From 902afd8a760e4ea6b88fd57b40fafa706b2de705 Mon Sep 17 00:00:00 2001
From: Uwe Klinger <uwe.klinger@sap.com>
Date: Wed, 5 May 2021 11:36:36 +0200
Subject: [PATCH] Change event to reflect the real event definition

---
 README.md                                     | 24 ++++++++++++++---
 .../srv/external/API_BUSINESS_PARTNER.js      |  4 +--
 suppliers/srv/mashup.cds                      |  6 ++---
 suppliers/srv/mashup.js                       | 26 ++++++++-----------
 4 files changed, 37 insertions(+), 23 deletions(-)

diff --git a/README.md b/README.md
index dce6bb91..42461ee1 100644
--- a/README.md
+++ b/README.md
@@ -95,7 +95,25 @@ Copyright (c) 2021 SAP SE or an SAP affiliate company. All rights reserved. This
 
 ## Usage
 
-1. Run: `PORT=5001 cds mock API_BUSINESS_PARTNER`
+1. Run:
+
+   ```
+   cds mock API_BUSINESS_PARTNER -p 5001
+   ```
+
 2. Wait until startup is completed
-3. Run in a 2nd terminal: `cds serve all --with-mocks --in-memory`
-4. Now, you can issues the requests listed in `suppliers/requests.http`
\ No newline at end of file
+3. Run in a 2nd terminal:
+
+   ```
+   cds serve all --with-mocks --in-memory
+   ```
+
+4. Now, you can issues the requests listed in `suppliers/requests.http`
+
+## Request Sequence
+
+* TODO
+## URLs
+
+* Get books with their replicated supplier: http://localhost:4004/browse/Books?$expand=supplier
+* Get remote suppliers: http://localhost:4004/admin/Suppliers?$top=11
\ No newline at end of file
diff --git a/suppliers/srv/external/API_BUSINESS_PARTNER.js b/suppliers/srv/external/API_BUSINESS_PARTNER.js
index b879e841..d770c612 100644
--- a/suppliers/srv/external/API_BUSINESS_PARTNER.js
+++ b/suppliers/srv/external/API_BUSINESS_PARTNER.js
@@ -3,9 +3,9 @@ const cds = require('@sap/cds');
 module.exports = cds.service.impl(function () {
   const { A_BusinessPartner } = this.entities;
 
-  // TODO: Take over the original S/4 event definition
+  // https://api.sap.com/event/SAPS4HANACloudBusinessEvents_BusinessPartner/resource
   this.after('UPDATE', A_BusinessPartner, async data => {
     console.log(`>>> BusinessPartner updated ${data.BusinessPartner}`);
-    await this.emit("A_BusinessPartner.Changed", { businessPartners: [ data.BusinessPartner ] });
+    await this.emit("BusinessPartner.Changed", { BusinessPartner: data.BusinessPartner });
   });
 });
diff --git a/suppliers/srv/mashup.cds b/suppliers/srv/mashup.cds
index d1648bc7..c0bf86fe 100644
--- a/suppliers/srv/mashup.cds
+++ b/suppliers/srv/mashup.cds
@@ -69,8 +69,8 @@ extend projection CatalogService.ListOfBooks with {
 
 // Extend S4 service with not modelled event
 extend service S4 {
-  @topic: 'BusinessPartners/Changed'
-  event A_BusinessPartner.Changed {
-    BusinessPartners: array of S4.A_BusinessPartner:BusinessPartner;
+  @topic: 'BusinessPartner/Changed'
+  event BusinessPartner.Changed {
+    BusinessPartner: S4.A_BusinessPartner:BusinessPartner;
   }
 }
\ No newline at end of file
diff --git a/suppliers/srv/mashup.js b/suppliers/srv/mashup.js
index 3b528ad3..3de8f285 100644
--- a/suppliers/srv/mashup.js
+++ b/suppliers/srv/mashup.js
@@ -38,31 +38,27 @@ module.exports = async()=>{ // called by server.js
   })
 
   // Subscribe to changes in the S4 origin of Suppliers data
-  // REVISIT: cds context is still from the UPDATE method when running in same programm, but should
-  // be a separate
-  // https://github.wdf.sap.corp/cap/matters/projects/44#card-196556
-  S4bupa.on ('A_BusinessPartner.Changed', async msg => { //> would be great if we had batch events from S/4
+  S4bupa.on ('BusinessPartner.Changed', async msg => { //> would be great if we had batch events from S/4
     await new Promise( resolve => setTimeout( resolve, 1000 ));
-    let replicas = await SELECT('ID').from (Suppliers) .where ('ID in', msg.data.businessPartners);
-    await replicate(replicas.map(each => each.ID));
+    const id = msg.data.BusinessPartner;
+    let replica = await SELECT.one('ID').from (Suppliers) .where ('ID =', id);
+    if (replica) await replicate(id);
   })
 
   /**
    * Helper function to replicate Suppliers data.
-   * @param {string|string[]} IDs a single ID or an array of IDs
+   * @param {string} a single ID
    * @param {truthy|falsy} _initial indicates whether an insert or an update is required
    */
-  async function replicate (IDs,_initial) {
-    if (!Array.isArray(IDs)) IDs = [ IDs ]
+  async function replicate (id,_initial) {
     // TODO: Doesn't work when running in same process with mocked API_BUSINESS_PARTNER
 
-    // TODO: Issue
-    let suppliers = await S4bupa.read (Suppliers).where(...([[]].concat(IDs).reduce( (where, id, index ) => { where.push(`${index>1 ? "OR ":""}ID = `, id); return where })));
-    //let suppliers = await S4bupa.read (Suppliers).where('ID in',IDs)
+    // TODO: Doesn't work because fields are not mapped back!
+    //let supplier = await S4bupa.run(SELECT.one('*').from(Suppliers).where('ID =',id));
+
+    let suppliers = await S4bupa.read(Suppliers).where('ID =',id);
     if (_initial) return db.insert (suppliers) .into (Suppliers) //> using bulk insert
-    else return Promise.all(suppliers.map ( //> parallelizing updates
-      each => db.update (Suppliers,each.ID) .with (each)
-    ))
+    else return db.update(Suppliers,id) .with (suppliers[0]);
   }