TransformationUtils: Simplify createTransformedObjectFor's logic

Issue-Ref: 3620
Issue-Url: https://af3-developer.fortiss.org/issues/3620


Signed-off-by: Alexander Diewald <diewald@fortiss.org>

org.fortiss.tooling.kernel/src/org/fortiss/tooling/kernel/utils/.ratings

@@ -11,5 +11,5 @@ KernelModelElementUtils.java 56c86fe9afb23053f50d7279809afd2a5bb10eba GREEN
 LoggingUtils.java 0e0aa5d466d80ea29cfc7e91178b23a5cdd4ddf7 GREEN
 PrototypesUtils.java ec75bed75cfc5103f1f38e3a29df86f729428775 GREEN
 ResourceUtils.java 698c7db34acb4f1a258a1953e6afcca9823763a8 GREEN
-TransformationUtils.java 495891fae79b99c103cf61f607792dd1e48a5307 GREEN
+TransformationUtils.java 552d3a9d56d34450be781af828efe0b8aa5d359e YELLOW
 UniqueIDUtils.java 665955b1790c1bd1c2087e23114da920bfec2265 GREEN

org.fortiss.tooling.kernel/src/org/fortiss/tooling/kernel/utils/TransformationUtils.java

@@ -15,6 +15,8 @@
 +--------------------------------------------------------------------------*/
 package org.fortiss.tooling.kernel.utils;
 
+import static org.eclipse.core.runtime.Assert.isNotNull;
+
 import java.util.List;
 
 import org.eclipse.emf.ecore.EObject;
@@ -45,31 +47,28 @@ public final class TransformationUtils {
 	 *             if no transformation chain could be found or none of the
 	 *             possible chains succeeded.
 	 */
-	@SuppressWarnings("unchecked")
 	public static <T extends Object> T createTransformedObjectFor(final EObject sourceElement,
 			final Class<T> targetClass, ITransformationContext context)
 			throws ChainTransformationFailedException {
 		List<TransformationProviderChain> chainList = ITransformationService.getInstance()
 				.getTransformationProviderChain(sourceElement.getClass(), targetClass, context);
-		ChainTransformationFailedException e = null;
 		if(!chainList.isEmpty()) {
-			Object executableObject = null;
 			for(TransformationProviderChain chain : chainList) {
 				try {
-					// For the moment, we use the first chain.
+					// For the moment, we use the first chain that successfully completes.
 					// Alternatives need an interpretation of the context, which
 					// we do not use at the moment.
-					executableObject = chain.transform(sourceElement, context);
-					e = null;
-					break;
+					@SuppressWarnings("unchecked") T executableObject =
+							(T)chain.transform(sourceElement, context);
+					isNotNull(executableObject, "The resulting object of the transformation" +
+							" of the object " + sourceElement + " to " +
+							targetClass.getSimpleName() + "is null, but did not fail. Please" +
+							" ensure correct operation of all involved TransformationProviders.");
+					return executableObject;
 				} catch(ChainTransformationFailedException ctfe) {
 					// fall through
-					e = ctfe;
 				}
 			}
-			if(e == null && executableObject != null) {
-				return (T)executableObject;
-			}
 		}
 		throw new NoTransformationChainFound(sourceElement, targetClass);
 	}