diff --git a/AlgebraicDataflowArchitectureModel/src/algorithms/DataTransferModelAnalyzer.java b/AlgebraicDataflowArchitectureModel/src/algorithms/DataTransferModelAnalyzer.java
index 6cfd4e7..69fe530 100644
--- a/AlgebraicDataflowArchitectureModel/src/algorithms/DataTransferModelAnalyzer.java
+++ b/AlgebraicDataflowArchitectureModel/src/algorithms/DataTransferModelAnalyzer.java
@@ -28,25 +28,26 @@
 		channels.addAll(model.getChannels());
 		for (Channel channel: channels) {
 			for (ChannelMember member: ((DataTransferChannel) channel).getOutputChannelMembers()) {
-				boolean flag = !member.getStateTransition().isRightUnary();		// The state does not need to be stored if the state transition function is right unary.
+				boolean toBeStored = !member.getStateTransition().isRightUnary();		// The state does not need to be stored if the state transition function is right unary.
 				for (Node node : graph.getResourceNodes()) {
 					if (((ResourceNode) node).getInSideResources().contains(member.getResource())) {
-						setStoreAttribute((ResourceNode) node, flag);
+						setStoreAttribute((ResourceNode) node, toBeStored);
 					}
 				}
 			}
 		}
-		for (Node node : graph.getResourceNodes()) {
+		for (Node node: graph.getResourceNodes()) {
 			HashSet<Channel> inChannels = new HashSet<>();
-			for(Edge pre : ((ResourceNode) node).getInEdges()) {
-				if (pre instanceof DataFlowEdge) {
-					DataFlowEdge dfEdge = (DataFlowEdge) pre;
+			for(Edge inEdge: ((ResourceNode) node).getInEdges()) {
+				if (inEdge instanceof DataFlowEdge) {
+					DataFlowEdge dfEdge = (DataFlowEdge) inEdge;
 					if (dfEdge.isChannelToResource()) {
 						inChannels.add(((ChannelNode) dfEdge.getSource()).getChannel());
 					}
 				}
 			}
 			if ((inChannels.size() > 1)) {
+				// If the resource has multiple input channels, then the state of the resource needs to be stored.
 				setStoreAttribute((ResourceNode) node, true);
 			} else if (((ResourceNode) node).getAttribute() == null) {
 				setStoreAttribute((ResourceNode) node, false);
@@ -55,15 +56,15 @@
 		return graph;
 	}
 
-	static private void setStoreAttribute(ResourceNode node, boolean flag) {
+	static private void setStoreAttribute(ResourceNode node, boolean toBeStored) {
 		NodeAttribute attr = node.getAttribute();
 		StoreAttribute store;
 		if (attr != null && attr instanceof NodeAttribute) {
 			store = (StoreAttribute) attr;
-			store.setNeeded(store.isNeeded() || flag);
+			store.setNeeded(store.isNeeded() || toBeStored);
 		} else {
 			store = new StoreAttribute();
-			store.setNeeded(flag);
+			store.setNeeded(toBeStored);
 			node.setAttribute(store);
 		}
 	}
diff --git a/AlgebraicDataflowArchitectureModel/src/generators/CodeGenerator.java b/AlgebraicDataflowArchitectureModel/src/generators/CodeGenerator.java
index d1cb9de..ae6acca 100644
--- a/AlgebraicDataflowArchitectureModel/src/generators/CodeGenerator.java
+++ b/AlgebraicDataflowArchitectureModel/src/generators/CodeGenerator.java
@@ -257,18 +257,26 @@
 	}
 
 	protected void addReference(TypeDeclaration component, MethodDeclaration constructor, Node dstNode, ILanguageSpecific langSpec) {
-		String dstNodeName = null;
+		ResourcePath dstRes = null;
+		String dstComponentName = null;
 		if (dstNode instanceof ResourceNode) {
-			dstNodeName = ((ResourceNode) dstNode).getResourceName();
+			dstRes = ((ResourceNode) dstNode).getOutSideResource();
+			if (generatesComponent(dstRes.getResourceHierarchy())) {
+				dstComponentName = getComponentName(((ResourceNode) dstNode).getResourceHierarchy(), langSpec);
+			} else {
+				dstComponentName = getComponentName(((ResourceNode) dstNode).getResourceHierarchy().getParent(), langSpec);
+			}
 		}
-		String dstComponentName = langSpec.toComponentName(dstNodeName);
-		if (langSpec.declareField()) {
-			// Declare a field to refer to another component.
-			component.addField(langSpec.newFieldDeclaration(new Type(dstComponentName, dstComponentName), dstNodeName));
+		if (dstComponentName != null) {
+			String dstNodeName = langSpec.toVariableName(dstComponentName);
+			if (langSpec.declareField()) {
+				// Declare a field to refer to another component.
+				component.addField(langSpec.newFieldDeclaration(new Type(dstComponentName, dstComponentName), dstNodeName));
+			}
+			// Initialize the field to refer to another component.
+			constructor.addParameter(langSpec.newVariableDeclaration(new Type(dstComponentName, dstComponentName), dstNodeName));
+			constructor.getBody().addStatement(langSpec.getFieldAccessor(dstNodeName) + langSpec.getAssignment() + dstNodeName + langSpec.getStatementDelimiter());
 		}
-		// Initialize the field to refer to another component.
-		constructor.addParameter(langSpec.newVariableDeclaration(new Type(dstComponentName, dstComponentName), dstNodeName));
-		constructor.getBody().addStatement(langSpec.getFieldAccessor(dstNodeName) + langSpec.getAssignment() + dstNodeName + langSpec.getStatementDelimiter());
 	}
 
 	protected void fillStateGetterMethod(MethodDeclaration stateGetter, ResourceHierarchy resourceHierarchy, Type resStateType, ILanguageSpecific langSpec) {
@@ -390,13 +398,13 @@
 		for (Channel ch : model.getChannels()) {
 			DataTransferChannel c = (DataTransferChannel) ch;
 			if (c.getInputResources().contains(resourceNode.getOutSideResource())) {
-				for (ResourcePath id: c.getReferenceResources()) {
-					if (!refs.contains(id) && !depends.contains(id)) {
-						refs.add(id);
-						String refResName = langSpec.toComponentName(id.getResourceName());
-						component.addField(langSpec.newFieldDeclaration(new Type(refResName, refResName), id.getResourceName()));
-						constructor.addParameter(langSpec.newVariableDeclaration(new Type(refResName, refResName), id.getResourceName()));						
-						constructor.getBody().addStatement(langSpec.getFieldAccessor(id.getResourceName()) + langSpec.getAssignment() + id.getResourceName() + langSpec.getStatementDelimiter());
+				for (ResourcePath res: c.getReferenceResources()) {
+					if (!refs.contains(res) && !depends.contains(res)) {
+						refs.add(res);
+						String refResName = langSpec.toComponentName(res.getResourceName());
+						component.addField(langSpec.newFieldDeclaration(new Type(refResName, refResName), res.getResourceName()));
+						constructor.addParameter(langSpec.newVariableDeclaration(new Type(refResName, refResName), res.getResourceName()));						
+						constructor.getBody().addStatement(langSpec.getFieldAccessor(res.getResourceName()) + langSpec.getAssignment() + res.getResourceName() + langSpec.getStatementDelimiter());
 					}
 				}
 			}
diff --git a/AlgebraicDataflowArchitectureModel/src/generators/CodeGeneratorFromDataFlowGraph.java b/AlgebraicDataflowArchitectureModel/src/generators/CodeGeneratorFromDataFlowGraph.java
index 5e43545..7b4edb8 100644
--- a/AlgebraicDataflowArchitectureModel/src/generators/CodeGeneratorFromDataFlowGraph.java
+++ b/AlgebraicDataflowArchitectureModel/src/generators/CodeGeneratorFromDataFlowGraph.java
@@ -51,6 +51,7 @@
 		Map<ResourceHierarchy, TypeDeclaration> resourceComponents = new HashMap<>();
 		List<Map.Entry<ResourceHierarchy, MethodDeclaration>> getters = new ArrayList<>();
 		List<Map.Entry<ResourceHierarchy, MethodDeclaration>> inputs = new ArrayList<>();
+		List<Map.Entry<ResourceHierarchy, FieldDeclaration>> fields = new ArrayList<>();
 		
