如何避免Laravel验证规则中的重复

Question

For validating form validation rules I currently stored them in User Model and use it in Register Controller, User controller in admin panel, User Controller in APIs and some other places, but currently it's very hard to maintain because each controller needs a slightly different set of rules and when I change the rules in User Model other controllers will not work anymore. So how to avoid duplication in rules and still keep the code maintainable?

Answer 1

Approach I often use is to write a HasRules trait for my models, it looks something like this:

trait HasRules
{
    public static function getValidationRules(): array
    {
        if (! property_exists(static::class, 'rules')) {
            return [];
        }

        if (func_num_args() === 0) {
            return static::$rules;
        }

        if (func_num_args() === 1 && is_string(func_get_arg(0))) {
            return array_get(static::$rules, func_get_arg(0), []);
        }

        $attributes = func_num_args() === 1 && is_array(func_get_arg(0))
            ? func_get_arg(0)
            : func_get_args();

        return array_only(static::$rules, $attributes);
    }
}

Looks messy, but what it does is allows you to retrieve your rules (from a static field if such exists) in a variety of ways. So in your model you can:

class User extends Model
{
    use HasRules;

    public static $rules = [
        'name' => ['required'],
        'age' => ['min:16']
    ];

    ...
}

Then in your validation (for example, in your FormRequest's rules() method or in your controllers when preparing rules array) you can call this getValidationRules() in variety of ways:

 $allRules = User::getValidationRules(); // if called with no parameters all rules will be returned.

 $onlySomeRules = [
     'controller_specific_field' => ['required'],
     'name' => User::getValidationRules('name'); // if called with one string parameter only rules for that attribute will be returned.
 ];

 $multipleSomeRules = User::getValidationRules('name', 'age'); // will return array of rules for specified attributes.

 // You can also call it with array as first parameter:
 $multipleSomeRules2 = User::getValidationRules(['name', 'age']);

Don't be afraid to write some code for generating your custom controller specific rules. Use array_merge and other helpers, implement your own (for example, a helper that adds 'required' value to array if it's not there or removes it etc). I strongly encourage you to use FormRequest classes to encapsulate that logic though.