Laravel 5 Validation unique pass variable placeholder

Question

Is it possible to pass the unique validation method extra where clauses with a variable?

Heres an example:

In my model I have my validation rules.

Answer 1

Defined my own class, so the existing rules declared in the class can stay.

protected $rules = array(
    "id" => 'unique_custom:data_groups,id,id=GroupId'
);

Then added a magic method for Laravel:

public function getGroupIdAttribute() {
    return $this->id;
}

In the service provider boot method:

    \Illuminate\Support\Facades\Validator::extend('unique_custom', '\Module\UniqueDataValidator@validate');

Then added the class to src folder for package:

             'The :attribute field must be unique',
                );


                /**
                 * Validate the uniqueness of an attribute value on a given database table.
                 *
                 * If a database column is not specified, the attribute will be used.
                 *
                 * @param  string  $attribute
                 * @param  mixed   $value
                 * @param  array   $parameters
                 * @return bool
                 */
                public function validate($attribute, $value, $parameters, $validator)
                {

                    $this->requireParameterCount(3, $parameters, 'unique_custom');

                    list($connection, $table) = $this->parseTable($parameters[0]);
                    $input    = $validator->getData(); // All attributes

                    $column = $this->getQueryColumn($parameters, $attribute);

                    $param1 = explode("=", $parameters[1]);
                    $value = $input[$param1[0]]; // Set value to attribute value

                    $exclude = [];
                    if (isset($parameters[2])) {
                        $exclude_values = explode("=", $parameters[2]);
                        $exclude_value = @$input[$exclude_values[0]];

                        if (!is_null($exclude_value)) {
                            $exclude_id = $exclude_values[0];
                            $exclude_value = $input[$exclude_values[0]];

                            if (!is_null($exclude_value)) {
                                $exclude[$exclude_values[0]] = $exclude_value;
                            }
                        }
                    }

                    $query = DB::table("$table")->where($column, '=', $value);

                    foreach ($exclude as $key => $value) {
                        $query->where(function ($query) use ($key, $value) {
                                $query->where($key, '!=', $value);
                        });
                    }

                    $validator->setCustomMessages($this->custom_messages);

                    return $query->count() == 0;

                }


            }

I did try and simply append my method to the existing unique method, but as they are in different class spaces, it was causing issues with Laravel's native methods:

use ValidatesAttributes;
$this->validateUnique($attribute, $value, $parameters);