revised

packages/bookshop/app/common.cds

@@ -73,12 +73,12 @@ annotate my.Authors with {
 	name @title:'{i18n>AuthorName}';
 }
 
-annotate my.ShippingAddresses with {
+annotate my.Addresses with {
-	AddressID @title:'{i18n>AddressID}';
+	ID @title:'{i18n>AddressID}';
 	BusinessPartner @title:'{i18n>BusinessPartner}';
-	cityName @title:'{i18n>cityName}' @readonly;
+	@readonly cityName @title:'{i18n>cityName}';
-	streetName @title:'{i18n>streetName}' @readonly;
+	@readonly streetName @title:'{i18n>streetName}';
-	postalCode @title:'{i18n>postalCode}' @readonly;
+	@readonly postalCode @title:'{i18n>postalCode}';
-	country @title:'{i18n>country}' @readonly;
+	@readonly country @title:'{i18n>country}';
-	houseNumber @title:'{i18n>houseNumber}' @readonly;
+	@readonly houseNumber @title:'{i18n>houseNumber}';
 }

packages/bookshop/app/orders/fiori-service.cds

@@ -29,8 +29,8 @@ annotate AdminService.Orders with {
             Parameters      : [
                 {
                     $Type             : 'Common.ValueListParameterOut',
-                    LocalDataProperty : 'shippingAddress_AddressID',
+                    LocalDataProperty : 'shippingAddress_ID',
-                    ValueListProperty : 'AddressID'
+                    ValueListProperty : 'ID'
                 },
                 {
                     $Type             : 'Common.ValueListParameterOut',
@@ -110,7 +110,7 @@ annotate AdminService.Orders with @(UI : {
         },
         {Value    : OrderNo},
         {
-            Value : 'shippingAddress',
+            Value : 'shippingAddress_ID',
             Label : 'Address ID'
         }
     ],
@@ -157,7 +157,7 @@ annotate AdminService.Orders with @(UI : {
     ]},
     FieldGroup #ShippingAddress : {Data : [
         {
-            Value : shippingAddress_AddressID,
+            Value : shippingAddress_ID,
             Label : '{i18n>shippingAddress}'
         },
         {
@@ -180,7 +180,7 @@ annotate AdminService.Orders with @(UI : {
 },
 Common.SideEffects : {
         EffectTypes      : #ValueChange,
-        SourceProperties : [shippingAddress_AddressID],
+        SourceProperties : [shippingAddress_ID],
         TargetProperties : [
             shippingAddress.country,
             shippingAddress.houseNumber,

packages/bookshop/db/schema.cds

@@ -1,6 +1,5 @@
 namespace sap.capire.bookshop;
 using { Currency, managed, cuid } from '@sap/cds/common';
-using { API_BUSINESS_PARTNER as external } from '../srv/external/API_BUSINESS_PARTNER';
 
 entity Books : managed {
   key ID : Integer;
@@ -8,7 +7,7 @@ entity Books : managed {
   descr  : localized String(1111);
   author : Association to Authors;
   stock  : Integer;
-  price  : Decimal(9,2);
+  price  : Decimal;
   currency : Currency;
 }
 
@@ -25,24 +24,12 @@ entity Authors : managed {
 entity Orders : cuid, managed {
   OrderNo  : String @title:'Order Number'; //> readable key
   Items    : Composition of many OrderItems on Items.parent = $self;
-  total    : Decimal(9,2) @readonly;
+  total    : Decimal @readonly;
   currency : Currency;
-  shippingAddress : Association to one ShippingAddresses;
 }
 entity OrderItems : cuid {
   parent    : Association to Orders;
   book      : Association to Books;
   amount    : Integer;
-  netAmount : Decimal(9,2);
+  netAmount : Decimal;
-}
-
-@cds.persistence: {table, skip: false}
-entity ShippingAddresses as projection on external.A_BusinessPartnerAddress  {
-  key AddressID,
-  key BusinessPartner,
-  Country as country,
-  CityName as cityName,
-  PostalCode as postalCode,
-  StreetName as streetName,
-  HouseNumber as houseNumber
 }

