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Posted to dev@pivot.apache.org by Roy Bailey <ro...@odinium.com> on 2009/10/02 22:36:32 UTC
Pivot auto-binding query
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to you under the Apache License,
* Version 2.0 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.pivot.wtkx;
import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.Proxy;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Collection;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import javax.script.Bindings;
import javax.script.Invocable;
import javax.script.ScriptContext;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;
import javax.script.SimpleBindings;
import javax.xml.stream.Location;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.XMLStreamException;
import org.apache.pivot.beans.BeanDictionary;
import org.apache.pivot.collections.ArrayList;
import org.apache.pivot.collections.Dictionary;
import org.apache.pivot.collections.HashMap;
import org.apache.pivot.collections.List;
import org.apache.pivot.collections.Sequence;
import org.apache.pivot.serialization.SerializationException;
import org.apache.pivot.serialization.Serializer;
import org.apache.pivot.util.ListenerList;
import org.apache.pivot.util.Resources;
import org.apache.pivot.util.ThreadUtilities;
import org.apache.pivot.util.Vote;
/**
* Loads an object hierarchy from an XML document.
*/
public class WTKXSerializer implements Serializer<Object>, Dictionary<String, Object> {
private class NamedObjectBindings implements Bindings {
@Override
public Object get(Object key) {
return namedObjects.get(key.toString());
}
@Override
public Object put(String key, Object value) {
return namedObjects.put(key, value);
}
@Override
public void putAll(Map<? extends String, ? extends Object> map) {
for (String key : map.keySet()) {
put(key, map.get(key));
}
}
@Override
public Object remove(Object key) {
return namedObjects.remove(key.toString());
}
@Override
public void clear() {
namedObjects.clear();
}
@Override
public boolean containsKey(Object key) {
return namedObjects.containsKey(key.toString());
}
@Override
public boolean containsValue(Object value) {
boolean contains = false;
for (String key : namedObjects) {
if (namedObjects.get(key).equals(value)) {
contains = true;
break;
}
}
return contains;
}
@Override
public boolean isEmpty() {
return namedObjects.isEmpty();
}
@Override
public Set<String> keySet() {
java.util.HashSet<String> keySet = new java.util.HashSet<String>();
for (String key : namedObjects) {
keySet.add(key);
}
return keySet;
}
@Override
public Set<Entry<String, Object>> entrySet() {
java.util.HashMap<String, Object> hashMap = new java.util.HashMap<String, Object>();
for (String key : namedObjects) {
hashMap.put(key, namedObjects.get(key));
}
return hashMap.entrySet();
}
@Override
public int size() {
return namedObjects.getCount();
}
@Override
public Collection<Object> values() {
java.util.ArrayList<Object> values = new java.util.ArrayList<Object>();
for (String key : namedObjects) {
values.add(namedObjects.get(key));
}
return values;
}
}
private static class Element {
public enum Type {
DEFINE,
INSTANCE,
INCLUDE,
SCRIPT,
READ_ONLY_PROPERTY,
WRITABLE_PROPERTY
}
public final Element parent;
public final Type type;
public final String tagName;
public final int lineNumber;
public final List<Attribute> attributes;
public Object value;
public Element(Element parent, Type type, String tagName, int lineNumber,
List<Attribute> attributes, Object value) {
this.parent = parent;
this.type = type;
this.tagName = tagName;
this.lineNumber = lineNumber;
this.attributes = attributes;
this.value = value;
}
}
private static class Attribute {
public final String namespaceURI;
public final String prefix;
public final String localName;
public final String value;
public Attribute(String namespaceURI, String prefix, String localName, String value) {
this.namespaceURI = namespaceURI;
this.prefix = prefix;
this.localName = localName;
this.value = value;
}
}
private static class WTKXSerializerListenerList extends ListenerList<WTKXSerializerListener>
implements WTKXSerializerListener {
@Override
public void includeLoaded(WTKXSerializer serializer, String id) {
for (WTKXSerializerListener listener : this) {
listener.includeLoaded(serializer, id);
}
}
@Override
public void allIncludesLoaded(WTKXSerializer serializer) {
for (WTKXSerializerListener listener : this) {
listener.allIncludesLoaded(serializer);
