Convert refids to an aspect based implementation

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@272721 13f79535-47bb-0310-9956-ffa450edef68

proposal/mutant/src/java/antcore/org/apache/ant/antcore/execution/ComponentManager.java

@@ -440,21 +440,40 @@ public class ComponentManager implements ComponentService {
      * @exception ExecutionException if there is a problem creating or
      *      configuring the component
      */
-    protected Object createComponent(String componentName, BuildElement model)
+    private Object createComponent(String componentName, BuildElement model)
          throws ExecutionException {
 
-        ImportInfo importInfo = getImport(componentName);
-        if (importInfo == null) {
-            throw new ExecutionException("There is no definition of the <"
-                 + componentName + "> component");
+        Object component = null;
+        if (model != null) {             
+            for (Iterator i = aspects.iterator(); i.hasNext();) {
+                Aspect aspect = (Aspect) i.next();
+                component = aspect.preCreateComponent(component, model);
+            }
         }
-        String className = importInfo.getClassName();
-
-        ComponentLibrary componentLibrary
-             = importInfo.getComponentLibrary();
-
-        return createComponentFromDef(componentName, componentLibrary,
-            importInfo.getDefinition(), model);
+        
+        if (component == null) {
+            ImportInfo importInfo = getImport(componentName);
+            if (importInfo == null) {
+                throw new ExecutionException("There is no definition of the <"
+                + componentName + "> component");
+            }
+            String className = importInfo.getClassName();
+            
+            ComponentLibrary componentLibrary
+            = importInfo.getComponentLibrary();
+            
+            component = createComponentFromDef(componentName, componentLibrary,
+                importInfo.getDefinition(), model);
+        }
+        
+        if (model != null) {
+            for (Iterator i = aspects.iterator(); i.hasNext();) {
+                Aspect aspect = (Aspect) i.next();
+                component = aspect.postCreateComponent(component, model);
+            }
+        }
+        
+        return component;
     }
 
     /**
@@ -672,36 +691,12 @@ public class ComponentManager implements ComponentService {
         // is there a polymorph indicator - look in Ant aspects
         String typeName 
             = model.getAspectAttributeValue(Constants.ANT_ASPECT, "type");
-        String refId 
-            = model.getAspectAttributeValue(Constants.ANT_ASPECT, "refid");
-        if (refId != null && typeName != null) {
-            throw new ExecutionException("Only one of " + Constants.ANT_ASPECT
-                 + ":type and " + Constants.ANT_ASPECT
-                 + ":refid may be specified at a time", model.getLocation());
-        }
 
         Object typeInstance = null;
         if (typeName != null) {
             // the build file has specified the actual type of the element.
             // we need to look up that type and use it
             typeInstance = createComponent(typeName, model);
-        } else if (refId != null) {
-            // We have a reference to an existing instance. Need to check if
-            // it is compatible with the type expected by the nested element's
-            // adder method
-            typeInstance = frame.getDataValue(refId);
-            if (model.getAttributeNames().hasNext() ||
-                model.getNestedElements().hasNext() ||
-                model.getText().length() != 0) {
-                throw new ExecutionException("Element <" + nestedElementName
-                     + "> is defined by reference and hence may not specify "
-                     + "any attributes, nested elements or content",
-                    model.getLocation());
-            }
-            if (typeInstance == null) {
-                throw new ExecutionException("The given ant:refid value '"
-                     + refId + "' is not defined", model.getLocation());
-            }
         } else if (nestedType != null) {
             // We need to create an instance of the class expected by the nested
             // element's adder method if that is possible
@@ -723,17 +718,9 @@ public class ComponentManager implements ComponentService {
         // is the typeInstance compatible with the type expected
         // by the element's add method
         if (!nestedType.isInstance(typeInstance)) {
-            if (refId != null) {
-                throw new ExecutionException("The value specified by refId "
-                     + refId + " is not compatible with the <"
-                     + nestedElementName + "> nested element",
-                    model.getLocation());
-            } else if (typeName != null) {
-                throw new ExecutionException("The type "
-                     + typeName + " is not compatible with the <"
-                     + nestedElementName + "> nested element",
-                    model.getLocation());
-            }
+            throw new ExecutionException("The type "
+                + typeName + " is not compatible with the <"
+                + nestedElementName + "> nested element", model.getLocation());
         }
         setter.addElement(element, nestedElementName, typeInstance);
     }
@@ -781,23 +768,28 @@ public class ComponentManager implements ComponentService {
      *
      * @param object the object to be configured.
      * @param attributeValues a map containing named attribute values.
-     *
+     * @param ignoreUnsupported if this is true, attribute names for which no
+     *                          setter method exists are ignored.
      * @exception ExecutionException if the object does not support an
      *            attribute in the map.
      */
-    public void configureAttributes(Object object, Map attributeValues)
+    public void configureAttributes(Object object, Map attributeValues,
+                                    boolean ignoreUnsupported)
          throws ExecutionException {
         Setter setter = getSetter(object.getClass());
         for (Iterator i = attributeValues.keySet().iterator(); i.hasNext();) {
             String attributeName = (String) i.next();
             String attributeValue = (String) attributeValues.get(attributeName);
             if (!setter.supportsAttribute(attributeName)) {
-                throw new ExecutionException(object.getClass().getName()
-                     + " does not support the \"" + attributeName
-                     + "\" attribute");
+                if (!ignoreUnsupported) {
+                    throw new ExecutionException(object.getClass().getName()
+                         + " does not support the \"" + attributeName
+                         + "\" attribute");
+                }
+            } else {
+                setter.setAttribute(object, attributeName,
+                    frame.replacePropertyRefs(attributeValue));
             }
-            setter.setAttribute(object, attributeName,
-                frame.replacePropertyRefs(attributeValue));
         }
     }
 

