daggerheart/module/data/chat-message/damageRoll.mjs

export default class DHDamageRoll extends foundry.abstract.TypeDataModel {
    static defineSchema() {
        const fields = foundry.data.fields;

        return {
            messageType: new fields.StringField({ initial: 'damage' }),
            title: new fields.StringField(),
            roll: new fields.DataField({}),
            targets: new fields.ArrayField(
                new fields.SchemaField({
                    id: new fields.StringField({ required: true }),
                    actorId: new fields.StringField({}),
                    name: new fields.StringField(),
                    img: new fields.StringField(),
                    hit: new fields.BooleanField({ initial: false }),
                    saved: new fields.SchemaField({
                        result: new fields.NumberField(),
                        success: new fields.BooleanField({ nullable: true, initial: null })
                    })
                })
            ),
            targetSelection: new fields.BooleanField({ initial: true }),
            hasSave: new fields.BooleanField({ initial: false }),
            isHealing: new fields.BooleanField({ initial: false }),
            onSave: new fields.StringField(),
            source: new fields.SchemaField({
                actor: new fields.StringField(),
                item: new fields.StringField(),
                action: new fields.StringField(),
                message: new fields.StringField()
            }),
            directDamage: new fields.BooleanField({ initial: true })
        };
    }

    get messageTemplate() {
        return `systems/daggerheart/templates/ui/chat/${this.messageType}-roll.hbs`;
    }

    prepareDerivedData() {
        this.hasHitTarget = this.targets.filter(t => t.hit === true).length > 0;
        this.currentTargets =
            this.targetSelection !== true
                ? Array.from(game.user.targets).map(t =>
                      game.system.api.fields.ActionFields.TargetField.formatTarget(t)
                  )
                : this.targets;
    }
}