}
}
}
private URL location = null;
private Resources resources = null;
private HashMap<String, Object> initialBindings = new HashMap<String, Object>();
private Object root = null;
private HashMap<String, Object> namedObjects = new HashMap<String, Object>();
private HashMap<String, WTKXSerializer> includeSerializers = new HashMap<String, WTKXSerializer>();
private ScriptEngineManager scriptEngineManager = null;
private XMLInputFactory xmlInputFactory;
private Element element = null;
private WTKXSerializerListenerList wtkxSerializerListeners = new WTKXSerializerListenerList();
public static final char URL_PREFIX = '@';
public static final char RESOURCE_KEY_PREFIX = '%';
public static final char OBJECT_REFERENCE_PREFIX = '$';
public static final String WTKX_PREFIX = "wtkx";
public static final String ID_ATTRIBUTE = "id";
public static final String INCLUDE_TAG = "include";
public static final String INCLUDE_SRC_ATTRIBUTE = "src";
public static final String INCLUDE_RESOURCES_ATTRIBUTE = "resources";
public static final String INCLUDE_ASYNCHRONOUS_ATTRIBUTE = "asynchronous";
public static final String SCRIPT_TAG = "script";
public static final String SCRIPT_SRC_ATTRIBUTE = "src";
public static final String SCRIPT_LANGUAGE_ATTRIBUTE = "language";
public static final String DEFINE_TAG = "define";
public static final String MIME_TYPE = "application/wtkx";
public WTKXSerializer() {
this(null);
}
public WTKXSerializer(Resources resources) {
this.resources = resources;
xmlInputFactory = XMLInputFactory.newInstance();
xmlInputFactory.setProperty("javax.xml.stream.isCoalescing", true);
}
public Resources getResources() {
return resources;
}
public Object readObject(String resourceName)
throws IOException, SerializationException {
if (resourceName == null) {
throw new IllegalArgumentException("resourceName is null.");
}
ClassLoader classLoader = ThreadUtilities.getClassLoader();
URL location = classLoader.getResource(resourceName);
if (location == null) {
throw new SerializationException("Could not find resource named \""
+ resourceName + "\".");
}
return readObject(location);
}
public Object readObject(Object baseObject, String resourceName)
throws IOException, SerializationException {
if (baseObject == null) {
throw new IllegalArgumentException("baseObject is null.");
}
if (resourceName == null) {
throw new IllegalArgumentException("resourceName is null.");
}
return readObject(baseObject.getClass(), resourceName);
}
public Object readObject(Class<?> baseType, String resourceName)
throws IOException, SerializationException {
if (baseType == null) {
throw new IllegalArgumentException("baseType is null.");
}
if (resourceName == null) {
throw new IllegalArgumentException("resourceName is null.");
}
return readObject(baseType.getResource(resourceName));
}
public Object readObject(URL location)
throws IOException, SerializationException {
if (location == null) {
throw new IllegalArgumentException("location is null.");
}
this.location = location;
InputStream inputStream = new BufferedInputStream(location.openStream());
try {
return readObject(inputStream);
} finally {
inputStream.close();
}
}
@SuppressWarnings({"unchecked"})
@Override
public Object readObject(InputStream inputStream)
throws IOException, SerializationException {
if (inputStream == null) {
throw new IllegalArgumentException("inputStream is null.");
}
// Add the initial bindings
for (String key : initialBindings) {
namedObjects.put(key, initialBindings.get(key));
}
initialBindings.clear();
// Parse the XML stream
element = null;
try {
try {
XMLStreamReader reader = xmlInputFactory.createXMLStreamReader(inputStream);
while (reader.hasNext()) {
int event = reader.next();
switch (event) {
case XMLStreamConstants.CHARACTERS: {
if (!reader.isWhiteSpace()) {
String text = reader.getText();
if (text.length() > 0) {
switch (element.type) {
case INSTANCE: {
if (element.value instanceof Sequence) {
Sequence<Object> sequence = (Sequence<Object>)element.value;
try {
Method addMethod = sequence.getClass().getMethod("add",
new Class<?>[] {String.class});
addMethod.invoke(sequence, new Object[] {text});
} catch (NoSuchMethodException exception) {
throw new SerializationException("Text content cannot be added to "
+ sequence.getClass().getName() + ".", exception);
} catch (InvocationTargetException exception) {
throw new SerializationException(exception);
} catch (IllegalAccessException exception) {
throw new SerializationException(exception);