proposal/mutant/src/java/antcore/org/apache/ant/antcore/execution/Frame.java

@@ -868,6 +868,7 @@ public class Frame implements DemuxOutputReceiver {
      */
     protected void executeTask(Task task, AspectValueCollection aspectValues) 
          throws ExecutionException {
+
         List aspects = componentManager.getAspects();
         Map aspectContexts = new HashMap();
         for (Iterator i = aspects.iterator(); i.hasNext();) {
@@ -897,6 +898,7 @@ public class Frame implements DemuxOutputReceiver {
         }
 
         // Now call back the aspects that registered interest
+
         Set activeAspects = aspectContexts.keySet();
         for (Iterator i = activeAspects.iterator(); i.hasNext();) {
             Aspect aspect = (Aspect) i.next();
@@ -932,18 +934,8 @@ public class Frame implements DemuxOutputReceiver {
             BuildElement model = (BuildElement) taskIterator.next();
 
             // what sort of element is this.
-            List aspects = componentManager.getAspects();
             try {
                 Object component = componentManager.createComponent(model);
-                for (Iterator i = aspects.iterator(); i.hasNext();) {
-                    Aspect aspect = (Aspect) i.next();
-                    Object replacement 
-                        = aspect.postCreateComponent(component, model);
-                    if (replacement != null) {
-                        component = replacement;
-                    }
-                }
-
                 if (component instanceof Task) {
                     execService.executeTask((Task) component);
                 } 

proposal/mutant/src/java/antlibs/system/org/apache/ant/antlib/system/AntAspect.java

@@ -91,6 +91,41 @@ public class AntAspect extends AbstractAspect {
             = (ComponentService) context.getCoreService(ComponentService.class);
     }
     
+
+    /**
+     * This join point is activated before a component has been created.
+     * The aspect can return an object to be used rather than the core creating 
+     * the object. 
+     *
+     * @param component the component that has been created. This will be null
+     *                  unless another aspect has created the component
+     * @param model the Build model that applies to the component
+     *
+     * @return a component to use.
+     * @exception ExecutionException if the aspect cannot process the component.
+     */         
+    public Object preCreateComponent(Object component, BuildElement model)
+         throws ExecutionException {
+        String refId = model.getAspectAttributeValue(ANT_ASPECT, "refid");
+        if (refId != null) {
+            if (model.getAttributeNames().hasNext() ||
+                model.getNestedElements().hasNext() ||
+                model.getText().length() != 0) {
+                throw new ExecutionException("Element <" + model.getType()
+                     + "> is defined by reference and hence may not specify "
+                     + "any attributes, nested elements or content",
+                    model.getLocation());
+            }
+            Object referredComponent = dataService.getDataValue(refId);
+            if (referredComponent == null) {
+                throw new ExecutionException("The given ant:refid value '"
+                     + refId + "' is not defined", model.getLocation());
+            }
+            return referredComponent;
+        }             
+        return component;
+    }
+    
     /**
      * This join point is activated after a component has been created and
      * configured. If the aspect wishes, an object can be returned in place
@@ -111,7 +146,7 @@ public class AntAspect extends AbstractAspect {
             dataService.setMutableDataValue(typeId, component);
         }
         
