Add test for empty processChain.

Changed the warning message from "No processChain steps are defined for this processChain. Such processChains have no effect and should be omitted." to "No processChain steps are defined for this processChain. A processChain should have at least one step showing a view.".

de.wwu.md2.framework.tests/models/de/wwu/md2/framework/tests/dsl/controller/validator/EmptyProcessChain.md2

@@ -0,0 +1,15 @@
+package TestProject.controllers
+
+WorkflowElement Test {
+    defaultProcessChain TestChain
+
+    onInit {
+        action CustomAction init {
+
+        }
+    }
+
+    processChain TestChain {
+
+    }
+}

de.wwu.md2.framework.tests/src/de/wwu/md2/framework/tests/dsl/controller/validator/ValidatorTests.xtend

@@ -21,6 +21,9 @@ import de.wwu.md2.framework.mD2.Validator
 import java.util.List
 import de.wwu.md2.framework.mD2.CustomAction
 import de.wwu.md2.framework.mD2.ValidatorBindingTask
+import de.wwu.md2.framework.mD2.MD2Package
+import de.wwu.md2.framework.validation.ControllerValidator
+import de.wwu.md2.framework.mD2.WorkflowElement
 
 @InjectWith(typeof(MD2InjectorProvider))
 @RunWith(typeof(XtextRunner))
@@ -32,6 +35,7 @@ class ValidatorTests {
 	MD2Model viewModel;
 	MD2Model rootValidatorModel; 
 	MD2Model inputFieldValidatorModel; 
+	MD2Model emptyProcessChainModel;
 	ResourceSet rs;
 
 	private EList<ControllerElement> elements;
@@ -48,6 +52,7 @@ class ValidatorTests {
 		mainModel = BASIC_CONTROLLER_M.load.parse(rs);
 		rootValidatorModel = VALIDATOR_COMPONENT_C.load.parse(rs);
 		inputFieldValidatorModel = INPUT_FIELD_VALIDATOR_COMPONENT_C.load.parse(rs);
+		emptyProcessChainModel = EMPTY_PROCESS_CHAIN_C.load.parse;
 
 		elements = (rootValidatorModel.modelLayer as Controller).controllerElements;
 		validators = elements.filter(typeof(Validator)).toList;
@@ -101,7 +106,12 @@ class ValidatorTests {
 		1.assertEquals(tasks.get(1).validators.size);
 		1.assertEquals(tasks.get(2).validators.size);
 		1.assertEquals(tasks.get(3).validators.size);
-	} 
+	}
+
+	@Test
+	def checkForEmptyProcessChainsTest(){
+	    emptyProcessChainModel.assertWarning(MD2Package::eINSTANCE.processChain, ControllerValidator::EMPTYPROCESSCHAIN);
+	}
 
 
 }

de.wwu.md2.framework.tests/src/de/wwu/md2/framework/tests/utils/ModelProvider.java

@@ -51,6 +51,8 @@ public class ModelProvider {
 	public static final String VALIDATOR_COMPONENT_C = "dsl/controller/validator/RootValidators.md2";
 
 	public static final String INPUT_FIELD_VALIDATOR_COMPONENT_C = "dsl/controller/validator/InputFieldValidators.md2";
+
+	public static final String EMPTY_PROCESS_CHAIN_C = "dsl/controller/validator/EmptyProcessChain.md2";
 
 	//********Validator*****//
 

de.wwu.md2.framework/src/de/wwu/md2/framework/validation/ControllerValidator.xtend

@@ -31,7 +31,9 @@ class ControllerValidator extends AbstractMD2JavaValidator {
 	@Inject
     override register(EValidatorRegistrar registrar) {
         // nothing to do
-    }   
+    }
+
+    public static final String EMPTYPROCESSCHAIN = "emptyProcessChain";
 
     /////////////////////////////////////////////////////////
 	/// Action Validators
@@ -263,5 +265,18 @@ class ControllerValidator extends AbstractMD2JavaValidator {
 			val error = '''No subsequent step! Cannot define 'proceed' operation on last processChain step.'''
 			acceptError(error, next, null, -1, null);
 		}
-	}	
+	}
+
+	/**
+     * Avoid empty processChains.
+     * @param processChain
+     */
+    @Check
+    def checkForEmptyProcessChains(ProcessChain processChain) {
+        if(processChain.processChainSteps.empty) {
+            acceptWarning("No processChain steps are defined for this processChain. A processChain should have at least one step showing a view.",
+                    processChain, null, -1, EMPTYPROCESSCHAIN);
+        }
+    }
+
 }

de.wwu.md2.framework/src/de/wwu/md2/framework/validation/LegacyValidator.java

@@ -450,18 +450,6 @@ public void checkAbstractViewGUIElementRef_Path(AbstractViewGUIElementRef abstra
 		}
 	}
 
-	/**
-	 * Avoid empty processChains.
-	 * @param processChain
-	 */
-	@Check
-	public void checkForEmptyProcessChains(ProcessChain processChain) {
-		if(processChain.getProcessChainSteps().isEmpty()) {
-			acceptWarning("No processChain steps are defined for this processChain. Such processChains have no effect and should be omitted.",
-					processChain, null, -1, null);
-		}
-	}
-
 	/**
 	 * This validator avoids the assignment of none-toMany content providers (providing X[]) to ContentProviderAddActions.
 	 * @param addAction