 		// For each components.
 		for (Node componentNode: components) {
@@ -70,20 +71,20 @@
 					CompilationUnit cu = langSpec.newCompilationUnit(component);
 					codes.add(cu);
 					
+					// Declare the constructor and the fields to refer to other resources.
+					MethodDeclaration constructor = declareConstructorAndFieldsToReferToResources(resourceNode, component, depends, langSpec);
+					
 					if (resourceNode.getResourceHierarchy().getParent() == null) {
 						// For each root resource
-						// Declare the constructor and the fields to refer to other resources.
-						MethodDeclaration constructor = declareConstructorAndFieldsToReferToResources(resourceNode, component, depends, langSpec);
-						
 						// Update the main component for this component.
 						updateMainComponent(model, mainComponent, mainConstructor, componentNode, depends, langSpec);
-						
-						// Declare the fields to refer to reference resources.
-						declareFieldsToReferenceResources(model, resourceNode, component, constructor, depends, langSpec);				
-						
-						if (constructor.getParameters() == null) {
-							component.removeMethod(constructor);
-						}
+					}
+					
+					// Declare the fields to refer to reference resources.
+					declareFieldsToReferenceResources(model, resourceNode, component, constructor, depends, langSpec);				
+					
+					if (constructor.getParameters() == null) {
+						component.removeMethod(constructor);
 					}
 				}
 				
@@ -98,6 +99,12 @@
 				// Declare cache fields and update methods in this resource.
 				List<MethodDeclaration> updates = declareCacheFieldsAndUpdateMethods(resourceNode, component, langSpec);
 			}
+			
+			// Declare the state field and reference fields in the parent component.
+			if (component == null) {
+				declareFieldsInParentComponent(resourceNode, fields, langSpec);
+			}
+			
 			// Declare the getter method in this resource to obtain the state.
 			MethodDeclaration stateGetter = declareStateGetterMethod(resourceNode, component, resStateType, langSpec);
 			if (component == null) {
@@ -127,10 +134,14 @@
 		for (Map.Entry<ResourceHierarchy, MethodDeclaration> entry: inputs) {
 			resourceComponents.get(entry.getKey()).addMethod(entry.getValue());
 		}
+		
+		// Add leaf reference fields to the parent components.
+		for (Map.Entry<ResourceHierarchy, FieldDeclaration> entry: fields) {
+			resourceComponents.get(entry.getKey()).addField(entry.getValue());
+		}
 	}
 	
-	private MethodDeclaration declareConstructorAndFieldsToReferToResources(ResourceNode resourceNode, TypeDeclaration component, 
-			List<ResourcePath> depends, ILanguageSpecific langSpec) {
+	private MethodDeclaration declareConstructorAndFieldsToReferToResources(ResourceNode resourceNode, TypeDeclaration component, List<ResourcePath> depends, ILanguageSpecific langSpec) {
 		// Declare a constructor in each component.
 		MethodDeclaration constructor = component.createConstructor();
 		Block block = new Block();
@@ -138,7 +149,22 @@
 		
 		// Declare fields in each component. (for data-flow graph)
 		for (Edge resToCh: resourceNode.getOutEdges()) {
-			if (((PushPullAttribute) ((DataFlowEdge) resToCh).getAttribute()).getOptions().get(0) == PushPullValue.PUSH) {
+			DataTransferChannel ch = ((ChannelNode) resToCh.getDestination()).getChannel();
+			// Check if the input resource is outside of the channel scope.
+			boolean outsideInputResource = false;
+			if (ch.getAllSelectors().size() > 0) {
+				Set<Expression> params = new HashSet<>();
+				for (Selector s: ch.getAllSelectors()) {
+					params.add(s.getExpression());
+				}
+				for (ChannelMember cm: ch.getInputChannelMembers()) {
+					if (cm.getResource().getResourceHierarchy().equals(resourceNode.getResourceHierarchy()) && !params.containsAll(cm.getResource().getPathParams())) {
+						outsideInputResource = true;	// Regarded as pull transfer.
+						break;
+					}
+				}
+			}
+			if (((PushPullAttribute) ((DataFlowEdge) resToCh).getAttribute()).getOptions().get(0) == PushPullValue.PUSH && !outsideInputResource) {
 				for (Edge chToRes: resToCh.getDestination().getOutEdges()) {
 					// for PUSH transfer
 					addReference(component, constructor, chToRes.getDestination(), langSpec);
@@ -149,10 +175,32 @@
 		}
 		for (Edge chToRes: resourceNode.getInEdges()) {
 			for (Edge resToCh: chToRes.getSource().getInEdges()) {
-				if (((PushPullAttribute) ((DataFlowEdge) resToCh).getAttribute()).getOptions().get(0) != PushPullValue.PUSH) {
+				ResourcePath srcRes = ((ResourceNode) resToCh.getSource()).getOutSideResource();
+				DataTransferChannel ch = ((ChannelNode) resToCh.getDestination()).getChannel();
+				// Check if the input and output resources are outside of the channel scope.
+				boolean outsideInputResource = false;
+				boolean outsideOutputResource = false;
+				if (ch.getAllSelectors().size() > 0) {
+					Set<Expression> params = new HashSet<>();
+					for (Selector s: ch.getAllSelectors()) {
+						params.add(s.getExpression());
+					}
+					for (ChannelMember cm: ch.getInputChannelMembers()) {
+						if (cm.getResource().getResourceHierarchy().equals(srcRes.getResourceHierarchy()) && !params.containsAll(cm.getResource().getPathParams())) {
+							outsideInputResource = true;	// Regarded as pull transfer.
+							break;
+						}
+					}
+					for (ChannelMember cm: ch.getOutputChannelMembers()) {
+						if (cm.getResource().getResourceHierarchy().equals(resourceNode.getOutSideResource().getResourceHierarchy()) && !params.containsAll(cm.getResource().getPathParams())) {
+							outsideOutputResource = true;	// Regarded as push transfer.
+							break;
+						}
+					}
+				}
+				if ((((PushPullAttribute) ((DataFlowEdge) resToCh).getAttribute()).getOptions().get(0) != PushPullValue.PUSH && !outsideOutputResource) || outsideInputResource) {
 					// for PULL transfer
 					addReference(component, constructor, resToCh.getSource(), langSpec);
-					ResourcePath srcRes = ((ResourceNode) resToCh.getSource()).getOutSideResource();
 					if (!depends.contains(srcRes)) depends.add(srcRes);
 				}
 			}
@@ -160,8 +208,7 @@
 		return constructor;
 	}
 	
