Showcase how to integrate DB-specific functions (#201)

Augment `AdminService.Author` by 2 fields `age` and `lifetime` whose
values are computed by SQLite and HANA-specific functions.

Don't do this in bookshop directly, to keep it simple.  Instead, use
the fiori module, which also allows to integrate the fields in the UI.

Co-authored-by: Daniel <daniel.hutzel@sap.com>

fiori/app/_i18n/i18n.properties

@@ -11,6 +11,7 @@ DateOfBirth = Date of Birth
 DateOfDeath = Date of Death
 PlaceOfBirth = Place of Birth
 PlaceOfDeath = Place of Death
+Age = Age
 Authors = Authors
 Order = Order
 Orders = Orders

fiori/app/_i18n/i18n_de.properties

@@ -6,6 +6,7 @@ Authors = Autoren
 Author = Autor
 AuthorID = ID des Autors
 AuthorName = Name des Autors
+Age = Alter
 Name = Name
 Stock = Bestand
 Order = Bestellung

fiori/app/admin/fiori-service.cds

@@ -1,4 +1,4 @@
-using AdminService from '@capire/bookshop';
+using { AdminService } from '../../db';
 
 ////////////////////////////////////////////////////////////////////////////
 //
@@ -39,6 +39,27 @@ annotate AdminService.Books with @(
 	}
 );
 
+annotate AdminService.Authors with @(
+	UI: {
+		HeaderInfo: {
+			Description: {Value: lifetime}
+		},
+		Facets: [
+			{$Type: 'UI.ReferenceFacet', Label: '{i18n>Details}', Target: '@UI.FieldGroup#Details'},
+			{$Type: 'UI.ReferenceFacet', Label: '{i18n>Books}', Target: 'books/@UI.LineItem'},
+		],
+		FieldGroup#Details: {
+			Data: [
+				{Value: placeOfBirth},
+				{Value: placeOfDeath},
+				{Value: dateOfBirth},
+				{Value: dateOfDeath},
+				{Value: age, Label: '{i18n>Age}'},
+			]
+		},
+	}
+);
+
 
 
 ////////////////////////////////////////////////////////////

fiori/db/hana/index.cds

@@ -0,0 +1,10 @@
+//
+//  Add Author.age and .lifetime with a DB-specific function
+//
+
+using { AdminService } from '..';
+
+extend projection AdminService.Authors with {
+  YEARS_BETWEEN(dateOfBirth, dateOfDeath)         as age: Integer,
+  YEAR(dateOfBirth) || ' – ' || YEAR(dateOfDeath) as lifetime : String
+}

fiori/db/index.cds

@@ -0,0 +1,8 @@
+using { sap.capire.bookshop } from '@capire/bookshop';
+
+// Forward-declare calculated fields to be filled in database-specific ways
+// TODO find a better way to have 'default' fields that still can be overwritten.
+extend bookshop.Authors with {
+	virtual age: Integer;
+	virtual lifetime: String;
+}

fiori/db/sqlite/index.cds

@@ -0,0 +1,10 @@
+//
+//  Add Author.age and .lifetime with a DB-specific function
+//
+
+using { AdminService } from '..';
+
+extend projection AdminService.Authors with {
+  strftime('%Y',dateOfDeath)-strftime('%Y',dateOfBirth)              as age: Integer,
+  strftime('%Y',dateOfBirth) || ' – ' || strftime('%Y',dateOfDeath)  as lifetime : String
+}

fiori/package.json

@@ -8,7 +8,7 @@
     "@capire/common": "*",
     "@sap/cds": "^4",
     "express": "^4.17.1",
-    "passport": "0.4.1"
+    "passport": "^0.4.1"
   },
   "scripts": {
     "start": "cds run --in-memory?",
@@ -23,8 +23,14 @@
         "kind": "odata", "model": "@capire/orders"
       },
       "db": {
-        "kind": "sql"
+        "kind": "sql",
+        "[development]": {
+          "model": "db/sqlite"
+        },
+        "[production]": {
+          "model": "db/hana"
+        }
       }
     }
   }
-}
+}

fiori/test/requests.http

@@ -63,3 +63,15 @@ Content-Type: application/json
 
 ### Get active order
 GET {{bookshop}}/orders/Orders(ID={{newOrderID}},IsActiveEntity=true)
+
+### Create author
+POST {{bookshop}}/admin/Authors
+Content-Type: application/json
+Authorization: Basic alice:
+
+{
+  "ID": 200,
+  "name": "William Shakespeare",
+  "dateOfBirth": "1564-04-26",
+  "dateOfDeath": "1616-04-23"
+}