}
}
break;
}
case SCRIPT:
case WRITABLE_PROPERTY: {
element.value = text;
break;
}
default: {
throw new SerializationException("Unexpected characters in "
+ element.type + " element.");
}
}
}
}
break;
}
case XMLStreamConstants.START_ELEMENT: {
// Get element properties
String namespaceURI = reader.getNamespaceURI();
String prefix = reader.getPrefix();
String localName = reader.getLocalName();
// Build attribute list; these will be processed in the close tag
ArrayList<Attribute> attributes = new ArrayList<Attribute>();
for (int i = 0, n = reader.getAttributeCount(); i < n; i++) {
String attributeNamespaceURI = reader.getAttributeNamespace(i);
if (attributeNamespaceURI == null) {
attributeNamespaceURI = reader.getNamespaceURI("");
}
String attributePrefix = reader.getAttributePrefix(i);
String attributeLocalName = reader.getAttributeLocalName(i);
String attributeValue = reader.getAttributeValue(i);
attributes.add(new Attribute(attributeNamespaceURI,
attributePrefix, attributeLocalName, attributeValue));
}
// Determine the type and value of this element
Element.Type elementType = null;
Object value = null;
if (prefix != null
&& prefix.equals(WTKX_PREFIX)) {
// The element represents a WTKX operation
if (element == null) {
throw new SerializationException(prefix + ":" + localName
+ " is not a valid root element.");
}
if (localName.equals(INCLUDE_TAG)) {
elementType = Element.Type.INCLUDE;
} else if (localName.equals(SCRIPT_TAG)) {
elementType = Element.Type.SCRIPT;
} else if (localName.equals(DEFINE_TAG)) {
if (attributes.getLength() > 0) {
throw new SerializationException(WTKX_PREFIX + ":" + DEFINE_TAG
+ " cannot have attributes.");
}
elementType = Element.Type.DEFINE;
} else {
throw new SerializationException(prefix + ":" + localName
+ " is not a valid element.");
}
} else {
if (Character.isUpperCase(localName.charAt(0))) {
// The element represents a typed object
if (namespaceURI == null) {
throw new SerializationException("No XML namespace specified for "
+ localName + " tag.");
}
String className = namespaceURI + "." + localName.replace('.', '$');
try {
Class<?> type = Class.forName(className);
elementType = Element.Type.INSTANCE;
value = type.newInstance();
} catch (Exception exception) {
throw new SerializationException(exception);
}
} else {
// The element represents a property
if (element == null
|| element.type != Element.Type.INSTANCE) {
throw new SerializationException("Parent element must be a typed object.");
}
if (prefix != null
&& prefix.length() > 0) {
throw new SerializationException("Property elements cannot have a namespace prefix.");
}
BeanDictionary beanDictionary = new BeanDictionary(element.value);
if (beanDictionary.isReadOnly(localName)) {
elementType = Element.Type.READ_ONLY_PROPERTY;
value = beanDictionary.get(localName);
assert (value != null) : "Read-only properties cannot be null.";
if (attributes.getLength() > 0
&& !(value instanceof Dictionary<?, ?>)) {
throw new SerializationException("Only read-only dictionaries can have attributes.");
}
} else {
if (attributes.getLength() > 0) {
throw new SerializationException("Writable property elements cannot have attributes.");
}
elementType = Element.Type.WRITABLE_PROPERTY;
}
}
}
// Set the current element
String tagName = localName;
if (prefix != null
&& prefix.length() > 0) {
tagName = prefix + ":" + tagName;
}
Location xmlStreamLocation = reader.getLocation();
element = new Element(element, elementType, tagName, xmlStreamLocation.getLineNumber(),
attributes, value);
// If this is the root, set it
if (element.parent == null) {
root = element.value;
}
break;
}
case XMLStreamConstants.END_ELEMENT: {
String localName = reader.getLocalName();
switch (element.type) {
case INSTANCE:
case INCLUDE: {
String id = null;
ArrayList<Attribute> instancePropertyAttributes = new ArrayList<Attribute>();
ArrayList<Attribute> staticPropertyAttributes = new ArrayList<Attribute>();
if (element.type == Element.Type.INCLUDE) {
// Process attributes looking for wtkx:id, src, resources, asynchronous,
// and static property setters only
String src = null;
Resources resources = this.resources;
for (Attribute attribute : element.attributes) {
if (attribute.prefix != null
&& attribute.prefix.equals(WTKX_PREFIX)) {
if (attribute.localName.equals(ID_ATTRIBUTE)) {
id = attribute.value;
} else {
throw new SerializationException(WTKX_PREFIX + ":" + attribute.localName
+ " is not a valid attribute.");
}
} else {