-	private void declareStateField(ResourceNode resourceNode, TypeDeclaration component, Type resStateType,
-			ILanguageSpecific langSpec) {
+	private void declareStateField(ResourceNode resourceNode, TypeDeclaration component, Type resStateType, ILanguageSpecific langSpec) {
 		Set<ResourceHierarchy> children = resourceNode.getResourceHierarchy().getChildren();
 		if (children == null || children.size() == 0) {
 			// leaf resource.
@@ -178,21 +225,95 @@
 				for (ResourceHierarchy c: children) {
 					String childTypeName = getComponentName(c, langSpec);
 					Type childType = null;
-					if ((c.getChildren() == null || c.getChildren().size() == 0) && c.getNumParameters() == 0) {
-						// The child does not have a component.
-						childType = c.getResourceStateType();
-					} else {
+					if (generatesComponent(c)) {
 						// The child has a component.
 						childType = new Type(childTypeName, childTypeName);
+						String fieldName = langSpec.toVariableName(childTypeName);
+						FieldDeclaration stateField = langSpec.newFieldDeclaration(childType, fieldName, langSpec.getFieldInitializer(resStateType, resourceNode.getResourceHierarchy().getInitialValue()));
+						component.addField(stateField);
 					}
-					String fieldName = langSpec.toVariableName(childTypeName);
-					FieldDeclaration stateField = langSpec.newFieldDeclaration(childType, fieldName, langSpec.getFieldInitializer(resStateType, resourceNode.getResourceHierarchy().getInitialValue()));
-					component.addField(stateField);
 				}
 			}
 		}
 	}
 
+	private void declareFieldsInParentComponent(ResourceNode resourceNode, List<Map.Entry<ResourceHierarchy, FieldDeclaration>> fields, ILanguageSpecific langSpec) {
+		// Declare reference fields for push/pull data transfer.
+		boolean noPullTransfer = true;
+		for (Edge resToCh : resourceNode.getOutEdges()) {
+			DataFlowEdge re = (DataFlowEdge) resToCh;
+			DataTransferChannel ch = ((ChannelNode) re.getDestination()).getChannel();
+			for (Edge chToRes: re.getDestination().getOutEdges()) {
+				ResourcePath dstRes = ((ResourceNode) chToRes.getDestination()).getOutSideResource();
+				// Check if the destination resource is outside of the channel scope.
+				boolean outsideOutputResource = false;
+				if (ch.getAllSelectors().size() > 0) {
+					Set<Expression> params = new HashSet<>();
+					for (Selector s: ch.getAllSelectors()) {
+						params.add(s.getExpression());
+					}
+					for (ChannelMember cm: ch.getOutputChannelMembers()) {
+						if (cm.getResource().getResourceHierarchy().equals(dstRes.getResourceHierarchy()) && !params.containsAll(cm.getResource().getPathParams())) {
+							outsideOutputResource = true;	// Regarded as push transfer.
+							break;
+						}
+					}
+				}
+				if (outsideOutputResource) {
+					// Declare a field in the parent component to refer to the destination resource of push transfer.
+					String dstResName = null;
+					if (generatesComponent(dstRes.getResourceHierarchy())) {
+						dstResName = getComponentName(dstRes.getResourceHierarchy(), langSpec);
+					} else {
+						dstResName = getComponentName(dstRes.getResourceHierarchy().getParent(), langSpec);
+					}
+					FieldDeclaration refFieldForPush = langSpec.newFieldDeclaration(new Type(dstResName, dstResName), langSpec.toVariableName(dstResName));
+					fields.add(new AbstractMap.SimpleEntry(resourceNode.getParent().getResourceHierarchy(), refFieldForPush));
+				}
+			}
+		}
+		for (Edge chToRes : resourceNode.getInEdges()) {
+			for (Edge resToCh: chToRes.getSource().getInEdges()) {
+				DataFlowEdge re = (DataFlowEdge) resToCh;
+				ResourcePath srcRes = ((ResourceNode) re.getSource()).getOutSideResource();
+				DataTransferChannel ch = ((ChannelNode) re.getDestination()).getChannel();
+				// Check if the source resource is outside of the channel scope.
+				boolean outsideInputResource = false;
+				if (ch.getAllSelectors().size() > 0) {
+					Set<Expression> params = new HashSet<>();
+					for (Selector s: ch.getAllSelectors()) {
+						params.add(s.getExpression());
+					}
+					for (ChannelMember cm: ch.getInputChannelMembers()) {
+						if (cm.getResource().getResourceHierarchy().equals(srcRes.getResourceHierarchy()) && !params.containsAll(cm.getResource().getPathParams())) {
+							outsideInputResource = true;	// Regarded as pull transfer.
+							break;
+						}
+					}
+				}
+				if (outsideInputResource) {
+					// Declare a field in the parent component to refer to the source resource of pull transfer.
+					String srcResName = null;
+					if (generatesComponent(srcRes.getResourceHierarchy())) {
+						srcResName = getComponentName(srcRes.getResourceHierarchy(), langSpec);
+					} else {
+						srcResName = getComponentName(srcRes.getResourceHierarchy().getParent(), langSpec);
+					}
+					FieldDeclaration refFieldForPull = langSpec.newFieldDeclaration(new Type(srcResName, srcResName), langSpec.toVariableName(srcResName));
+					fields.add(new AbstractMap.SimpleEntry(resourceNode.getParent().getResourceHierarchy(), refFieldForPull));
+					noPullTransfer = false;
+				}
+			}
+		}
+		// Declare the state field in the parent component.
+		ResourceHierarchy res = resourceNode.getOutSideResource().getResourceHierarchy();
+		if (((StoreAttribute) resourceNode.getAttribute()).isStored() && noPullTransfer && res.getNumParameters() == 0) {
+			String resName = getComponentName(res, langSpec);
+			FieldDeclaration stateField = langSpec.newFieldDeclaration(res.getResourceStateType(), langSpec.toVariableName(resName));
+			fields.add(new AbstractMap.SimpleEntry(resourceNode.getParent().getResourceHierarchy(), stateField));
+		}
+	}
+	
 	private MethodDeclaration declareStateGetterMethod(ResourceNode resourceNode, TypeDeclaration component, Type resStateType, ILanguageSpecific langSpec) {
 		// Declare the getter method of the resource state.
 		MethodDeclaration stateGetter = null;
@@ -284,7 +405,7 @@
 		// Declare the getter methods in this resource to obtain the children resources.
 		for (ResourceNode child: resourceNode.getChildren()) {
 			if (generatesComponent(child.getResourceHierarchy())) {
-				// A component is generated for the child.
+				// A component for the child is generated.
 				List<VariableDeclaration> params = new ArrayList<>();
 				int v = 1;
 				for (Selector param: child.getSelectors()) {
diff --git a/AlgebraicDataflowArchitectureModel/src/generators/JavaCodeGenerator.java b/AlgebraicDataflowArchitectureModel/src/generators/JavaCodeGenerator.java
index d37aa16..2833000 100644
--- a/AlgebraicDataflowArchitectureModel/src/generators/JavaCodeGenerator.java
+++ b/AlgebraicDataflowArchitectureModel/src/generators/JavaCodeGenerator.java
@@ -128,6 +128,7 @@
 		Map<ResourceHierarchy, TypeDeclaration> resourceTypes = new HashMap<>();
 		List<Map.Entry<ResourceHierarchy, MethodDeclaration>> getters = new ArrayList<>();
 		List<Map.Entry<ResourceHierarchy, MethodDeclaration>> inputs = new ArrayList<>();
+		List<Map.Entry<ResourceHierarchy, FieldDeclaration>> fields = new ArrayList<>();
 
