[5.4] Allow adding dependent extensions to the Vallidator

[themsaid]

This PR contains the changes introduced in #18647

Tried to push my changes to the fork based on GitHub guide (https://github.com/blog/2247-improving-collaboration-with-forks) but for some reason all commits on the fork was deleted and the PR got closed. So sorry @rakesh-beedasy :/

[taylorotwell]

Can you try to explain what this does and why it is needed? I could not understand the original PR.

[themsaid]

@taylorotwell here's an example:

Validator::extendDependent('contains', function ($attribute, $value, $parameters, $validator) {
   // The $parameters passed from the validator below is ['*.provider'], when we imply that this
   // custom rule is dependent the validator tends to replace the asterisks with the current
   // indices as per the original attribute we're validating, so *.provider will be replaced
   // with 0.provider, now we can use array_get() to get the value of the other field.

    // So this custom rule validates that the attribute value contains the value of the other given
    // attribute.
    return str_contains($value, 
            array_get($validator->getData(), $parameters[0])
    );
});


Validator::make(
    [['email' => 'test@mail.com', 'provider' => 'mail.com']],
    ['*.email' => 'contains:*.provider']
)->validate();

[rakesh-beedasy]

namespace Illuminate\Validation;

class Validator implements ValidatorContract
{
    ....
    protected $dependentRules = [
        'RequiredWith', 'RequiredWithAll', 'RequiredWithout', 'RequiredWithoutAll',
        'RequiredIf', 'RequiredUnless', 'Confirmed', 'Same', 'Different', 'Unique',
        'Before', 'After', 'BeforeOrEqual', 'AfterOrEqual',
    ];
    ....
    /**
     * Validate a given attribute against a rule.
     *
     * @param  string  $attribute
     * @param  string  $rule
     * @return void
     */
    protected function validateAttribute($attribute, $rule)
    {
        ....
        // First we will get the correct keys for the given attribute in case the field is nested in
        // an array. Then we determine if the given rule accepts other field names as parameters.
        // If so, we will replace any asterisks found in the parameters with the correct keys.
        if (($keys = $this->getExplicitKeys($attribute)) &&
            $this->dependsOnOtherFields($rule)) {
            $parameters = $this->replaceAsterisksInParameters($parameters, $keys);
        }
        ....
    /**
     * Determine if the given rule depends on other fields.
     *
     * @param  string  $rule
     * @return bool
     */
    protected function dependsOnOtherFields($rule)
    {
        return in_array($rule, $this->dependentRules);
    }
....
}

Since $this->dependentRules is readonly $this->dependsOnOtherFields($rule) always returns false for any custom rule which contains a dependent field, hence $this->replaceAsterisksInParameters() never gets executed for custom rules.

When using "required_if" asterisk gets replaced fine since RequiredIf is present in readonly Illuminate\Validation\Validator::$dependentRules

//in some controller
$rules = ['items.*.field' => 'required_if:items.*.otherfield,value']

namespace Illuminate\Validation\Concerns;
trait ValidatesAttributes
{
    protected function validateRequiredIf($attribute, $value, $parameters)
    {
        //var_dump($attribute, $parameters[0])
        //$attribute as item.0.field, and $parameters[0] as item.0.otherfield  
        //$attribute as item.1.field, and $parameters[0] as item.0.otherfield 
        //hence item.0.field is required if item.0.otherfield and so on

When using a custom "required_if_in" which is a custom rule and array validation rules

//in some controller
$rules = ['items.*.field' => 'required_if_in:items.*.otherfield,value1,value2']
function ($attribute, $value, $parameters) {
    //var_dump($attribute, $parameters[0]);
    //$attribute as item.0.field, but $parameters[0] as item.*.otherfield  
    //$attribute as item.1.field, but $parameters[0] as item.*.otherfield 
    //item.0.field is required if in item.*.otherfield which is in fact an array of otherfield from an array of items

The idea would be as we can define custom implicit rules, it would be good if we could define custom dependent rules.

[Propaganistas]

Great to see this has made it to core.

[rawaludin]

This is useful. Just found it today. Could this added to the docs?

[chuck-wood]

Let me just say that I love this addition. It really simplified my validation. Thanks guys!