From 616570a790282b96d5246edfd24a6ac1b590644a Mon Sep 17 00:00:00 2001
From: Pavol Mederly <mederly@evolveum.com>
Date: Tue, 4 Sep 2018 06:35:59 +0200
Subject: [PATCH] Add transform expression condition (MID-4862)

This is an EXPERIMENTAL implementation of condition that would
cause specified combinations of input values for an expression to
be skipped from evaluation.
---
 .../xml/ns/public/common/common-core-3.xsd    | 11 +++++
 ...alueTransformationExpressionEvaluator.java | 47 +++++++++++--------
 2 files changed, 38 insertions(+), 20 deletions(-)

diff --git a/infra/schema/src/main/resources/xml/ns/public/common/common-core-3.xsd b/infra/schema/src/main/resources/xml/ns/public/common/common-core-3.xsd
index d91d2a6d332..d9a3b6ee857 100755
--- a/infra/schema/src/main/resources/xml/ns/public/common/common-core-3.xsd
+++ b/infra/schema/src/main/resources/xml/ns/public/common/common-core-3.xsd
@@ -9223,6 +9223,17 @@
                     </xsd:appinfo>
                 </xsd:annotation>
             </xsd:element>
+			<xsd:element name="condition" type="tns:ExpressionType" minOccurs="0">
+				<xsd:annotation>
+					<xsd:documentation>
+						Condition driving whether this expression is evaluated at all (for given inputs).
+					</xsd:documentation>
+					<xsd:appinfo>
+						<a:experimental>true</a:experimental>
+						<a:since>3.9</a:since>
+					</xsd:appinfo>
+				</xsd:annotation>
+			</xsd:element>
         </xsd:sequence>
     </xsd:complexType>
     
diff --git a/model/model-common/src/main/java/com/evolveum/midpoint/model/common/expression/evaluator/AbstractValueTransformationExpressionEvaluator.java b/model/model-common/src/main/java/com/evolveum/midpoint/model/common/expression/evaluator/AbstractValueTransformationExpressionEvaluator.java
index 47180eb62ab..478f8b1a660 100644
--- a/model/model-common/src/main/java/com/evolveum/midpoint/model/common/expression/evaluator/AbstractValueTransformationExpressionEvaluator.java
+++ b/model/model-common/src/main/java/com/evolveum/midpoint/model/common/expression/evaluator/AbstractValueTransformationExpressionEvaluator.java
@@ -15,35 +15,20 @@
  */
 package com.evolveum.midpoint.model.common.expression.evaluator;
 
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.Iterator;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 import java.util.Map.Entry;
 
 import javax.xml.namespace.QName;
 
 import com.evolveum.midpoint.common.LocalizationService;
-import com.evolveum.midpoint.prism.Item;
-import com.evolveum.midpoint.prism.ItemDefinition;
-import com.evolveum.midpoint.prism.PrismPropertyValue;
-import com.evolveum.midpoint.prism.PrismValue;
+import com.evolveum.midpoint.prism.*;
 import com.evolveum.midpoint.prism.delta.DeltaSetTriple;
 import com.evolveum.midpoint.prism.delta.ItemDelta;
 import com.evolveum.midpoint.prism.delta.PlusMinusZero;
 import com.evolveum.midpoint.prism.delta.PrismValueDeltaSetTriple;
 import com.evolveum.midpoint.prism.path.ItemPath;
 import com.evolveum.midpoint.prism.polystring.PolyString;
-import com.evolveum.midpoint.repo.common.expression.ExpressionEvaluationContext;
-import com.evolveum.midpoint.repo.common.expression.ExpressionEvaluator;
-import com.evolveum.midpoint.repo.common.expression.ExpressionSyntaxException;
-import com.evolveum.midpoint.repo.common.expression.ExpressionVariables;
-import com.evolveum.midpoint.repo.common.expression.ItemDeltaItem;
-import com.evolveum.midpoint.repo.common.expression.ObjectDeltaObject;
-import com.evolveum.midpoint.repo.common.expression.Source;
-import com.evolveum.midpoint.repo.common.expression.SourceTriple;
+import com.evolveum.midpoint.repo.common.expression.*;
 import com.evolveum.midpoint.schema.constants.ExpressionConstants;
 import com.evolveum.midpoint.schema.result.OperationResult;
 import com.evolveum.midpoint.schema.util.ExceptionUtil;
@@ -350,6 +335,14 @@ private PrismValueDeltaSetTriple<V> evaluateRelativeExpression(final List<Source
 
 		final PrismValueDeltaSetTriple<V> outputTriple = new PrismValueDeltaSetTriple<>();
 
+		Expression<PrismPropertyValue<Boolean>, PrismPropertyDefinition<Boolean>> conditionExpression;
+		if (expressionEvaluatorType.getCondition() != null) {
+			conditionExpression = ExpressionUtil.createCondition(expressionEvaluatorType.getCondition(),
+					evaluationContext.getExpressionFactory(), "condition in " + contextDescription, task, result);
+		} else {
+			conditionExpression = null;
+		}
+
 		Processor<Collection<? extends PrismValue>> processor = pvalues -> {
 			if (includeNulls != null && !includeNulls && MiscUtil.isAllNull(pvalues)) {
 				// The case that all the sources are null. There is no point executing the expression.
@@ -426,8 +419,22 @@ private PrismValueDeltaSetTriple<V> evaluateRelativeExpression(final List<Source
 
 			List<V> scriptResults;
 			try {
-				scriptResults = transformSingleValue(scriptVariables, valueDestination, useNew, evaluationContext,
-						contextDescription, task, result);
+				boolean conditionResult;
+				if (conditionExpression != null) {
+					ExpressionEvaluationContext ctx = new ExpressionEvaluationContext(null, scriptVariables,
+							"condition in " + contextDescription, task, result);
+					PrismValueDeltaSetTriple<PrismPropertyValue<Boolean>> triple = conditionExpression.evaluate(ctx);
+					conditionResult = ExpressionUtil.computeConditionResult(triple.getNonNegativeValues());
+				} else {
+					conditionResult = true;
+				}
+				if (conditionResult) {
+					scriptResults = transformSingleValue(scriptVariables, valueDestination, useNew, evaluationContext,
+							contextDescription, task, result);
+				} else {
+					LOGGER.trace("Skipping value transformation because condition evaluated to false in {}", contextDescription);
+					scriptResults = Collections.emptyList();
+				}
 			} catch (ExpressionEvaluationException e) {
 				throw new TunnelException(
 						localizationService.translate(