 		TypeDeclaration mainType = new TypeDeclaration(mainTypeName);
 		CompilationUnit mainCU = new CompilationUnit(mainType);
@@ -222,14 +223,34 @@
 					depends = new HashSet<>();
 					for (Edge resToCh : rn.getOutEdges()) {
 						DataFlowEdge re = (DataFlowEdge) resToCh;
-						if (((PushPullAttribute) re.getAttribute()).getOptions().get(0) == PushPullValue.PUSH) {
+						DataTransferChannel ch = ((ChannelNode) re.getDestination()).getChannel();
+						// Check if the input resource is outside of the channel scope.
+						boolean outsideInputResource = false;
+						if (ch.getAllSelectors().size() > 0) {
+							Set<Expression> params = new HashSet<>();
+							for (Selector s: ch.getAllSelectors()) {
+								params.add(s.getExpression());
+							}
+							for (ChannelMember cm: ch.getInputChannelMembers()) {
+								if (cm.getResource().getResourceHierarchy().equals(rn.getResourceHierarchy()) && !params.containsAll(cm.getResource().getPathParams())) {
+									outsideInputResource = true;	// Regarded as pull transfer.
+									break;
+								}
+							}
+						}
+						if (((PushPullAttribute) re.getAttribute()).getOptions().get(0) == PushPullValue.PUSH && !outsideInputResource) {
 							// Declare a field to refer to the destination resource of push transfer.
 							for (Edge chToRes: re.getDestination().getOutEdges()) {
 								ResourcePath dstRes = ((ResourceNode) chToRes.getDestination()).getOutSideResource();
-								String dstResName = getComponentName(dstRes.getResourceHierarchy());
+								String dstResName = null;
+								if (generatesComponent(dstRes.getResourceHierarchy())) {
+									dstResName = getComponentName(dstRes.getResourceHierarchy());
+								} else {
+									dstResName = getComponentName(dstRes.getResourceHierarchy().getParent());
+								}
 								depends.add(dstRes);
-								type.addField(new FieldDeclaration(new Type(dstResName, dstResName), dstRes.getResourceName()));
-								constructor.addParameter(new VariableDeclaration(new Type(dstResName, dstResName), dstRes.getResourceName()));
+								type.addField(new FieldDeclaration(new Type(dstResName, dstResName), toVariableName(dstResName)));
+								constructor.addParameter(new VariableDeclaration(new Type(dstResName, dstResName), toVariableName(dstResName)));
 								block.addStatement("this." + toVariableName(dstResName) + " = " + toVariableName(dstResName) + ";");
 							}
 						}
@@ -238,12 +259,39 @@
 						for (Edge resToCh: chToRes.getSource().getInEdges()) {
 							DataFlowEdge re = (DataFlowEdge) resToCh;
 							ResourcePath srcRes = ((ResourceNode) re.getSource()).getOutSideResource();
-							String srcResName = getComponentName(srcRes.getResourceHierarchy());
-							if (((PushPullAttribute) re.getAttribute()).getOptions().get(0) != PushPullValue.PUSH) {
+							DataTransferChannel ch = ((ChannelNode) re.getDestination()).getChannel();
+							// Check if the input and output resources are outside of the channel scope.
+							boolean outsideInputResource = false;
+							boolean outsideOutputResource = false;
+							if (ch.getAllSelectors().size() > 0) {
+								Set<Expression> params = new HashSet<>();
+								for (Selector s: ch.getAllSelectors()) {
+									params.add(s.getExpression());
+								}
+								for (ChannelMember cm: ch.getInputChannelMembers()) {
+									if (cm.getResource().getResourceHierarchy().equals(srcRes.getResourceHierarchy()) && !params.containsAll(cm.getResource().getPathParams())) {
+										outsideInputResource = true;	// Regarded as pull transfer.
+										break;
+									}
+								}
+								for (ChannelMember cm: ch.getOutputChannelMembers()) {
+									if (cm.getResource().getResourceHierarchy().equals(rn.getOutSideResource().getResourceHierarchy()) && !params.containsAll(cm.getResource().getPathParams())) {
+										outsideOutputResource = true;	// Regarded as push transfer.
+										break;
+									}
+								}
+							}
+							String srcResName = null;
+							if (generatesComponent(srcRes.getResourceHierarchy())) {
+								srcResName = getComponentName(srcRes.getResourceHierarchy());
+							} else {
+								srcResName = getComponentName(srcRes.getResourceHierarchy().getParent());
+							}
+							if ((((PushPullAttribute) re.getAttribute()).getOptions().get(0) != PushPullValue.PUSH && !outsideOutputResource) || outsideInputResource) {
 								// Declare a field to refer to the source resource of pull transfer.
 								depends.add(srcRes);
-								type.addField(new FieldDeclaration(new Type(srcResName, srcResName), srcRes.getResourceName()));
-								constructor.addParameter(new VariableDeclaration(new Type(srcResName, srcResName), srcRes.getResourceName()));
+								type.addField(new FieldDeclaration(new Type(srcResName, srcResName), toVariableName(srcResName)));
+								constructor.addParameter(new VariableDeclaration(new Type(srcResName, srcResName), toVariableName(srcResName)));
 								block.addStatement("this." + toVariableName(srcResName) + " = " + toVariableName(srcResName) + ";");
 							} else {
 								// Declare an update method in the type of the destination resource.
@@ -297,15 +345,12 @@
 							for (ResourceHierarchy c: children) {
 								String childTypeName = getComponentName(c);
 								Type childType = null;
-								if ((c.getChildren() == null || c.getChildren().size() == 0) && c.getNumParameters() == 0) {
-									// The child does not have a component.
-									childType = c.getResourceStateType();
-								} else {
+								if (generatesComponent(c)) {
 									// The child has a component.
 									childType = new Type(childTypeName, childTypeName);
+									String fieldName = toVariableName(childTypeName);
+									type.addField(new FieldDeclaration(childType, fieldName, getInitializer(res)));							
 								}
-								String fieldName = toVariableName(childTypeName);
-								type.addField(new FieldDeclaration(childType, fieldName, getInitializer(res)));							
 							}
 						}
 					}
@@ -314,7 +359,7 @@
 				// Declare the getter methods to obtain the children resources.
 				for (ResourceNode child: rn.getChildren()) {
 					if (generatesComponent(child.getResourceHierarchy())) {
-						// A component is generated for the child.
+						// A component for the child is generated.
 						List<VariableDeclaration> params = new ArrayList<>();
 						int v = 1;
 						for (Selector param: child.getSelectors()) {
@@ -340,7 +385,83 @@
 				}
 			}
 			