packages/bookshop/package.json

@@ -18,26 +18,12 @@
       "API_BUSINESS_PARTNER": {
         "kind": "odata",
         "model": "srv/external/API_BUSINESS_PARTNER",
-        "credentials": {
+        "--credentials": { ">>": "should go to bindings !!!",
           "destination": "cap-api532",
           "prefix": "sap/S4HANAOD/c532/BO"
         }
-      },
-      "messaging": {
-        "kind": "enterprise-messaging"
-      }
-    },
-    "auth": {
-      "passport": {
-        "strategy": "mock",
-        "users": {
-          "alice": {
-            "roles": ["admin"],
-            "password": "secret",
-            "ID": "ALICE"
-          }
-        }
       }
     }
+
   }
 }

packages/bookshop/srv/admin-service.cds

@@ -4,7 +4,6 @@ service AdminService @(requires:'admin') {
   entity Books as projection on my.Books;
   entity Authors as projection on my.Authors;
   entity Orders as select from my.Orders;
-  entity Addresses as projection on my.ShippingAddresses;
 }
 
 // Enable Fiori Draft for Orders

packages/bookshop/srv/admin-service.js

@@ -1,131 +1,98 @@
 const cds = require('@sap/cds')
-const { Books, ShippingAddresses } = cds.entities
 
-const bupaSrv = cds.connect.to('API_BUSINESS_PARTNER')
+// We are mashing up three services...
+const admin = cds.connect.to ('AdminService')
+const bupa = cds.connect.to('API_BUSINESS_PARTNER')
+const db = cds.connect.to('db')
 
-const _diff = (obj1, obj2) =>
+// Reflected entities for local database
-  Object.keys(obj1).reduce(
+const { Books, Addresses } = db.entities
-    (res, curr) =>
+
-      obj1[curr] === obj2[curr] ? res : (res[curr] = obj2[curr]) && res,
+// Fetch current user's addresses from S/4 for ValueHelp.
-    {}
+module.exports = (admin => {
+  admin.on ('READ', 'usersAddresses', async (req) => {
+    // const UsersAddresses = req.query.from (Addresses) .where ({ BusinessPartner: req.user.id })
+    // FIXME: Again that absolutely useless error message:
+    // [2019-12-16T20:30:14.106Z | ERROR | 1940862]: The server does not support the functionality required to fulfill the request
+    // FIXME: Even worse: click Orders Edit ->
+    // [2019-12-16T20:38:52.918Z | WARNING | 1575675]: Not Found
+    const { A_BusinessPartnerAddress:Addresses } = bupa.entities
+    const UsersAddresses = SELECT.from (Addresses, a => {
+      a.AddressID.as('ID'),
+      a.BusinessPartner,
+      a.Country.as('country'),
+      a.CityName.as('cityName'),
+      a.PostalCode.as('postalCode'),
+      a.StreetName.as('streetName'),
+      a.HouseNumber.as('houseNumber')
+    }) .where ({ BusinessPartner: req.user.id })
+    return bupa.transaction(req) .run (UsersAddresses) // TODO: I'd like to write .read instead of .run
+  })
+})
+
+// Replicate chosen addresses from S/4 when filing orders.
+admin.before ('PATCH', 'Orders', async (req) => {
+  const ID = req.data.shippingAddress_ID; if (!ID) return //> something else
+  const address = await bupa.tx(req) .run (
+    SELECT.one.from(Addresses).where({
+      ID, BusinessPartner: req.user.id
+    })
+  )
+  if (address) return db.tx(req) .upsert (Addresses) .entries (address)
+})
+
+// Update local replicas when sources change in S/4.
+bupa.on ('BusinessPartner/Changed', async (msg) => {
+  console.log('>> received:', msg.data)
+
+  const BusinessPartner = msg.data.KEY[0].BUSINESSPARTNER //> .KEY[0] >> revisit w/ Oliver
+
+  // fetch affected entries from local replicas
+  const local = db.transaction (msg)
+  const replicas = await local.read (Addresses) .where ({BusinessPartner})
+
+  // skip if not affected
+  if (replicas.length === 0) return
+
+  // fetch changed data from S/4 -> might be less than local due to deletes
+  const changed = await bupa.tx(msg).read (Addresses) .where ({
+    BusinessPartner, ID: replicas.map(a => a.ID) // where in
+  })
+
+  // update local replicas with changes from remote
+  return local.run (changed.map (a =>
+    UPDATE (Addresses) .with(a) .where ({ ID: a.ID })
+  ))
+
+})
+
+// Validate incoming orders and reduce books' stocks.
+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 shpping address.',
+    'shippingAddress_ID'
   )
 
