Introduce messaging feature

.gitignore

@@ -53,3 +53,4 @@ dist/
 # Experimental
 xxx_*
 xxx/*
+local-messaging.txt

db/schema.cds

@@ -16,6 +16,7 @@ entity Travel : managed {
   EndDate        : Date;
   BookingFee     : Decimal(16, 3);
   TotalPrice     : Decimal(16, 3) @readonly;
+  AvgReviewRating: Decimal;
   CurrencyCode   : Currency;
   Description    : String(1024);
   TravelStatus   : Association to TravelStatus @readonly;
@@ -37,6 +38,7 @@ annotate Travel with @(
     });
 
 
+
 entity Booking : managed {
   key BookingUUID   : UUID;
   BookingID         : Integer @Core.Computed;
@@ -89,3 +91,11 @@ entity TravelStatus : CodeList {
   createDeleteHidden: Boolean;
   insertDeleteRestriction: Boolean; // = NOT createDeleteHidden
 }
+
+entity TravelReview : managed {
+  key RatingUUID : UUID;
+  TravelID : Integer;
+  Rating : Integer @assert.range: [ 0, 5 ];
+  Email : String;
+  Comment : String;
+}

local-messaging.txt

@@ -0,0 +1 @@
+sap.cap.reviews.review.changed {"data":{"subject":42,"count":1,"rating":5}}

pom.xml

@@ -112,9 +112,6 @@
                 <requireMavenVersion>
                   <version>3.5.0</version>
                 </requireMavenVersion>
-                <!-- <requireJavaVersion>
-                  <version>${jdk.version}</version>
-                </requireJavaVersion> -->
                 <requireProperty>
                   <property>project.artifactId</property>
                   <regex>[^_]+</regex>

srv/post_review.http

@@ -0,0 +1,11 @@
+POST http://localhost:8080/reviewer/TravelReview HTTP/1.1
+Authorization: Basic YXV0aGVudGljYXRlZDo=
+content-type: application/json
+
+{
+    "RatingUUID": "D5055A5D-8EED-47E3-AB38-6D646120F9DD",
+    "Rating" : 4,
+	"Email" : "[email protected]",
+	"Comment" : "awesome",
+	"TravelID" : 4132
+}

srv/review-service.cds

@@ -0,0 +1,13 @@
+using { sap.fe.cap.travel as my } from '../db/schema';
+
+service ReviewService @(path:'/reviewer') {
+
+  entity TravelReview as projection on my.TravelReview;
+
+  @topic: 'sap.cap.reviews.review.changed'
+  event Reviewed : {
+    subject : Integer;
+    count   : Integer;
+    rating  : Decimal;
+  }
+}

srv/src/main/java/com/sap/cap/sflight/processor/CreationHandler.java

@@ -11,7 +11,7 @@
 
 import com.sap.cds.ql.Select;
 import com.sap.cds.ql.Update;
-import com.sap.cds.services.cds.CdsService;
+import com.sap.cds.services.cds.CqnService;
 import com.sap.cds.services.draft.DraftService;
 import com.sap.cds.services.handler.EventHandler;
 import com.sap.cds.services.handler.annotations.Before;
@@ -42,7 +42,7 @@ public CreationHandler(PersistenceService persistenceService, DraftService draft
 		this.draftService = draftService;
 	}
 
-	@Before(event = { CdsService.EVENT_CREATE, CdsService.EVENT_UPDATE, DraftService.EVENT_DRAFT_CREATE}, entity = Travel_.CDS_NAME)
+	@Before(event = { CqnService.EVENT_CREATE, CqnService.EVENT_UPDATE, DraftService.EVENT_DRAFT_CREATE}, entity = Travel_.CDS_NAME)
 	public void setBookingDateIfNotProvided(final Travel travel) {
 		if (travel.getBeginDate() == null) {
 			travel.setBeginDate(LocalDate.now());
@@ -81,7 +81,7 @@ public void saveComputedValues(DraftActivateContext ctx) {
 		});
 	}
 
