Pluggable "Benefits" API

[AugustMiller]

This is likely a separate feature from Grants—and maybe best suited for a different plugin, entirely.

The notion of "Benefits" here is something that is made available either for the duration of a subscription (perhaps a Grant, in the case of the existing plugin), or an artifact created as part of the renewal process.

Could make #1 a pluggable (or even CP-managed) thing—especially with Craft 4's new Condition Builder coming down the pipeline!

Examples

Grant

A new class Grant implements BenefitInterface or class Grant extends Benefit (TBD) might be registered and have its own handlers for Subscription events (Create, Renew, Expire, etc.)

// Unsure about `implements`, here, or what kind of interfaces we'd have to provide!
class Grant extends Benefit implements TemporalGate
{
    public function events()
    {
        return [
            // Grant a group...
            self::EVENT_ON_SUBSCRIPTION_START => [$this, 'onSubscriptionStart'],
            // ...or revoke it:
            self::EVENT_ON_SUBSCRIPTION_END => [$this, 'onSubscriptionEnd'],
        ];
    }

    // ...
}

Coupon

Monthly one-time-use Commerce coupon (i.e. for a snack service), emitted from the renewal lifecycle.

class Grant extends Benefit implements RecurringArtifact
{
    public function events()
    {
        return [
            // Create a coupon record with a unique code (or no code, and let it be automatically consumed with their Order):
            self::EVENT_ON_SUBSCRIPTION_RENEW => [$this, 'onSubscriptionRenew'],
        ];
    }

    // ...
}

Daily Digest

A frequent CRON task/clock could trigger things at a given "while subscribed" tick/interval? Say, "every n days at `time," send an email, sync the User's content with an external service, etc.

class Grant extends Benefit implements ScheduledService
{
    public function events()
    {
        return [
            // “Ticks” every [[DateInterval expression]]? Not a Stripe concept. Emit a job, or otherwise collect content at that moment to deliver:
            self::EVENT_ON_SUBSCRIPTION_TICK => [$this, 'onSubscriptionTick'],
        ];
    }

    // ...
}