if (attribute.localName.equals(INCLUDE_SRC_ATTRIBUTE)) {
src = attribute.value;
} else if (attribute.localName.equals(INCLUDE_RESOURCES_ATTRIBUTE)) {
resources = new Resources(resources, attribute.value);
} else if (attribute.localName.equals(INCLUDE_ASYNCHRONOUS_ATTRIBUTE)) {
// TODO
throw new UnsupportedOperationException("Asynchronous includes are not"
+ " yet supported.");
} else {
if (!Character.isUpperCase(attribute.localName.charAt(0))) {
throw new SerializationException("Instance property setters are not"
+ " supported for " + WTKX_PREFIX + ":" + INCLUDE_TAG
+ " " + " tag.");
}
staticPropertyAttributes.add(attribute);
}
}
}
if (src == null) {
throw new SerializationException(INCLUDE_SRC_ATTRIBUTE
+ " attribute is required for " + WTKX_PREFIX + ":" + INCLUDE_TAG
+ " tag.");
}
// Read the object
WTKXSerializer serializer = new WTKXSerializer(resources);
if (id != null) {
includeSerializers.put(id, serializer);
}
if (src.charAt(0) == '/') {
element.value = serializer.readObject(src.substring(1));
} else {
element.value = serializer.readObject(new URL(location, src));
}
if (id == null
&& !serializer.isEmpty()
&& serializer.scriptEngineManager == null) {
System.err.println("Include \"" + src + "\" defines unreachable objects.");
}
} else {
// Process attributes looking for wtkx:id and all property setters
for (Attribute attribute : element.attributes) {
if (attribute.prefix != null
&& attribute.prefix.equals(WTKX_PREFIX)) {
if (attribute.localName.equals(ID_ATTRIBUTE)) {
id = attribute.value;
} else {
throw new SerializationException(WTKX_PREFIX + ":" + attribute.localName
+ " is not a valid attribute.");
}
} else {
if (Character.isUpperCase(attribute.localName.charAt(0))) {
staticPropertyAttributes.add(attribute);
} else {
instancePropertyAttributes.add(attribute);
}
}
}
}
// If an ID was specified, add the value to the named object map
if (id != null) {
if (id.length() == 0) {
throw new IllegalArgumentException(WTKX_PREFIX + ":" + ID_ATTRIBUTE
+ " must not be null.");
}
namedObjects.put(id, element.value);
}
// Apply instance attributes
Dictionary<String, Object> dictionary;
if (element.value instanceof Dictionary) {
dictionary = (Dictionary<String, Object>)element.value;
} else {
dictionary = new BeanDictionary(element.value);
}
for (Attribute attribute : instancePropertyAttributes) {
dictionary.put(attribute.localName, resolve(attribute.value));
}
// If the element's parent is a sequence or a listener list, add
// the element value to it
if (element.parent != null) {
if (element.parent.value instanceof Sequence) {
Sequence<Object> sequence = (Sequence<Object>)element.parent.value;
sequence.add(element.value);
} else {
if (element.parent.value instanceof ListenerList) {
ListenerList<Object> listenerList = (ListenerList<Object>)element.parent.value;
listenerList.add(element.value);
}
}
}
// Apply static attributes
if (element.value instanceof Dictionary) {
if (staticPropertyAttributes.getLength() > 0) {
throw new SerializationException("Static setters are only supported"
+ " for typed objects.");
}
} else {
for (Attribute attribute : staticPropertyAttributes) {
setStaticProperty(attribute, element.value);
}
}
// If the parent element is a writable property, set this as its
// value; it will be applied later in the parent's closing tag
if (element.parent != null
&& element.parent.type == Element.Type.WRITABLE_PROPERTY) {
element.parent.value = element.value;
}
break;
}
case READ_ONLY_PROPERTY: {
if (element.value instanceof Dictionary<?, ?>) {
// Process attributes looking for instance property setters
for (Attribute attribute : element.attributes) {
if (Character.isUpperCase(attribute.localName.charAt(0))) {
throw new SerializationException("Static setters are not supported"
+ " for read-only properties.");
}
Dictionary<String, Object> dictionary =
(Dictionary<String, Object>)element.value;
dictionary.put(attribute.localName, resolve(attribute.value));
}
}
break;
}
case WRITABLE_PROPERTY: {
BeanDictionary beanDictionary = new BeanDictionary(element.parent.value);
beanDictionary.put(localName, element.value);
break;
}
case SCRIPT: {
// Load the script engine manager
if (scriptEngineManager == null) {
scriptEngineManager = new javax.script.ScriptEngineManager();
scriptEngineManager.setBindings(new NamedObjectBindings());
}
// Process attributes looking for src and language
String src = null;
String language = null;
for (Attribute attribute : element.attributes) {
if (attribute.prefix != null