-			// Declare the getter method to obtain the resource state in the component of each resource.
+			// Declare the state field and reference fields in the parent component.
+			if (type == null) {
+				// Declare reference fields for push/pull data transfer.
+				boolean noPullTransfer = true;
+				for (Edge resToCh : rn.getOutEdges()) {
+					DataFlowEdge re = (DataFlowEdge) resToCh;
+					DataTransferChannel ch = ((ChannelNode) re.getDestination()).getChannel();
+					for (Edge chToRes: re.getDestination().getOutEdges()) {
+						ResourcePath dstRes = ((ResourceNode) chToRes.getDestination()).getOutSideResource();
+						boolean outsideOutputResource = false;
+						if (ch.getAllSelectors().size() > 0) {
+							Set<Expression> params = new HashSet<>();
+							for (Selector s: ch.getAllSelectors()) {
+								params.add(s.getExpression());
+							}
+							for (ChannelMember cm: ch.getOutputChannelMembers()) {
+								if (cm.getResource().getResourceHierarchy().equals(dstRes.getResourceHierarchy()) && !params.containsAll(cm.getResource().getPathParams())) {
+									outsideOutputResource = true;	// Regarded as push transfer.
+									break;
+								}
+							}
+						}
+						if (outsideOutputResource) {
+							// Declare a field in the parent component to refer to the destination resource of push transfer.
+							String dstResName = null;
+							if (generatesComponent(dstRes.getResourceHierarchy())) {
+								dstResName = getComponentName(dstRes.getResourceHierarchy());
+							} else {
+								dstResName = getComponentName(dstRes.getResourceHierarchy().getParent());
+							}
+							FieldDeclaration refFieldForPush = new FieldDeclaration(new Type(dstResName, dstResName), toVariableName(dstResName));
+							fields.add(new AbstractMap.SimpleEntry(rn.getParent().getResourceHierarchy(), refFieldForPush));
+						}
+					}
+				}
+				for (Edge chToRes : rn.getInEdges()) {
+					for (Edge resToCh: chToRes.getSource().getInEdges()) {
+						DataFlowEdge re = (DataFlowEdge) resToCh;
+						ResourcePath srcRes = ((ResourceNode) re.getSource()).getOutSideResource();
+						DataTransferChannel ch = ((ChannelNode) re.getDestination()).getChannel();
+						boolean outsideInputResource = false;
+						if (ch.getAllSelectors().size() > 0) {
+							Set<Expression> params = new HashSet<>();
+							for (Selector s: ch.getAllSelectors()) {
+								params.add(s.getExpression());
+							}
+							for (ChannelMember cm: ch.getInputChannelMembers()) {
+								if (cm.getResource().getResourceHierarchy().equals(srcRes.getResourceHierarchy()) && !params.containsAll(cm.getResource().getPathParams())) {
+									outsideInputResource = true;	// Regarded as pull transfer.
+									break;
+								}
+							}
+						}
+						if (outsideInputResource) {
+							// Declare a field in the parent component to refer to the source resource of pull transfer.
+							String srcResName = null;
+							if (generatesComponent(srcRes.getResourceHierarchy())) {
+								srcResName = getComponentName(srcRes.getResourceHierarchy());
+							} else {
+								srcResName = getComponentName(srcRes.getResourceHierarchy().getParent());
+							}
+							FieldDeclaration refFieldForPull = new FieldDeclaration(new Type(srcResName, srcResName), toVariableName(srcResName));
+							fields.add(new AbstractMap.SimpleEntry(rn.getParent().getResourceHierarchy(), refFieldForPull));
+							noPullTransfer = false;
+						}
+					}
+				}
+				// Declare the state field in the parent component.
+				ResourceHierarchy res = rn.getOutSideResource().getResourceHierarchy();
+				if (((StoreAttribute) rn.getAttribute()).isStored() && noPullTransfer && res.getNumParameters() == 0) {
+					String resName = getComponentName(res);
+					FieldDeclaration stateField = new FieldDeclaration(res.getResourceStateType(), toVariableName(resName));
+					fields.add(new AbstractMap.SimpleEntry(rn.getParent().getResourceHierarchy(), stateField));
+				}
+			}
+			
+			// Declare the getter method in this component to obtain the resource state.
 			if (type != null) {
 				// A component is created for this resource.
 				MethodDeclaration stateGetter = new MethodDeclaration("getValue", getImplStateType(rn.getResourceHierarchy()));
@@ -370,7 +491,7 @@
 				getters.add(new AbstractMap.SimpleEntry(rn.getParent().getResourceHierarchy(), stateGetter));
 			}
 			
-			// Declare the getter accessor in the main type.
+			// Declare the accessor method in the main type to call the getter method.
 			MethodDeclaration accessor = null;
 			List<VariableDeclaration> mainGetterParams = new ArrayList<>();
 			int v = 1;
@@ -398,7 +519,7 @@
 			accessor.getBody().addStatement("return " + getState.toImplementation(new String[] {null}) + ";");
 			mainType.addMethod(accessor);
 			
-			// Declare the input method in each resource and the main component.
+			// Declare the input method in this component and the main component.
 			for (Channel ch : model.getIOChannels()) {
 				for (ChannelMember cm : ((DataTransferChannel) ch).getOutputChannelMembers()) {
 					if (rn.getInSideResources().contains(cm.getResource())) {
@@ -538,6 +659,11 @@
 		for (Map.Entry<ResourceHierarchy, MethodDeclaration> entry: inputs) {
 			resourceTypes.get(entry.getKey()).addMethod(entry.getValue());
 		}
+		
+		// Add leaf reference fields to the parent components.
+		for (Map.Entry<ResourceHierarchy, FieldDeclaration> entry: fields) {
+			resourceTypes.get(entry.getKey()).addField(entry.getValue());
+		}
 
 		// Declare the Pair class.
 		boolean isCreatedPair = false;
diff --git a/AlgebraicDataflowArchitectureModel/src/generators/JerseyCodeGenerator.java b/AlgebraicDataflowArchitectureModel/src/generators/JerseyCodeGenerator.java
index 855de3b..0062119 100644
--- a/AlgebraicDataflowArchitectureModel/src/generators/JerseyCodeGenerator.java
+++ b/AlgebraicDataflowArchitectureModel/src/generators/JerseyCodeGenerator.java
@@ -53,6 +53,7 @@
 public class JerseyCodeGenerator {
 	public static final Type typeVoid = new Type("Void", "void");
 	public static final Type typeClient = new Type("Client", "Client");
+	public static boolean differentTreesAsDifferentServices = true;
 	private static String defaultMainTypeName = "Main";
 	static String mainTypeName = defaultMainTypeName;
 
@@ -131,6 +132,7 @@
 		Map<ResourceHierarchy, TypeDeclaration> resourceTypes = new HashMap<>();
 		List<Map.Entry<ResourceHierarchy, MethodDeclaration>> getters = new ArrayList<>();
 		List<Map.Entry<ResourceHierarchy, MethodDeclaration>> inputs = new ArrayList<>();
+		List<Map.Entry<ResourceHierarchy, FieldDeclaration>> fields = new ArrayList<>();
 		Map<ResourceHierarchy, MethodDeclaration> getterAccessors = new HashMap<>();
 		Map<ResourceHierarchy, MethodDeclaration> inputAccessors = new HashMap<>();
 
