This commit is contained in:
D065023
2019-12-23 10:10:03 +01:00
parent 1f01bdf202
commit e16a343ce3
3 changed files with 104 additions and 85 deletions

View File

@@ -1,82 +1,88 @@
const cds = require('@sap/cds')
module.exports = cds.service.impl (async()=>{
module.exports = cds.service.impl(async () => {
// We are mashing up three services...
const bupa = await cds.connect.to ('API_BUSINESS_PARTNER')
const admin = await cds.connect.to ('AdminService')
const db = await cds.connect.to ('db')
const bupa = await cds.connect.to('API_BUSINESS_PARTNER')
const admin = await cds.connect.to('AdminService')
const db = await cds.connect.to('db')
// Using reflected definitions from connected services/database
const { Addresses: externalAddresses } = bupa.entities // projection on external addresses
const { Books, Addresses } = db.entities // entities in local database
// Delegate ValueHelp requests to S/4 backend, fetching current user's addresses from there
admin.on ('READ', 'Addresses', (req) => {
console.log ('Delegating to S/4 bupa service...')
const UsersAddresses = SELECT.from (externalAddresses) .where ({ contact: req.user.id })
return bupa.tx(req) .run (UsersAddresses.where (req.query.SELECT.where))
admin.on('READ', 'Addresses', req => {
console.log('Delegating to S/4 bupa service...')
const UsersAddresses = SELECT.from(externalAddresses).where({
contact: req.user.id
})
return bupa.tx(req).run(UsersAddresses.where(req.query.SELECT.where))
})
// Replicate chosen addresses from S/4 when filing orders.
admin.before ('PATCH', 'Orders', async (req) => {
admin.before('PATCH', 'Orders', async req => {
const assigned = { ID: req.data.shippingAddress_ID, contact: req.user.id }
if (!assigned.ID) return //> something else
const local = db.transaction (req)
const [replica] = await local.read (Addresses) .where (assigned)
const local = db.transaction(req)
const [replica] = await local.read(Addresses).where(assigned)
if (replica) return //> already replicated
const [address] = await bupa.tx(req) .run (SELECT.from (externalAddresses) .where (assigned))
if (address) return local.create (Addresses) .entries (address)
const [address] = await bupa
.tx(req)
.run(SELECT.from(externalAddresses).where(assigned))
if (address) return local.create(Addresses).entries(address)
})
// Subscribe to S/4 event to update local replicas when sources change in S/4.
bupa.on ('BusinessPartner/Changed', async (msg) => {
bupa.on('BusinessPartner/Changed', async msg => {
console.log('>> received:', msg.data)
const BPID = msg.data.KEY[0].BUSINESSPARTNER // TODO: .KEY[0] >> revisit w/ Oliver
const BPID = msg.data.KEY[0].BUSINESSPARTNER // TODO: .KEY[0] >> revisit w/ Oliver
const { SELECT, UPDATE } = cds.ql(msg) //> convenient alternative to <srv>.transaction(req).run(SELECT...)
// fetch affected entries from local replicas
const replicas = await SELECT.from (Addresses) .where ({contact:BPID})
const replicas = await SELECT.from(Addresses).where({ contact: BPID })
if (replicas.length === 0) return //> not affected
// fetch changed data from S/4 -> might be less than local due to deletes
const changed = await SELECT.from (externalAddresses) .where ({
contact:BPID, ID: replicas.map(a => a.ID) // where in
const changed = await SELECT.from(externalAddresses).where({
contact: BPID,
ID: replicas.map(a => a.ID) // where in
})
// update local replicas with changes from S/4
const local = db.transaction (msg) //> using that variant to benefit from bulk runs
return local.run (changed.map (a => UPDATE (Addresses,a.ID) .with (a) ))
const local = db.transaction(msg) //> using that variant to benefit from bulk runs
return local.run(changed.map(a => UPDATE(Addresses, a.ID).with(a)))
})
// Validate incoming orders and reduce books' stocks.
admin.before ('CREATE', 'Orders', async (req) => {
admin.before('CREATE', 'Orders', async req => {
const { Items } = req.data
// validate input...
if (!Items || Items.length === 0)
return req.reject ('Please order at least one item.')
if (!req.data.shippingAddress_ID) return req.reject (
'Please enter a valid shipping address.',
'shippingAddress_ID'
)
return req.reject('Please order at least one item.')
if (!req.data.shippingAddress_ID)
return req.reject(
'Please enter a valid shipping address.',
'shippingAddress_ID'
)
// reduce stock on ordered books...
const all = await db.tx(req) .run (Items.map (each =>
UPDATE (Books) .where ('ID =', each.book_ID)
.and ('stock >=', each.amount)
.set ('stock -=', each.amount)
))
all.forEach ((affectedRows,i) => affectedRows > 0 || req.error (409,
`${Items[i].amount} exceeds stock for book #${Items[i].book_ID}`
))
const all = await db.tx(req).run(
Items.map(each =>
UPDATE(Books)
.where('ID =', each.book_ID)
.and('stock >=', each.amount)
.set('stock -=', each.amount)
)
)
all.forEach(
(affectedRows, i) =>
affectedRows > 0 ||
req.error(
409,
`${Items[i].amount} exceeds stock for book #${Items[i].book_ID}`
)
)
})
})
require('./utils') // ugly workaround for AppStudio