&& attribute.prefix.length() > 0) {
throw new SerializationException(attribute.prefix + ":" +
attribute.localName + " is not a valid" + " attribute for the "
+ WTKX_PREFIX + ":" + SCRIPT_TAG + " tag.");
}
if (attribute.localName.equals(SCRIPT_SRC_ATTRIBUTE)) {
src = attribute.value;
} else if (attribute.localName.equals(SCRIPT_LANGUAGE_ATTRIBUTE)) {
language = attribute.value;
} else {
throw new SerializationException(attribute.localName + " is not a valid"
+ " attribute for the " + WTKX_PREFIX + ":" + SCRIPT_TAG + " tag.");
}
}
if (element.value != null
&& language == null) {
language = "javascript";
}
Bindings bindings;
if (element.parent.value instanceof ListenerList<?>) {
// Don't pollute the engine namespace with the listener functions
bindings = new SimpleBindings();
} else {
bindings = scriptEngineManager.getBindings();
}
// Execute script
final ScriptEngine scriptEngine;
if (src != null) {
// The script is located in an external file
if (language != null) {
throw new SerializationException("Cannot combine " + SCRIPT_SRC_ATTRIBUTE
+ " and " + SCRIPT_LANGUAGE_ATTRIBUTE + " in a "
+ WTKX_PREFIX + ":" + SCRIPT_TAG + " tag.");
}
int i = src.lastIndexOf(".");
if (i == -1) {
throw new SerializationException("Cannot determine type of script \""
+ src + "\".");
}
String extension = src.substring(i + 1);
scriptEngine = scriptEngineManager.getEngineByExtension(extension);
if (scriptEngine == null) {
throw new SerializationException("Unable to find scripting engine for"
+ " extension " + extension + ".");
}
scriptEngine.setBindings(bindings, ScriptContext.ENGINE_SCOPE);
try {
URL scriptLocation;
if (src.charAt(0) == '/') {
ClassLoader classLoader = ThreadUtilities.getClassLoader();
scriptLocation = classLoader.getResource(src);
} else {
scriptLocation = new URL(location, src);
}
BufferedReader scriptReader = null;
try {
scriptReader = new BufferedReader(new InputStreamReader(scriptLocation.openStream()));
scriptEngine.eval(scriptReader);
} catch(ScriptException exception) {
exception.printStackTrace(System.err);
} finally {
if (scriptReader != null) {
scriptReader.close();
}
}
} catch (IOException exception) {
throw new SerializationException(exception);
}
} else if (language != null) {
// The script is inline
scriptEngine = scriptEngineManager.getEngineByName(language);
if (scriptEngine == null) {
throw new SerializationException("Unable to find scripting engine for"
+ " language " + language + ".");
}
scriptEngine.setBindings(bindings, ScriptContext.ENGINE_SCOPE);
if (element.value != null) {
try {
scriptEngine.eval((String)element.value);
} catch (ScriptException exception) {
exception.printStackTrace(System.err);
}
}
} else {
throw new SerializationException("Either " + SCRIPT_SRC_ATTRIBUTE + " or "
+ SCRIPT_LANGUAGE_ATTRIBUTE + " is required for the "
+ WTKX_PREFIX + ":" + SCRIPT_TAG + " tag.");
}
if (element.parent.value instanceof ListenerList<?>) {
// Create an invocation handler for this listener
Class<?> listenerListClass = element.parent.value.getClass();
Method addMethod;
try {
addMethod = listenerListClass.getMethod("add",
new Class<?>[] {Object.class});
} catch (NoSuchMethodException exception) {
throw new RuntimeException(exception);
}
InvocationHandler handler = new InvocationHandler() {
@Override
public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable {
Object result = null;
String methodName = method.getName();
Bindings bindings = scriptEngine.getBindings(ScriptContext.ENGINE_SCOPE);
if (bindings.containsKey(methodName)) {
Invocable invocable;
try {
invocable = (Invocable)scriptEngine;
} catch (ClassCastException exception) {
throw new SerializationException(exception);
}
result = invocable.invokeFunction(methodName, args);
}
// If the function didn't return a value, return the default
Class<?> returnType = method.getReturnType();
if (returnType == Vote.class
&& result == null) {
result = Vote.APPROVE;
} else if (returnType == Boolean.TYPE
&& result == null) {
result = false;
}
return result;
}
};
// Create the listener and add it to the list
java.lang.reflect.Type[] genericInterfaces = listenerListClass.getGenericInterfaces();
Class<?> listenerClass = (Class<?>)genericInterfaces[0];
Object listener =
Proxy.newProxyInstance(ThreadUtilities.getClassLoader(),
new Class[]{listenerClass}, handler);
try {
addMethod.invoke(element.parent.value, new Object[] {listener});
} catch (IllegalAccessException exception) {
throw new SerializationException(exception);
