Files
cloud-cap-samples/bookstore/srv/mashup.js
Vladislav Leonkev 737e766d53 Deploy on BTP (#793)
minimal changes required to deploy the CAP samples in _shared db_ mode:
- db: all bookshop, orders, reviews CDS models into one db instance (_shared-db_)
- services: bookstore, orders, reviews
- approuter with UI symlinks:
  - Vue: bookshop, reviews
  - Fiori: orders
 - authentification: xsuaa
 - messaging: Event Mesh
 - destinations: orders, reviews
- cds:
  - projection OrdersNoDraft for backend direct access
  - event OrderChanged
- deployment: mta.yml
2025-03-20 09:36:16 +01:00

59 lines
2.3 KiB
JavaScript

////////////////////////////////////////////////////////////////////////////
//
// Mashing up bookshop services with required services...
//
module.exports = async()=>{ // called by server.js
const cds = require('@sap/cds')
const CatalogService = await cds.connect.to ('CatalogService')
const ReviewsService = await cds.connect.to ('ReviewsService')
const OrdersService = await cds.connect.to ('OrdersService')
const db = await cds.connect.to ('db')
// reflect entity definitions used below...
const { Books } = db.entities ('sap.capire.bookshop')
//
// Delegate requests to read reviews to the ReviewsService
// Note: prepend is neccessary to intercept generic default handler
//
CatalogService.prepend (srv => srv.on ('READ', 'Books/reviews', (req) => {
console.debug ('> delegating request to ReviewsService') // eslint-disable-line no-console
const [id] = req.params, { columns, limit } = req.query.SELECT
return ReviewsService.read ('Reviews',columns).limit(limit).where({subject:String(id)})
}))
//
// Create an order with the OrdersService when CatalogService signals a new order
//
CatalogService.on ('OrderedBook', async (msg) => {
const { book, quantity, buyer } = msg.data
const { title, price } = await db.read (Books, book, b => { b.title, b.price })
return OrdersService.create ('OrdersNoDraft').entries({
OrderNo: 'Order at '+ (new Date).toLocaleString(),
Items: [{ product:{ID:`${book}`}, title, price, quantity }],
buyer, createdBy: buyer
})
})
//
// Update Books' average ratings when ReviewsService signals updated reviews
//
ReviewsService.on ('reviewed', (msg) => {
console.debug ('> received:', msg.event, msg.data) // eslint-disable-line no-console
const { subject, count, rating } = msg.data
return UPDATE(Books,subject).with({ numberOfReviews:count, rating })
})
//
// Reduce stock of ordered books for orders are created from Orders admin UI
//
OrdersService.on ('OrderChanged', (msg) => {
console.debug ('> received:', msg.event, msg.data) // eslint-disable-line no-console
const { product, deltaQuantity } = msg.data
return UPDATE (Books) .where ('ID =', product)
.and ('stock >=', deltaQuantity)
.set ('stock -=', deltaQuantity)
})
}