[5.5] Support custom validation rule objects.

[taylorotwell]

This is a slightly different approach to use custom validation objects
compared to the current Validator::extend approach. With this addition,
you can define an object that implements
Illuminate\Validation\ValidationRule and then include it in your
validation rules like so: 'name' => [new ValidName].

This provides a quick way to define custom validation rules without
needing to call Validator::extend at all.

[axotion]

What kind of type it is? I mean $fail

[linzi007]

method

[ghost]

Is it possible to overwrite the validation message specified in the Rule with a custom message in the FormRequest?

[amadeann]

@skatika Yes. Here's what worked for me:

Added code like this to the withValidator method of my FormRequest:

$validator->addRules([
    'status' => function ($attribute, $value, $fail) {
        if ( $attribute < 10 ) {
            $fail(':attribute must be at least 10 for the validation to pass');
        }
    }
]);

If you're using classes instead of closures, change it to:

$validator->addRules([
    'status' => [new YourCustomRule]
]);