} catch (InvocationTargetException exception) {
throw new SerializationException(exception);
}
}
break;
}
case DEFINE: {
// No-op
}
}
// Move up the stack
if (element.parent != null) {
element = element.parent;
}
break;
}
}
}
reader.close();
} catch (XMLStreamException exception) {
throw new SerializationException(exception);
}
} catch (IOException exception) {
logException(exception);
throw exception;
} catch (SerializationException exception) {
logException(exception);
throw exception;
} catch (RuntimeException exception) {
logException(exception);
throw exception;
}
// Clear the location so the previous value won't be re-used in a
// subsequent call to this method
location = null;
return root;
}
private void logException(Exception exception) {
String message = "An error occurred while processing element <" + getTagName() + ">"
+ " starting at line number " + getLineNumber();
if (location != null) {
message += " in file " + location.getPath();
}
message += ":";
System.err.println(message);
exception.printStackTrace();
}
@Override
public void writeObject(Object object, OutputStream outputStream) throws IOException,
SerializationException {
throw new UnsupportedOperationException();
}
@Override
public String getMIMEType(Object object) {
return MIME_TYPE;
}
/**
* Retrieves a named object.
*
* @param name
* The name of the object, relative to this loader. The object's name is
* the concatenation of its parent IDs and its ID, separated by periods
* (e.g. "foo.bar.baz").
*
* @return The named object, or <tt>null</tt> if an object with the given
* name does not exist. Use {@link #containsKey(String)} to distinguish
* between the two cases.
*/
@Override
public Object get(String name) {
if (name == null) {
throw new IllegalArgumentException("name is null.");
}
WTKXSerializer serializer = this;
String[] path = name.split("\\.");
Object object = null;
if (root == null) {
object = initialBindings.get(name);
} else {
int i = 0;
int n = path.length - 1;
while (i < n && serializer != null) {
String namespace = path[i++];
serializer = serializer.includeSerializers.get(namespace);
}
String id = path[i];
if (object == null && serializer != null
&& serializer.namedObjects.containsKey(id)) {
object = serializer.namedObjects.get(id);
}
// RB!! when a fully qualified name search fails
// RB!! try to find the first instance of this name
// RB!! anywhere in the tree structure
if( object == null ) {
object = find( this, name );
}
}
return object;
}
// RB!! recursively search the serializers for a name
private Object find(WTKXSerializer serializer, String name) {
Object object = null;
if( serializer.namedObjects.containsKey(name)) {
return serializer.namedObjects.get(name);
}
Iterator itr = serializer.includeSerializers.iterator();
while( itr.hasNext() && object == null ) {
serializer = serializer.includeSerializers.get(itr.next().toString());
object = find(serializer,name);
}
return object;
}
@Override
public Object put(String id, Object value) {
if (id == null) {
throw new IllegalArgumentException("id is null.");
}
root = null;
namedObjects.clear();
includeSerializers.clear();
return initialBindings.put(id, value);
}
@Override
public Object remove(String id) {
if (id == null) {
throw new IllegalArgumentException("id is null.");
}
if (root != null) {
throw new IllegalStateException();
}
return initialBindings.remove(id);
}
@Override
public boolean containsKey(String name) {
if (name == null) {
throw new IllegalArgumentException("name is null.");
}
WTKXSerializer serializer = this;
String[] path = name.split("\\.");
boolean result = false;
if (root == null) {
result = initialBindings.containsKey(name);
} else {
int i = 0;
int n = path.length - 1;
while (i < n && serializer != null) {
String namespace = path[i++];
serializer = serializer.includeSerializers.get(namespace);
}
String id = path[i];
result = (serializer != null
&& serializer.namedObjects.containsKey(id));
}
return result;
}
@Override
public boolean isEmpty() {
boolean empty = false;
if (root == null) {
empty = initialBindings.isEmpty();
} else {
empty = namedObjects.isEmpty()
&& includeSerializers.isEmpty();
}
return empty;
}
/**
* Retrieves the root of the object hierarchy most recently processed by
* this serializer.
*
* @return
* The root object, or <tt>null</tt> if this serializer has not yet read an
* object from an input stream.
*/
public Object getRoot() {
return root;
}
/**
* Retrieves an include serializer by its ID.