@@ -164,30 +166,94 @@
 						cu.addImport(new ImportDeclaration("com.fasterxml.jackson.core.JsonProcessingException"));
 					}
 					codes.add(cu);
-				}
-				
-				// Declare a client field and update methods from other resources.
-				if (rn.getResourceHierarchy().getParent() == null) {
-					// For a root resource
+					
+					// Declare a client field and update methods from other resources.
 					boolean bDeclareClientField = false;
 					for (Edge resToCh: rn.getOutEdges()) {
 						DataFlowEdge re = (DataFlowEdge) resToCh;
-						if (!bDeclareClientField && ((PushPullAttribute) re.getAttribute()).getOptions().get(0) == PushPullValue.PUSH) {
-							// Declare a client field to connect to the destination resource of push transfer.
-							type.addField(new FieldDeclaration(typeClient, "client", "ClientBuilder.newClient()"));
-							bDeclareClientField = true;
+						DataTransferChannel ch = ((ChannelNode) re.getDestination()).getChannel();
+						// Check if the input resource is outside of the channel scope.
+						boolean outsideInputResource = false;
+						if (ch.getAllSelectors().size() > 0) {
+							Set<Expression> params = new HashSet<>();
+							for (Selector s: ch.getAllSelectors()) {
+								params.add(s.getExpression());
+							}
+							for (ChannelMember cm: ch.getInputChannelMembers()) {
+								if (cm.getResource().getResourceHierarchy().equals(rn.getResourceHierarchy()) && !params.containsAll(cm.getResource().getPathParams())) {
+									outsideInputResource = true;	// Regarded as pull transfer.
+									break;
+								}
+							}
+						}
+						if (!bDeclareClientField && ((PushPullAttribute) re.getAttribute()).getOptions().get(0) == PushPullValue.PUSH && !outsideInputResource) {
+							for (ChannelMember cm: ch.getOutputChannelMembers()) {
+								ResourcePath dstRes = cm.getResource();
+								String dstResName = null;
+								if (generatesComponent(dstRes.getResourceHierarchy())) {
+									dstResName = getComponentName(dstRes.getResourceHierarchy());
+								} else {
+									dstResName = getComponentName(dstRes.getResourceHierarchy().getParent());
+								}
+								if (rn.getOutSideResource().getCommonPrefix(dstRes) == null && differentTreesAsDifferentServices) {
+									// Inter-service
+									if (bDeclareClientField) {
+										// Declare a client field to connect to the destination resource of push transfer.
+										type.addField(new FieldDeclaration(typeClient, "client", "ClientBuilder.newClient()"));
+										bDeclareClientField = true;
+									}
+								} else {
+									// Inner-service
+									// Declare a field to directly refer to the destination resource of push transfer.
+									type.addField(new FieldDeclaration(new Type(dstResName, dstResName), toVariableName(dstResName)));
+								}
+							}
 						}
 					}
 					for (Edge chToRes : rn.getInEdges()) {
 						for (Edge resToCh: chToRes.getSource().getInEdges()) {
 							DataFlowEdge re = (DataFlowEdge) resToCh;
 							ResourcePath srcRes = ((ResourceNode) re.getSource()).getOutSideResource();
-							String srcResName = getComponentName(srcRes.getResourceHierarchy());
-							if (((PushPullAttribute) re.getAttribute()).getOptions().get(0) != PushPullValue.PUSH) {
-								if (!bDeclareClientField) {
-									// Declare a client field to connect to the source resource of pull transfer.
-									type.addField(new FieldDeclaration(typeClient, "client", "ClientBuilder.newClient()"));
-									bDeclareClientField = true;
+							DataTransferChannel ch = ((ChannelNode) re.getDestination()).getChannel();
+							// Check if the input and output resources are outside of the channel scope.
+							boolean outsideInputResource = false;
+							boolean outsideOutputResource = false;
+							if (ch.getAllSelectors().size() > 0) {
+								Set<Expression> params = new HashSet<>();
+								for (Selector s: ch.getAllSelectors()) {
+									params.add(s.getExpression());
+								}
+								for (ChannelMember cm: ch.getInputChannelMembers()) {
+									if (cm.getResource().getResourceHierarchy().equals(srcRes.getResourceHierarchy()) && !params.containsAll(cm.getResource().getPathParams())) {
+										outsideInputResource = true;	// Regarded as pull transfer.
+										break;
+									}
+								}
+								for (ChannelMember cm: ch.getOutputChannelMembers()) {
+									if (cm.getResource().getResourceHierarchy().equals(rn.getOutSideResource().getResourceHierarchy()) && !params.containsAll(cm.getResource().getPathParams())) {
+										outsideOutputResource = true;	// Regarded as push transfer.
+										break;
+									}
+								}
+							}
+							String srcResName = null;
+							if (generatesComponent(srcRes.getResourceHierarchy())) {
+								srcResName = getComponentName(srcRes.getResourceHierarchy());
+							} else {
+								srcResName = getComponentName(srcRes.getResourceHierarchy().getParent());
+							}
+							if ((((PushPullAttribute) re.getAttribute()).getOptions().get(0) != PushPullValue.PUSH && !outsideOutputResource) || outsideInputResource) {
+								if (rn.getOutSideResource().getCommonPrefix(srcRes) == null && differentTreesAsDifferentServices) {
+									// Inter-service
+									if (!bDeclareClientField) {
+										// Declare a client field to connect to the source resource of pull transfer.
+										type.addField(new FieldDeclaration(typeClient, "client", "ClientBuilder.newClient()"));
+										bDeclareClientField = true;
+									}
+								} else {
+									// Inner-service
+									// Declare a field to directly refer to the source resource of pull transfer.
+									type.addField(new FieldDeclaration(new Type(srcResName, srcResName), toVariableName(srcResName)));
 								}
 							} else {
 								// Declare an update method in the type of the destination resource.
@@ -262,15 +328,12 @@
 							for (ResourceHierarchy c: children) {
 								String childTypeName = getComponentName(c);
 								Type childType = null;
-								if ((c.getChildren() == null || c.getChildren().size() == 0) && c.getNumParameters() == 0) {
-									// The child does not have a component.
-									childType = c.getResourceStateType();
-								} else {
+								if (generatesComponent(c)) {
 									// The child has a component.
 									childType = new Type(childTypeName, childTypeName);
+									String fieldName = toVariableName(childTypeName);
+									type.addField(new FieldDeclaration(childType, fieldName, getInitializer(res)));							
 								}
-								String fieldName = toVariableName(childTypeName);
-								type.addField(new FieldDeclaration(childType, fieldName, getInitializer(res)));							
 							}
 						}
 					}
@@ -305,6 +368,107 @@
 				}
 			}
 			