-const _queriesToUpdateDifferences = (ownAddresses, remoteAddresses) =>
+  // reduce stock on ordered books...
-  ownAddresses
+  const all = await db.tx(req) .run (Items.map (each =>
-    .map(ownAddress => {
+    UPDATE (Books) .set ('stock -=', each.amount)
-      const remoteAddress = remoteAddresses.find(
+    .where ('ID =', each.book_ID) .and ('stock >=', each.amount)
-        address =>
+  ))
-          address.BusinessPartner === ownAddress.BusinessPartner &&
+  all.forEach ((affectedRows,i) => affectedRows > 0 || req.error (409,
-          address.AddressID === ownAddress.AddressID
+    `${Items[i].amount} exceeds stock for book #${Items[i].book_ID}`
-      )
+  ))
-      if (remoteAddress) {
-        const diff = _diff(ownAddress, remoteAddress)
-        if (Object.keys(diff).length) {
-          return UPDATE(ShippingAddresses)
-            .set(diff)
-            .where({
-              BusinessPartner: ownAddress.BusinessPartner,
-              AddressID: ownAddress.AddressID
-            })
-        }
-      }
-    })
-    .filter(el => el)
 
-bupaSrv.on('Changed', 'BusinessPartner', async msg => {
-  console.log('>> Message:', msg.data)
-
-  const BusinessPartner = msg.data.KEY[0].BUSINESSPARTNER
-  const tx = cds.transaction(msg)
-  const selectQuery = SELECT.from(ShippingAddresses).where({ BusinessPartner })
-
-  const ownAddresses = await tx.run(selectQuery)
-  if (ownAddresses && ownAddresses.length > 0) {
-    const txExt = bupaSrv.transaction(msg)
-    try {
-      const remoteAddresses = await txExt.run(selectQuery)
-      const queriesToUpdateDifferences = _queriesToUpdateDifferences(
-        ownAddresses,
-        remoteAddresses
-      )
-      await tx.run(queriesToUpdateDifferences)
-    } catch (e) {
-      console.error(e)
-    }
-  }
 })
 
-async function _readAddresses (req) {
+// eslint-disable-next-line no-unused-vars
-  console.log('Addresses', ShippingAddresses)
+function _diff (a,b) {
-  const BusinessPartner = req.user.id
+  let any, diff={}
-  const txExt = bupaSrv.transaction(req)
+  for (let each in b) if (b[each] !== a[each])  diff[each] = b[any=each]
-  const selectQuery = req.query.from(ShippingAddresses).where({ BusinessPartner })
+  return any && diff
-
-  try {
-    return txExt.run(selectQuery)
-  } catch (e) {
-    console.log(e)
-  }
 }
-
-async function _fillAddress (req) {
-  if (req.data.shippingAddress_AddressID) {
-    const BusinessPartner = req.user.id
-    const txExt = bupaSrv.transaction(req)
-    try {
-      const response = await txExt.run(
-        SELECT.from(ShippingAddresses).where({
-          AddressID: req.data.shippingAddress_AddressID,
-          BusinessPartner
-        })
-      )
-      if (response && response.length === 1) {
-        const tx = cds.transaction(req)
-        const insertQuery = INSERT.into(ShippingAddresses).entries(response)
-        await tx.run(insertQuery)
-      }
-    } catch (e) {}
-  }
-}
-
-async function _reduceStock (req) {
-  const { Items: OrderItems } = req.data
-  if (OrderItems && OrderItems.length > 0) {
-    const all = await cds.transaction(req).run(
-      OrderItems.map(order =>
-        UPDATE(Books)
-          .set('stock -=', order.amount)
-          .where('ID =', order.book_ID)
-          .and('stock >=', order.amount)
-      )
-    )
-    all.forEach((affectedRows, i) => {
-      if (affectedRows === 0)
-        req.error(
-          409,
-          `${OrderItems[i].amount} exceeds stock for book #${
-            OrderItems[i].book_ID
-          }`
-        )
-    })
-  }
-}
-
-function _checkMandatoryParams (req) {
-  if (!req.data.Items || !req.data.Items.length) {
-    return req.reject('Please order at least one item.')
-  }
-  if (!req.data.shippingAddress_AddressID) {
-    return req.reject(
-      'Please enter a valid shpping address.',
-      'shippingAddress_AddressID'
-    )
-  }
-}
-
-module.exports = cds.service.impl(function () {
-  this.before('CREATE', 'Orders', _reduceStock)
-  this.before('CREATE', 'Orders', _checkMandatoryParams)
-  this.before('PATCH', 'Orders', _fillAddress)
-  this.on('READ', 'Addresses', _readAddresses)
-})

