Make it easier to add custom validation

[nstCactus]

Description

As suggested in the PHPdoc of the Yii Model::defineRules() method:

Models should override this method instead of [[rules()]] so [[EVENT_DEFINE_RULES]] handlers can modify the class-defined rules.

[ademers]

I want to make the fromName and subject fields required, so in a custom module, I added:

Event::on(
    Submission::class,
    Submission::EVENT_DEFINE_RULES,
    function(DefineRulesEvent $event) {
        $event->rules[] = [['fromName', 'subject'], 'required'];
    }
);

However, it only works when I change public function rules() to public function defineRules(): array in Submission.php.

Discord: https://discordapp.com/channels/456442477667418113/456442884258922529/772923383573905470

[MoritzLost]

Any status update on this? Changing the method from rules to defineRules shouldn't change the behaviour and make it much easier to add custom validation.

[ademers]

Would really like to see this implemented!

[AugustMiller]

Discovered with @bencroker that this might be a breaking change, because Model::defineRules() is only available in Craft ^3.4.0…

Edit: Maybe not? Seems like we could quietly support 3.4+, as long as the method signature is compatible. The real fix might be more like adding parent::rules() to the overridden method?

[nstCactus]

@AugustMiller Wouldn't it be possible to bump the required Craft CMS version to 3.4 in composer.json for the next version?
That way, the plugin would still be compatible with old Craft CMS installs in its current version but users of Craft CMS > 3.4 would get new versions.

[brandonkelly]

Thanks @nstCactus! Just merged and released as 2.3.0.