-        return null;
+        return super.postCreateComponent(component, model);
     }
 
     /**
@@ -135,7 +170,8 @@ public class AntAspect extends AbstractAspect {
             return null;
         }
         
-        componentService.configureAttributes(aspectContext, antAspectValues);
+        componentService.configureAttributes(aspectContext, antAspectValues, 
+            true);
         if (aspectContext.isRequired()) {
             return aspectContext;
         }

proposal/mutant/src/java/common/org/apache/ant/common/antlib/AbstractAspect.java

@@ -88,7 +88,23 @@ public class AbstractAspect implements Aspect {
         return context;
     }
 
-         
+    /**
+     * This join point is activated before a component is to be created.
+     * The aspect can return an object to be used rather than the core creating 
+     * the object. 
+     *
+     * @param component the component that has been created. This will be null
+     *                  unless another aspect has created the component
+     * @param model the Build model that applies to the component
+     *
+     * @return a component to use.
+     * @exception ExecutionException if the aspect cannot process the component.
+     */         
+    public Object preCreateComponent(Object component, BuildElement model)
+         throws ExecutionException {
+        return component;
+    }
+
     /**
      * This join point is activated after a component has been created and
      * configured. If the aspect wishes, an object can be returned in place
@@ -103,7 +119,7 @@ public class AbstractAspect implements Aspect {
      */         
     public Object postCreateComponent(Object component, BuildElement model) 
          throws ExecutionException {
-        return null;
+        return component;
     }
 
     /**
@@ -111,8 +127,8 @@ public class AbstractAspect implements Aspect {
      *
      * @param task the task being executed.
      * @param aspectValues a collection of aspect attribute values for use 
-     *        during the task execution.
-     *
+     *        during the task execution - may be null if no aspect values are
+     *        provided.
      * @return an object which indicates that this aspect wishes to 
      * be notified after execution has been completed, in which case the obkect
      * is returned to provide the aspect its context. If this returns null

proposal/mutant/src/java/common/org/apache/ant/common/antlib/Aspect.java

@@ -75,6 +75,21 @@ public interface Aspect {
          throws ExecutionException;
 
          
+    /**
+     * This join point is activated before a component has been created.
+     * The aspect can return an object to be used rather than the core creating 
+     * the object. 
+     *
+     * @param component the component that has been created. This will be null
+     *                  unless another aspect has created the component
+     * @param model the Build model that applies to the component
+     *
+     * @return a component to use.
+     * @exception ExecutionException if the aspect cannot process the component.
+     */         
+    Object preCreateComponent(Object component, BuildElement model)
+        throws ExecutionException;
+
     /**
      * This join point is activated after a component has been created and
      * configured. If the aspect wishes, an object can be returned in place
@@ -83,8 +98,7 @@ public interface Aspect {
      * @param component the component that has been created.
      * @param model the Build model used to create the component.
      *
-     * @return a replacement for the component if desired. If null is returned
-     *         the current component is used.
+     * @return a component to use
      * @exception ExecutionException if the aspect cannot process the component.
      */         
     Object postCreateComponent(Object component, BuildElement model)

proposal/mutant/src/java/common/org/apache/ant/common/service/ComponentService.java

@@ -190,15 +190,17 @@ public interface ComponentService {
         throws ExecutionException;
         
     /**
-     * Configure an object with attribtes from the given map
+     * configure an object with attribtes from the given map
      *
      * @param object the object to be configured.
      * @param attributeValues a map containing named attribute values.
-     *
+     * @param ignoreUnsupported if this is true, attribute names for which no
+     *                          setter method exists are ignored.
      * @exception ExecutionException if the object does not support an
      *            attribute in the map.
      */
-    void configureAttributes(Object object, Map attributeValues)
+    void configureAttributes(Object object, Map attributeValues,
+                             boolean ignoreUnsupported)
          throws ExecutionException;
 }