-	@Before(event = { CdsService.EVENT_CREATE, CdsService.EVENT_UPDATE }, entity = Travel_.CDS_NAME)
+	@Before(event = { CqnService.EVENT_CREATE, CqnService.EVENT_UPDATE }, entity = Travel_.CDS_NAME)
 	public void checkTravelEndDateIsAfterBeginDate(Travel travel) {
 
 		if (travel.getBeginDate() != null && travel.getEndDate() != null) {
@@ -97,7 +97,7 @@ public void checkTravelEndDateIsAfterBeginDate(Travel travel) {
 		}
 	}
 
-	@Before(event = CdsService.EVENT_CREATE, entity = Travel_.CDS_NAME)
+	@Before(event = CqnService.EVENT_CREATE, entity = Travel_.CDS_NAME)
 	public void calculateTravelIdBeforeCreation(final Travel travel) {
 		if (travel.getTravelID() == null || travel.getTravelID() == 0) {
 			Select<Travel_> maxIdSelect = Select.from(TravelService_.TRAVEL).columns(e -> e.TravelID().max().as(MAX_ID));
@@ -107,7 +107,7 @@ public void calculateTravelIdBeforeCreation(final Travel travel) {
 		}
 	}
 
-	@Before(event = { CdsService.EVENT_CREATE, CdsService.EVENT_UPDATE, }, entity = Travel_.CDS_NAME)
+	@Before(event = { CqnService.EVENT_CREATE, CqnService.EVENT_UPDATE, }, entity = Travel_.CDS_NAME)
 	public void fillBookingIdsBeforeCreationAndUpdate(final Travel travel) {
 		if (travel.getToBooking() != null) {
 			addBookingIds(travel);
@@ -152,7 +152,7 @@ private void addBookingIds(Travel travel) {
 		}
 	}
 
-	@Before(event = CdsService.EVENT_CREATE, entity = Travel_.CDS_NAME)
+	@Before(event = CqnService.EVENT_CREATE, entity = Travel_.CDS_NAME)
 	public void initialTravelStatus(final Travel travel) {
 		TravelStatus travelStatus = TravelStatus.create();
 		travelStatus.setCode("O");

srv/src/main/java/com/sap/cap/sflight/processor/RecalculatePriceHandler.java

@@ -19,7 +19,6 @@
 import com.sap.cds.ql.cqn.CqnUpdate;
 import com.sap.cds.services.ErrorStatuses;
 import com.sap.cds.services.ServiceException;
-import com.sap.cds.services.cds.CdsService;
 import com.sap.cds.services.cds.CqnService;
 import com.sap.cds.services.draft.DraftService;
 import com.sap.cds.services.handler.EventHandler;
@@ -94,7 +93,7 @@ private static BigDecimal calculateTotalPriceForTravel(CqnService db, String tra
 		return bookingFee.add(flightPriceSum).add(supplementPriceSum);
 	}
 
-	@After(event = {CdsService.EVENT_UPDATE, CdsService.EVENT_CREATE}, entity = Travel_.CDS_NAME)
+	@After(event = {CqnService.EVENT_UPDATE, CqnService.EVENT_CREATE}, entity = Travel_.CDS_NAME)
 	public void calculateNewTotalPriceForActiveTravel(Travel travel) {
 
 		/*
@@ -149,7 +148,7 @@ public void recalculateTravelPriceIfPriceWasUpdated(final BookingSupplement book
 	private BigDecimal calculateAndPatchNewTotalPriceForDraft(final String travelUUID) {
 
 		BigDecimal totalPrice = calculateTotalPriceForTravel(draftService, travelUUID, false);
-		Map<String, Object> map = new HashMap<String, Object>();
+		Map<String, Object> map = new HashMap<>();
 		map.put(Travel.TRAVEL_UUID, travelUUID);
 		map.put(Travel.TOTAL_PRICE, totalPrice);
 		CqnUpdate update = Update.entity(TRAVEL).data(map);