packages/bookshop/srv/cat-service.cds

@@ -10,6 +10,5 @@ service CatalogService {
 
   @requires_: 'authenticated-user'
   @insertonly entity Orders as projection on my.Orders;
-  entity Addresses as projection on my.ShippingAddresses;
 
 }

packages/bookshop/srv/external.cds

@@ -0,0 +1,76 @@
+using { API_BUSINESS_PARTNER as external } from './external/API_BUSINESS_PARTNER.csn';
+
+/**
+ * Tailor the imported API to our needs...
+ */
+extend service API_BUSINESS_PARTNER with {
+
+  /**
+   * Simplified view on external addresses
+   */
+  entity Addresses as projection on external.A_BusinessPartnerAddress {
+    key AddressID as ID,
+    key BusinessPartner,
+    Country as country,
+    CityName as cityName,
+    PostalCode as postalCode,
+    StreetName as streetName,
+    HouseNumber as houseNumber
+  };
+
+  /**
+   * Re-modelling the event which is currently not available declaratively from S/4
+   */
+  // @messaging.topic:'sap/S4HANAOD/c532/BO/BusinessPartner/Changed'
+  // event "BusinessPartner/Changed" {
+  //   "KEY": array of {
+  //     BUSINESSPARTNER : external.A_BusinessPartner.BusinessPartner
+  //   }
+  // }
+}
+
+
+/**
+ * Mashup w/ services to also serve shipping addresses
+ */
+using { AdminService } from './admin-service';
+extend service AdminService {
+  entity usersAddresses as projection on bookshop.Addresses;
+}
+
+using { CatalogService } from './cat-service';
+extend service CatalogService {
+  @readonly @requires:'authenticated-user'
+  entity usersAddresses as projection on bookshop.Addresses;
+}
+
+
+/**
+ * Mashup w/ domain model for federated data access
+ */
+using { sap.capire.bookshop } from '../db/schema';
+
+/**
+ * Extend Orders to maintain references to (replicated) external Addresses
+ */
+extend bookshop.Orders with {
+  shippingAddress : Association to bookshop.Addresses;
+}
+
+/**
+ * Add an entity to replicate external address data for quick access,
+ * e.g. when displaying lists of orders.
+ */
+@cds.persistence:{table,skip:false}
+entity sap.capire.bookshop.Addresses as SELECT from external.Addresses { *,
+  false as tombstone : Boolean
+};
+// entity sap.capire.bookshop.Addresses as SELECT from external.A_BusinessPartnerAddress {
+//   key AddressID as ID,
+//   key BusinessPartner,
+//   Country as country,
+//   CityName as cityName,
+//   PostalCode as postalCode,
+//   StreetName as streetName,
+//   HouseNumber as houseNumber
+// };

packages/bookshop/srv/external/API_BUSINESS_PARTNER.js

@@ -5,8 +5,8 @@ module.exports = srv => {
         const payload = {
             KEY: [{ BUSINESSPARTNER: req.data.BusinessPartner }]
         }
-        console.log('<< Message:', payload)
+        console.log('<< emitting:', payload)
-        srv.emit('sap/S4HANAOD/c532/BO/BusinessPartner/Changed', payload)
+        srv.emit('BusinessPartner/Changed', payload)
 
     })