*
* @param id
* The ID of the serializer, relative to this loader. The serializer's ID
* is the concatentation of its parent IDs and its ID, separated by periods
* (e.g. "foo.bar.baz").
*
* @return The named serializer, or <tt>null</tt> if a serializer with the
* given name does not exist.
*/
public WTKXSerializer getSerializer(String id) {
if (id == null) {
throw new IllegalArgumentException("id is null.");
}
WTKXSerializer serializer = this;
String[] namespacePath = id.split("\\.");
int i = 0;
int n = namespacePath.length;
while (i < n && serializer != null) {
String namespace = namespacePath[i++];
serializer = serializer.includeSerializers.get(namespace);
}
return serializer;
}
/**
* Returns the name of the element currently being processed.
*
* @return
* The name of the element currently being processed, or <tt>null</tt> if
* no element is currently being processed.
*/
public String getTagName() {
return (element == null ? null : element.tagName);
}
/**
* Returns the line number of the element currently being processed.
*
* @return
* The line number of the element currently being processed, or <tt>-1</tt>
* if no element is currently being processed.
*/
public int getLineNumber() {
return (element == null ? -1 : element.lineNumber);
}
/**
* Returns the location of the WTKX currently being processed.
*
* @return
* The location of the WTKX, or <tt>null</tt> if no WTKX is currently being
* processed or the location is not known.
*/
public URL getLocation() {
return location;
}
/**
* Applies WTKX binding annotations to an object.
* <p>
* NOTE This method uses reflection to set internal member variables. As
* a result, it may only be called from trusted code.
*
* @param t
* @param type
*
* @throws BindException
* If an error occurs during binding
*/
public <T> void bind(T t, Class<? super T> type) throws BindException {
Field[] fields = type.getDeclaredFields();
// Process bind annotations
for (int j = 0, n = fields.length; j < n; j++) {
Field field = fields[j];
String fieldName = field.getName();
int fieldModifiers = field.getModifiers();
WTKX wtkxAnnotation = field.getAnnotation(WTKX.class);
if (wtkxAnnotation != null) {
// Ensure that we can write to the field
if ((fieldModifiers & Modifier.FINAL) > 0) {
throw new BindException(fieldName + " is final.");
}
if ((fieldModifiers & Modifier.PUBLIC) == 0) {
try {
field.setAccessible(true);
} catch (SecurityException exception) {
throw new BindException(fieldName + " is not accessible.");
}
}
String id = wtkxAnnotation.id();
if (id.equals("\0")) {
id = field.getName();
}
// Set the value into the field
// RB!! changed to call get without call to contains
// RB!! as the get method will do the work once
Object value = get(id);
if (value!=null) {
try {
field.set(t, value);
} catch (IllegalAccessException exception) {
throw new BindException(exception);
}
}
}
}
}
/**
* Resolves an attribute value as either a URL, resource value, or
* object reference, depending on the value's prefix. If the value can't
* or doesn't need to be resolved, the original attribute value is
* returned.
*
* @param attributeValue
* The attribute value to resolve.
*
* @return
* The resolved value.
*/
private Object resolve(String attributeValue)
throws MalformedURLException {
Object resolvedValue = null;
if (attributeValue.length() > 0) {
if (attributeValue.charAt(0) == URL_PREFIX) {
if (attributeValue.length() > 1) {
if (attributeValue.charAt(1) == URL_PREFIX) {
resolvedValue = attributeValue.substring(1);
} else {
if (location == null) {
throw new IllegalStateException("Base location is undefined.");
}
resolvedValue = new URL(location, attributeValue.substring(1));
}
}
} else if (attributeValue.charAt(0) == RESOURCE_KEY_PREFIX) {
if (attributeValue.length() > 1) {
if (attributeValue.charAt(1) == RESOURCE_KEY_PREFIX) {
resolvedValue = attributeValue.substring(1);
} else {
if (resources == null) {
throw new IllegalStateException("Resources is null.");
}
resolvedValue = resources.get(attributeValue.substring(1));
if (resolvedValue == null) {
resolvedValue = attributeValue;
}
}
}
} else if (attributeValue.charAt(0) == OBJECT_REFERENCE_PREFIX) {
if (attributeValue.length() > 1) {
if (attributeValue.charAt(1) == OBJECT_REFERENCE_PREFIX) {
resolvedValue = attributeValue.substring(1);
} else {
resolvedValue = get(attributeValue.substring(1));
if (resolvedValue == null) {
resolvedValue = attributeValue;
}
}
}
} else {
resolvedValue = attributeValue;
}
} else {
resolvedValue = attributeValue;
}
return resolvedValue;
}
/**
* Invokes a static property setter.
