Merge pull request #567 from bredy/RAIL-511

Add 'aggregation' to AttributeSortItem

Author: jimirocks

src/main/java/com/gooddata/executeafm/resultspec/AttributeSortAggregation.java

@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2007-2017, GoodData(R) Corporation. All rights reserved.
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE.txt file in the root directory of this source tree.
+ */
+
+package com.gooddata.executeafm.resultspec;
+
+import com.fasterxml.jackson.annotation.JsonValue;
+
+/**
+ * Represents aggregation used when putting together all related
+ * values belonging to attribute element when we are sorting by this
+ * attribute. You can find more details in {@link AttributeSortItem}.
+ */
+public enum AttributeSortAggregation {
+    SUM;
+
+    @JsonValue
+    @Override
+    public String toString() {
+        return name().toLowerCase();
+    }
+}

src/main/java/com/gooddata/executeafm/resultspec/AttributeSortItem.java

@@ -6,6 +6,7 @@
 package com.gooddata.executeafm.resultspec;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonInclude;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
 import com.fasterxml.jackson.annotation.JsonTypeName;
@@ -17,24 +18,66 @@
 
 /**
  * Define sort by specific attribute
+ *
+ * <p>With "aggregation" active you can sort all elements of attribute
+ * by "aggregation fn" applied to all valid values belonging to each
+ * element. This is extremely useful when sorting stacked
+ * visualizations like stack bar/area charts. Currently supported is
+ * only "sum", see {@link AttributeSortAggregation}</p>
+ *
+ * <p>Simple example (dimension = Year, measureGroup; 2 metrics; sort
+ * on Year with aggregation="sum", descending):</p>
+ * <pre>
+ * Year       2006        2007
+ * Names     M1  M2      M1   M2
+ * Values    1    2       3    4
+ * </pre>
+ *
+ * <p>We take all values belonging to each attribute element of chosen attribute
+ * and apply selected function (sum) on them. Notice that we are summarising
+ * values from different metrics:</p>
+ * <pre>
+ * 2006 (1 + 2 = 3)
+ * 2007 (3 + 4 = 7)
+ * </pre>
+ *
+ * <p>After that we shuffle year attribute elements related to results from "sum"
+ * function:</p>
+ * <pre>
+ * Year       2007        2006
+ * Names     M1  M2      M1   M2
+ * Values    3    4       1    2
+ * </pre>
  */
 @JsonTypeInfo(include = As.WRAPPER_OBJECT, use = Id.NAME)
 @JsonTypeName("attributeSortItem")
+@JsonInclude(JsonInclude.Include.NON_NULL)
 public class AttributeSortItem implements SortItem {
 
     private final String direction;
-
     private final String attributeIdentifier;
+    private final String aggregation;
 
     @JsonCreator
     public AttributeSortItem(@JsonProperty("direction") final String direction,
-                             @JsonProperty("attributeIdentifier") final String attributeIdentifier) {
+                             @JsonProperty("attributeIdentifier") final String attributeIdentifier,
+                             @JsonProperty("aggregation") final String aggregation) {
         this.attributeIdentifier = attributeIdentifier;
         this.direction = direction;
+        this.aggregation = aggregation;
+    }
+
+    public AttributeSortItem(final String direction,
+                             final String attributeIdentifier) {
+        this(direction, attributeIdentifier, null);
     }
 
     public AttributeSortItem(final Direction direction, final String attributeIdentifier) {
-        this(notNull(direction, "direction").toString(), attributeIdentifier);
+        this(notNull(direction, "direction").toString(), attributeIdentifier, null);
+    }
+
+    public AttributeSortItem(final Direction direction, final String attributeIdentifier, final AttributeSortAggregation aggregation) {
+        this(notNull(direction, "direction").toString(), attributeIdentifier, notNull(aggregation, "aggregation").toString());
     }
 
     public String getDirection() {
@@ -45,6 +88,10 @@ public String getAttributeIdentifier() {
         return attributeIdentifier;
     }
 
+    public String getAggregation() {
+        return aggregation;
+    }
+
     @Override
     public String toString() {
         return GoodDataToStringBuilder.defaultToString(this);

src/test/groovy/com/gooddata/executeafm/resultspec/AttributeSortItemTest.groovy

@@ -15,20 +15,29 @@ import static spock.util.matcher.HamcrestSupport.that
 class AttributeSortItemTest extends Specification {
 
     private static final String ATTRIBUTE_SORT_ITEM_JSON = 'executeafm/resultspec/attributeSortItem.json'
+    private static final String ATTRIBUTE_SORT_ITEM_WITH_AGGREGATION_JSON = 'executeafm/resultspec/attributeSortItemWithAggregation.json'
+
 
     def "should serialize values"() {
         expect:
         that new AttributeSortItem(Direction.ASC, 'aId'),
                 jsonEquals(resource(ATTRIBUTE_SORT_ITEM_JSON))
     }
 
+    def "should serialize values with aggregation"() {
+        expect:
+        that new AttributeSortItem(Direction.ASC, 'aId', AttributeSortAggregation.SUM),
+                jsonEquals(resource(ATTRIBUTE_SORT_ITEM_WITH_AGGREGATION_JSON))
+    }
+
     def "should deserialize values"() {
         when:
-        AttributeSortItem item = readObjectFromResource("/$ATTRIBUTE_SORT_ITEM_JSON", AttributeSortItem)
+        AttributeSortItem item = readObjectFromResource("/$ATTRIBUTE_SORT_ITEM_WITH_AGGREGATION_JSON", AttributeSortItem)
 
         then:
         item.attributeIdentifier == 'aId'
         item.direction == 'asc'
+        item.aggregation == 'sum'
         item.toString()
     }
 }

src/test/resources/executeafm/resultspec/attributeSortItemWithAggregation.json

@@ -0,0 +1,7 @@
+{
+  "attributeSortItem": {
+    "attributeIdentifier": "aId",
+    "direction": "asc",
+    "aggregation": "sum"
+  }
+}