+			// Declare the state field and reference fields in the parent component.
+			if (type == null) {
+				// Declare reference fields for push/pull data transfer.
+				boolean bDeclareClientField = false;
+				boolean noPullTransfer = true;
+				for (Edge resToCh : rn.getOutEdges()) {
+					DataFlowEdge re = (DataFlowEdge) resToCh;
+					DataTransferChannel ch = ((ChannelNode) re.getDestination()).getChannel();
+					for (Edge chToRes: re.getDestination().getOutEdges()) {
+						ResourcePath dstRes = ((ResourceNode) chToRes.getDestination()).getOutSideResource();
+						boolean outsideOutputResource = false;
+						if (ch.getAllSelectors().size() > 0) {
+							Set<Expression> params = new HashSet<>();
+							for (Selector s: ch.getAllSelectors()) {
+								params.add(s.getExpression());
+							}
+							for (ChannelMember cm: ch.getOutputChannelMembers()) {
+								if (cm.getResource().getResourceHierarchy().equals(dstRes.getResourceHierarchy()) && !params.containsAll(cm.getResource().getPathParams())) {
+									outsideOutputResource = true;	// Regarded as push transfer.
+									break;
+								}
+							}
+						}
+						if (outsideOutputResource) {
+							// Declare a field in the parent component to refer to the destination resource of push transfer.
+							String dstResName = null;
+							if (generatesComponent(dstRes.getResourceHierarchy())) {
+								dstResName = getComponentName(dstRes.getResourceHierarchy());
+							} else {
+								dstResName = getComponentName(dstRes.getResourceHierarchy().getParent());
+							}
+							if (rn.getOutSideResource().getCommonPrefix(dstRes) == null && differentTreesAsDifferentServices) {
+								// Inter-service
+								if (!bDeclareClientField) {
+									// Declare a client field to connect to the destination resource of push transfer.
+									FieldDeclaration clientField = new FieldDeclaration(typeClient, "client", "ClientBuilder.newClient()");
+									fields.add(new AbstractMap.SimpleEntry(rn.getParent().getResourceHierarchy(), clientField));
+									bDeclareClientField = true;
+								}
+							} else {
+								// Inner-service
+								// Declare a field to directly refer to the destination resource of push transfer.
+								FieldDeclaration refFieldForPush = new FieldDeclaration(new Type(dstResName, dstResName), toVariableName(dstResName));
+								fields.add(new AbstractMap.SimpleEntry(rn.getParent().getResourceHierarchy(), refFieldForPush));
+							}
+						}
+					}
+				}
+				for (Edge chToRes : rn.getInEdges()) {
+					for (Edge resToCh: chToRes.getSource().getInEdges()) {
+						DataFlowEdge re = (DataFlowEdge) resToCh;
+						ResourcePath srcRes = ((ResourceNode) re.getSource()).getOutSideResource();
+						DataTransferChannel ch = ((ChannelNode) re.getDestination()).getChannel();
+						boolean outsideInputResource = false;
+						if (ch.getAllSelectors().size() > 0) {
+							Set<Expression> params = new HashSet<>();
+							for (Selector s: ch.getAllSelectors()) {
+								params.add(s.getExpression());
+							}
+							for (ChannelMember cm: ch.getInputChannelMembers()) {
+								if (cm.getResource().getResourceHierarchy().equals(srcRes.getResourceHierarchy()) && !params.containsAll(cm.getResource().getPathParams())) {
+									outsideInputResource = true;	// Regarded as pull transfer.
+									break;
+								}
+							}
+						}
+						if (outsideInputResource) {
+							// Declare a field in the parent component to refer to the source resource of pull transfer.
+							String srcResName = null;
+							if (generatesComponent(srcRes.getResourceHierarchy())) {
+								srcResName = getComponentName(srcRes.getResourceHierarchy());
+							} else {
+								srcResName = getComponentName(srcRes.getResourceHierarchy().getParent());
+							}
+							if (rn.getOutSideResource().getCommonPrefix(srcRes) == null && differentTreesAsDifferentServices) {
+								// Inter-service
+								if (!bDeclareClientField) {
+									// Declare a client field to connect to the source resource of pull transfer.
+									FieldDeclaration clientField = new FieldDeclaration(typeClient, "client", "ClientBuilder.newClient()");
+									fields.add(new AbstractMap.SimpleEntry(rn.getParent().getResourceHierarchy(), clientField));
+									bDeclareClientField = true;
+								}
+							} else {
+								// Inner-service								
+								// Declare a field to directly refer to the source resource of pull transfer.
+								FieldDeclaration refFieldForPull = new FieldDeclaration(new Type(srcResName, srcResName), toVariableName(srcResName));
+								fields.add(new AbstractMap.SimpleEntry(rn.getParent().getResourceHierarchy(), refFieldForPull));
+								noPullTransfer = false;
+							}
+						}
+					}
+				}
+				// Declare the state field in the parent component.
+				ResourceHierarchy res = rn.getOutSideResource().getResourceHierarchy();
+				if (((StoreAttribute) rn.getAttribute()).isStored() && noPullTransfer && res.getNumParameters() == 0) {
+					String resName = getComponentName(res);
+					FieldDeclaration stateField = new FieldDeclaration(res.getResourceStateType(), toVariableName(resName));
+					fields.add(new AbstractMap.SimpleEntry(rn.getParent().getResourceHierarchy(), stateField));
+				}
+			}
+			
 			// Declare the getter method to obtain the resource state in the component of each resource.
 			if (type != null) {
 				// A component is created for this resource.
@@ -345,27 +509,12 @@
 				// For a non-root resource
 				MethodDeclaration getterAccessor = null;
 				List<VariableDeclaration> mainGetterParams = new ArrayList<>();
-				String resourcePath = "\"";
-				int v = 1;
-				for (Selector pathParam: rn.getAllSelectors()) {
-					if (pathParam.getExpression() instanceof Variable) {
-						Variable var = (Variable) pathParam.getExpression();
-						String paramName = var.getName();
-						VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
-						param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
-						mainGetterParams.add(param);								
-						resourcePath += "/{" + paramName + "}";
-					} else if (pathParam.getExpression() instanceof Term) {
-						Term var = (Term) pathParam.getExpression();
-						String paramName = "v" + v;
-						VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
-						param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
-						mainGetterParams.add(param);								
-						resourcePath += "/{" + paramName + "}";
-					}
-					v++;
+				String resourcePath = getGetterResourcePathAndPathParams(rn, mainGetterParams);
+				if (resourcePath.indexOf('/') > 0) {
+					resourcePath = "\"" + resourcePath.substring(resourcePath.indexOf('/')) + "\"";
+				} else {
+					resourcePath = "\"" + resourcePath + "\"";
 				}
-				resourcePath += "\"";
 				if (mainGetterParams.size() > 0) {
 					getterAccessor = new MethodDeclaration("get" + getComponentName(rn.getResourceHierarchy()) + "Value",
 														false,
@@ -381,7 +530,7 @@
 				
 				getterAccessor.addAnnotation(new Annotation("Produces", "MediaType.APPLICATION_JSON"));
 				getterAccessor.addAnnotation(new Annotation("GET"));
-				if (rn.getSelectors().size() > 0) {
+				if (rn.getAllSelectors().size() > 0) {
 					getterAccessor.addAnnotation(new Annotation("Path", resourcePath));
 				}
 				getterAccessors.put(rn.getResourceHierarchy(), getterAccessor);
@@ -396,51 +545,12 @@
 							// In each resource.
 							ArrayList<VariableDeclaration> resInputParams = new ArrayList<>();
 							ArrayList<VariableDeclaration> rootInputParams = new ArrayList<>();
-							String resourcePath = "\"";
-							int v = 1;
-							for (Selector selector: rn.getSelectors()) {
-								if (selector.getExpression() instanceof Variable) {
-									Variable var = (Variable) selector.getExpression();
-									String paramName = var.getName();
-									VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
-									resInputParams.add(param);
-									param = new VariableDeclaration(var.getType(), paramName);
-									param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
-									rootInputParams.add(param);
-									resourcePath += "/{" + paramName + "}";
-								} else if (selector.getExpression() instanceof Term) {
-									Term var = (Term) selector.getExpression();
-									String paramName = "v" + v;
-									VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
-									resInputParams.add(param);
-									param = new VariableDeclaration(var.getType(), paramName);
-									param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
-									rootInputParams.add(param);
-									resourcePath += "/{" + paramName + "}";
-								}
-								v++;
+							String resourcePath = getInputMethodResourcePathaAndPathParams(rn, resInputParams, rootInputParams);
+							if (resourcePath.indexOf('/') > 0) {
+								resourcePath = "\"" + resourcePath.substring(resourcePath.indexOf('/')) + "\"";
+							} else {
+								resourcePath = "\"" + resourcePath + "\"";
 							}
-							if (rn.getParent() != null) {
-								for (Selector selector: rn.getParent().getAllSelectors()) {
-									if (selector.getExpression() instanceof Variable) {
-										Variable var = (Variable) selector.getExpression();
-										String paramName = var.getName();
-										VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
-										param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
-										rootInputParams.add(param);
-										resourcePath += "/{" + paramName + "}";
-									} else if (selector.getExpression() instanceof Term) {
-										Term var = (Term) selector.getExpression();
-										String paramName = "v" + v;
-										VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
-										param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
-										rootInputParams.add(param);
-										resourcePath += "/{" + paramName + "}";
-									}
-									v++;
-								}
-							}
-							resourcePath += "\"";
 							for (Variable var: message.getVariables().values()) {
 								String paramName = var.getName();
 								VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
@@ -506,27 +616,12 @@
 							