srv/src/main/java/com/sap/cap/sflight/processor/TravelReviewChangedHandler.java

@@ -0,0 +1,49 @@
+package com.sap.cap.sflight.processor;
+
+import static cds.gen.travelservice.Travel.AVG_REVIEW_RATING;
+import static cds.gen.travelservice.TravelService_.TRAVEL;
+
+import java.math.BigDecimal;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+
+import com.sap.cds.ql.Update;
+import com.sap.cds.services.cds.CqnService;
+import com.sap.cds.services.handler.EventHandler;
+import com.sap.cds.services.handler.annotations.On;
+import com.sap.cds.services.handler.annotations.ServiceName;
+
+import cds.gen.reviewservice.ReviewService_;
+import cds.gen.reviewservice.ReviewedContext;
+import cds.gen.travelservice.TravelService_;
+
+@Component
+@ServiceName(TravelService_.CDS_NAME)
+public class TravelReviewChangedHandler implements EventHandler {
+
+	private static final Logger logger = LoggerFactory.getLogger(TravelReviewChangedHandler.class);
+
+	private final CqnService travelService;
+
+	public TravelReviewChangedHandler(CqnService travelService) {
+		this.travelService = travelService;
+	}
+
+	@On(service = ReviewService_.CDS_NAME)
+	public void onReviewChanged(ReviewedContext context) {
+
+		BigDecimal rating = context.getData().getRating();
+		Integer travelId = context.getData().getSubject();
+
+		Map<String, Integer> updateFilter = new HashMap<>();
+		updateFilter.put("TravelID", travelId);
+
+		travelService.run(Update.entity(TRAVEL, t -> t.matching(updateFilter)).data(AVG_REVIEW_RATING, rating));
+		logger.info("Successfully updated travel with travelId {} with a new average rating of {}.", travelId, rating);
+	}
+
+}

srv/src/main/java/com/sap/cap/sflight/reviewer/ReviewHandler.java

@@ -0,0 +1,52 @@
+package com.sap.cap.sflight.reviewer;
+
+import java.math.BigDecimal;
+
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.stereotype.Component;
+
+import com.sap.cds.Row;
+import com.sap.cds.ql.Select;
+import com.sap.cds.services.cds.CqnService;
+import com.sap.cds.services.handler.EventHandler;
+import com.sap.cds.services.handler.annotations.After;
+import com.sap.cds.services.handler.annotations.ServiceName;
+
+import cds.gen.reviewservice.ReviewService_;
+import cds.gen.reviewservice.Reviewed;
+import cds.gen.reviewservice.ReviewedContext;
+import cds.gen.reviewservice.TravelReview;
+import cds.gen.reviewservice.TravelReview_;
+
+@Component
+@ServiceName(ReviewService_.CDS_NAME)
+public class ReviewHandler implements EventHandler {
+
+	private final CqnService reviewService;
+
+	public ReviewHandler(@Qualifier(ReviewService_.CDS_NAME) CqnService reviewService) {
+		this.reviewService = reviewService;
+	}
+
+	@After(event = { CqnService.EVENT_CREATE, CqnService.EVENT_UPDATE, CqnService.EVENT_UPSERT,
+			CqnService.EVENT_DELETE }, entity = TravelReview_.CDS_NAME)
+	public void afterReviewWrite(TravelReview travelReview) {
+
+		Select<TravelReview_> averageRatingQuery = Select.from(ReviewService_.TRAVEL_REVIEW)
+				.columns(t -> t.Rating().average().as("average"), t -> t.Rating().countDistinct().as("reviewCount"))
+				.where(t -> t.TravelID().eq(travelReview.getTravelID()));
+
+		Row resultRow = reviewService.run(averageRatingQuery).single();
+
+
+		Reviewed reviewed = Reviewed.create();
+		reviewed.setCount(Integer.valueOf(resultRow.get("reviewCount").toString()));
+		reviewed.setRating(BigDecimal.valueOf(5L));
+		reviewed.setSubject(travelReview.getTravelID());
+
+		ReviewedContext reviewedContext = ReviewedContext.create();
+		reviewedContext.setData(reviewed);
+
+		reviewService.emit(reviewedContext);
+	}
+}

srv/src/main/resources/application.yml

@@ -7,6 +7,7 @@ management:
 spring:
     profiles: default
     web.resources.static-locations: "file:./app"
+logging.level.com.sap.cds.messaging: DEBUG
 cds:
     security.mock.users:
     - name: rose
@@ -24,9 +25,14 @@ cds:
     odata-v4:
         endpoint:
             path: "/"
+    messaging:
+      services:
+      - name: "messaging"
+        kind: "file-based-messaging"
+        binding: "local-messaging.txt"
 
 server:
-    port: 4004
+    port: 8080
 
 ---
 spring: