Service Handlers — CAP Best Practices

Primary reference: https://cap.cloud.sap/docs/node.js/core-services Event handlers: https://cap.cloud.sap/docs/node.js/events

Handler registration patterns

// Preferred: class-based handler (collocate logic, testable)
module.exports = class CatalogService extends cds.ApplicationService {
  async init() {
    const { Products } = this.entities

    this.before('CREATE', Products, this.validateProduct)
    this.on('submitOrder', this.onSubmitOrder)
    this.after('READ', Products, this.enrichProducts)

    return super.init()  // always call super.init()!
  }