 							// For the root resource.
 							ArrayList<VariableDeclaration> rootInputParams = new ArrayList<>();
-							String resourcePath = "\"";
-							v = 1;
-							for (Selector selector: rn.getAllSelectors()) {
-								if (selector.getExpression() instanceof Variable) {
-									Variable var = (Variable) selector.getExpression();
-									String paramName = var.getName();
-									VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
-									param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
-									rootInputParams.add(param);
-									resourcePath += "/{" + paramName + "}";
-								} else if (selector.getExpression() instanceof Term) {
-									Term var = (Term) selector.getExpression();
-									String paramName = "v" + v;
-									VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
-									param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
-									rootInputParams.add(param);
-									resourcePath += "/{" + paramName + "}";
-								}
-								v++;
+							String resourcePath = getGetterResourcePathAndPathParams(rn, rootInputParams);
+							if (resourcePath.indexOf('/') > 0) {
+								resourcePath = "\"" + resourcePath.substring(resourcePath.indexOf('/')) + "\"";
+							} else {
+								resourcePath = "\"" + resourcePath + "\"";
 							}
-							resourcePath += "\"";
 							String str = ((Term) cm.getStateTransition().getMessageExpression()).getSymbol().getImplName();
 							MethodDeclaration inputAccessor = new MethodDeclaration(str, false, typeVoid, rootInputParams);
 							if (cm.getStateTransition().isRightUnary()) {
@@ -554,6 +649,11 @@
 			resourceTypes.get(entry.getKey()).addMethod(entry.getValue());
 		}
 		
+		// Add leaf reference fields to the parent components.
+		for (Map.Entry<ResourceHierarchy, FieldDeclaration> entry: fields) {
+			resourceTypes.get(entry.getKey()).addField(entry.getValue());
+		}
+		
 		// Add accessors.
 		for (ResourceHierarchy rootRes: model.getResourceHierarchies()) {
 			if (rootRes.getParent() == null) {
@@ -619,6 +719,79 @@
 		return codes;
 	}
 
+	private static String getGetterResourcePathAndPathParams(ResourceNode rn, List<VariableDeclaration> pathParams) {
+		int v = 1;
+		List<String> params = new ArrayList<>();
+		for (Selector selector: rn.getAllSelectors()) {
+			if (selector.getExpression() instanceof Variable) {
+				Variable var = (Variable) selector.getExpression();
+				String paramName = var.getName();
+				params.add(paramName);
+				VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
+				param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
+				pathParams.add(param);
+			} else if (selector.getExpression() instanceof Term) {
+				Term var = (Term) selector.getExpression();
+				String paramName = "v" + v;
+				params.add(paramName);
+				VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
+				param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
+				pathParams.add(param);
+			}
+			v++;
+		}
+		return rn.getResourceHierarchy().toResourcePath(params);
+	}
+
+	private static String getInputMethodResourcePathaAndPathParams(ResourceNode rn, ArrayList<VariableDeclaration> resInputParams,
+			ArrayList<VariableDeclaration> rootInputParams) {
+		int v = 1;
+		List<String> params = new ArrayList<>();
+		for (Selector selector: rn.getSelectors()) {
+			if (selector.getExpression() instanceof Variable) {
+				Variable var = (Variable) selector.getExpression();
+				String paramName = var.getName();
+				params.add(paramName);
+				VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
+				resInputParams.add(param);
+				param = new VariableDeclaration(var.getType(), paramName);
+				param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
+				rootInputParams.add(param);
+			} else if (selector.getExpression() instanceof Term) {
+				Term var = (Term) selector.getExpression();
+				String paramName = "v" + v;
+				params.add(paramName);
+				VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
+				resInputParams.add(param);
+				param = new VariableDeclaration(var.getType(), paramName);
+				param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
+				rootInputParams.add(param);
+			}
+			v++;
+		}
+		if (rn.getParent() != null) {
+			for (Selector selector: rn.getParent().getAllSelectors()) {
+				if (selector.getExpression() instanceof Variable) {
+					Variable var = (Variable) selector.getExpression();
+					String paramName = var.getName();
+					params.add(paramName);
+					VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
+					param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
+					rootInputParams.add(param);
+				} else if (selector.getExpression() instanceof Term) {
+					Term var = (Term) selector.getExpression();
+					String paramName = "v" + v;
+					params.add(paramName);
+					VariableDeclaration param = new VariableDeclaration(var.getType(), paramName);
+					param.addAnnotation(new Annotation("PathParam", "\"" + paramName + "\""));
+					rootInputParams.add(param);
+				}
+				v++;
+			}
+		}
+		return rn.getResourceHierarchy().toResourcePath(params);
+	}
+
 	private static String getInitializer(ResourcePath resId) {
 		Type stateType = resId.getResourceStateType();
 		String initializer = null;
diff --git a/AlgebraicDataflowArchitectureModel/src/models/algebra/Term.java b/AlgebraicDataflowArchitectureModel/src/models/algebra/Term.java
index 81b24ed..a0f34eb 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/algebra/Term.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/algebra/Term.java
@@ -325,7 +325,7 @@
 				return "(" + children.get(implParamOrder[0]).toImplementation(sideEffects) + symbol.toImplementation() + children.get(implParamOrder[1]).toImplementation(sideEffects) + ")";				
 			}
 		}
-		if (getArity() >= 1 && symbol.isImplMethod()) {
+		if ((getArity() >= 1 || getArity() == -1) && symbol.isImplMethod()) {
 			if (implParamOrder == null) {
 				String exp = null;
 				if (children.get(0) != null) {
diff --git a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/ResourceHierarchy.java b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/ResourceHierarchy.java
index 0994c0a..be87686 100644
--- a/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/ResourceHierarchy.java
+++ b/AlgebraicDataflowArchitectureModel/src/models/dataConstraintModel/ResourceHierarchy.java
@@ -228,4 +228,15 @@
 			return parent.toString(pathParams) + ".{" + lastParam +"}";
 		}
 	}
+	
+	public String toResourcePath(List<String> pathParams) {
+		if (parent == null) return resourceName;
+		if (resourceName != null) {
+			return parent.toResourcePath(pathParams) + "/" + resourceName;
+		} else {
+			String lastParam = pathParams.get(pathParams.size() - 1);
+			pathParams = pathParams.subList(0, pathParams.size() - 1);
+			return parent.toResourcePath(pathParams) + "/{" + lastParam +"}";
+		}
+	}
 }
\ No newline at end of file