将变量传递给验证器，Laravel

Question

I have created a custom validator in AppSeriveProvider.php with code:-

Validator::extend('less_than', function($attribute, $value, $parameters, $validator) {
    $max_field = $parameters[0];
    $data = $validator->getData();
    $max_value = 100;
    return $value < $max_value;
});

Validator::replacer('less_than', function($message, $attribute, $rule, $parameters) {
    return str_replace(':field', $parameters[0], $message);
});

And my controller have this piece of code

$messages = [
    'bid.required' => 'Please enter the amount',
    'bid.less_than' => 'Insufficient balance',
];
$balance = 100;
$v = Validator::make($request->all(), [
         'bid' => 'required|less_than:$balance',
     ],$messages);

if ($v->fails()) {
    return redirect('newgame')
           ->withErrors($v)
           ->withInput();
    }else {
            echo "Success"
     }

I have to send balance variable to the validator and in the validator function I have to set $max_value (which currently have 100) to the value in $balance.

After searching in directories and looking to the code I cannot understand that what are the contents of $parameters variable because its 0 index is referred in max_field, how $validator->getData() works? and how $max_value is getting its value.

Please someone explain me all this or comment the link to respective problems.And help in solving this big problem.

Answer 1

To solve this problem I used the laravel's function dd() to see what are the contents of each variable. And then changed the custom validator in AppSeriveProvider.php to

Validator::extend('less_than', function($attribute, $value, $parameters, $validator) {
            $balance = $parameters[0];          //$parameters array contain the $balance passed by validator::make()
            $data = $validator->getData();      //$data contain the $request->all()
            return $value < $balance;           //$value contain the bid set by user
});

Validator::replacer('less_than', function($message, $attribute, $rule, $parameters) {
            return str_replace(':field', $parameters[0], $message);
});

And the controller's code to

$messages = [
            'bid.required' => 'Please enter the amount',
            'bid.less_than' => 'Insufficient balance',
];
$balance = $user->balance;
$v = Validator::make($request->all(), [
            'bid' => "required|less_than:$balance",  //this balance variable acts as the parameter array for extended validator class
     ],$messages);                    

if ($v->fails()) {
            return redirect('newgame')
                        ->withErrors($v)
                        ->withInput();
}else {
            echo "Success";
}

Explanation is provided in comments in code.