Own transaction when raising an event

README.md

@@ -84,3 +84,9 @@ In case you've a question, find a bug, or otherwise need support, use our [commu
 ## License
 
 Copyright (c) 2021 SAP SE or an SAP affiliate company. All rights reserved. This file is licensed under the Apache Software License, version 2.0 except as noted otherwise in the [LICENSE](LICENSE.txt) file.
+
+## TODOs
+
+1. Move `Suppliers` out of `API_BUSINESS_PARTNER` - remove additional lines in monkey patch --> Uwe
+2. Fix problem with `await S4bupa.read (Suppliers).where('ID in',IDs)` --> Johannes
+3.

suppliers/requests.http

@@ -1,8 +1,9 @@
 
 @server = http://localhost:4004
+@bpServer = http://localhost:59847
 @authAlice = Authorization: Basic alice:
 
-PUT {{server}}/api-business-partner/A_BusinessPartner('ACME')
+PATCH {{server}}/api-business-partner/A_BusinessPartner('ACME')
 Content-Type: application/json
 
 {

suppliers/srv/mashup.js

@@ -26,26 +26,26 @@ module.exports = async()=>{ // called by server.js
     admin.on (['CREATE','UPDATE'], 'Books', async ({data:{supplier_ID: supplierId}}, next) => {
       // Using Promise.all(...) to parallelize local write, i.e. next(), and replication
 
-      /*
+      const replicateIfNotExists = async()=>{
-      // ERROR: Reference integrity is violated for association "supplier"
-      if (supplierId) return Promise.all ([ next(), async()=>{
-        let replicated = await db.exists (Suppliers, supplierId)
-        if (!replicated) await replicate (supplierId, 'initial')
-      }])
-      else return next() //> don't forget to pass down the interceptor stack
-      */
-
         let replicated = await db.exists (Suppliers, supplierId);
         if (!replicated) await replicate (supplierId, 'initial');
-      return next();
+      };
+
+      if (supplierId) return Promise.all ([ next(), replicateIfNotExists() ])
+      else return next() //> don't forget to pass down the interceptor stack
     })
 
   })
 
   // Subscribe to changes in the S4 origin of Suppliers data
+  // REVISIT: cds context is still from the UPDAT method when running in same programm, but should
+  // be a separate
   S4bupa.on ('BusinessPartners/Changed', async msg => { //> would be great if we had batch events from S/4
-    let replicas = await SELECT('ID').from (Suppliers) .where ('ID in', msg.businessPartners)
+    await new Promise( resolve => setTimeout( resolve, 1000 ));
-    return replicate (replicas.map(each => each.ID))
+    const tx = cds.db.tx(msg);
+    let replicas = await tx.run(SELECT('ID').from (Suppliers) .where ('ID in', msg.data.businessPartners));
+    await replicateTx(replicas.map(each => each.ID), undefined, tx, msg);
+    await tx.commit();
   })
 
   /**
@@ -57,6 +57,7 @@ module.exports = async()=>{ // called by server.js
     if (!Array.isArray(IDs)) IDs = [ IDs ]
     // 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)
     if (_initial) return db.insert (suppliers) .into (Suppliers) //> using bulk insert
@@ -65,4 +66,17 @@ module.exports = async()=>{ // called by server.js
     ))
   }
 
+  async function replicateTx (IDs,_initial, tx, msg) {
+    if (!Array.isArray(IDs)) IDs = [ IDs ]
+    // TODO: Doesn't work when running in same process with mocked API_BUSINESS_PARTNER
+
+    // TODO: Issue
+    let suppliers = await S4bupa.tx(msg).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)
+    if (_initial) return tx.insert (suppliers) .into (Suppliers) //> using bulk insert
+    else return Promise.all(suppliers.map ( //> parallelizing updates
+      each => tx.update (Suppliers,each.ID) .with (each)
+    ))
+  }
+
 }