set the current data under validation.
         *
         * @param  array  $data
         * @return $this
         */
        public function setData($data)
        {
            $this->data = $data;

            return $this;
        }

        public function validate(string $attribute, mixed $value, Closure $fail): void
        {
            // do some validation that uses $this->data
        }
    },
],

I might be playing the devil's advocate here, but why did you even implement it as an anonymous class in the first place? 😂

[rolfvandekrol]

Fair question. I choose an anonymous class here, because I used this rule in just one request and a named rule class seemed a little overkill.

It could have been a named class. In which i also would prefer the use of a trait.