*
* @param attribute
* The attribute whose corresponding static setter is to be invoked.
*
* @param object
* The object on which to invoke the static setter.
*/
private void setStaticProperty(Attribute attribute, Object object)
throws SerializationException, MalformedURLException {
Object value = resolve(attribute.value);
Class<?> objectType = object.getClass();
String propertyName =
attribute.localName.substring(attribute.localName.lastIndexOf(".") + 1);
propertyName = Character.toUpperCase(propertyName.charAt(0)) +
propertyName.substring(1);
String propertyClassName = attribute.namespaceURI + "."
+ attribute.localName.substring(0, attribute.localName.length()
- (propertyName.length() + 1));
Class<?> propertyClass = null;
try {
propertyClass = Class.forName(propertyClassName);
} catch (ClassNotFoundException exception) {
throw new SerializationException(exception);
}
Method setterMethod = null;
if (value != null) {
setterMethod = getStaticSetterMethod(propertyClass, propertyName,
objectType, value.getClass());
}
if (setterMethod == null) {
Method getterMethod = getStaticGetterMethod(propertyClass, propertyName, objectType);
if (getterMethod != null) {
Class<?> propertyType = getterMethod.getReturnType();
setterMethod = getStaticSetterMethod(propertyClass, propertyName,
objectType, propertyType);
if (value instanceof String) {
value = BeanDictionary.coerce((String)value, propertyType);
}
}
}
if (setterMethod == null) {
throw new SerializationException(attribute.localName + " is not valid static property.");
}
// Invoke the setter
try {
setterMethod.invoke(null, new Object[] {object, value});
} catch (Exception exception) {
throw new SerializationException(exception);
}
}
private Method getStaticGetterMethod(Class<?> propertyClass, String propertyName,
Class<?> objectType) {
Method method = null;
if (objectType != null) {
try {
method = propertyClass.getMethod(BeanDictionary.GET_PREFIX
+ propertyName, new Class<?>[] {objectType});
} catch (NoSuchMethodException exception) {
// No-op
}
if (method == null) {
try {
method = propertyClass.getMethod(BeanDictionary.IS_PREFIX
+ propertyName, new Class<?>[] {objectType});
} catch (NoSuchMethodException exception) {
// No-op
}
}
if (method == null) {
method = getStaticGetterMethod(propertyClass, propertyName,
objectType.getSuperclass());
}
}
return method;
}
private Method getStaticSetterMethod(Class<?> propertyClass, String propertyName,
Class<?> objectType, Class<?> propertyValueType) {
Method method = null;
if (objectType != null) {
final String methodName = BeanDictionary.SET_PREFIX + propertyName;
try {
method = propertyClass.getMethod(methodName,
new Class<?>[] {objectType, propertyValueType});
} catch (NoSuchMethodException exception) {
// No-op
}
if (method == null) {
// If value type is a primitive wrapper, look for a method
// signature with the corresponding primitive type
try {
Field primitiveTypeField = propertyValueType.getField("TYPE");
Class<?> primitivePropertyValueType = (Class<?>)primitiveTypeField.get(null);
try {
method = propertyClass.getMethod(methodName,
new Class<?>[] {objectType, primitivePropertyValueType});
} catch (NoSuchMethodException exception) {
// No-op
}
} catch (NoSuchFieldException exception) {
// No-op; not a wrapper type
} catch (IllegalAccessException exception) {
// No-op; not a wrapper type
}
}
if (method == null) {
method = getStaticSetterMethod(propertyClass, propertyName,
objectType.getSuperclass(), propertyValueType);
}
}
return method;
}
public ListenerList<WTKXSerializerListener> getWTKXSerializerListeners() {
return wtkxSerializerListeners;
}
}
Re: Pivot auto-binding query
Posted by Roy Bailey <ro...@odinium.com>.
Sure, the base code was from v1.3 tag, so it may be you compared with
the latest dev branch.
I placed three pieces of code, all with a comment header RB!! You can
search on this to see what I did and get the idea.
In essence I want to gather opinion on plans and/or strategies for
auto-binding variables and trigger methods to reduce plumbing. This
code snippet was just a example of the direction I wanted to explore;
allowing complex include structures in the gui mark-up files but use
flat global names in the controller variables to bind automatically.
cheers...Roy
Todd Volkert wrote:
> As far as I understand it, tossing around ideas in code is fine to do over
> email. Project Mentors, please correct me if I'm wrong.
>
> So I tried diffing what you sent against the WTKXSerializer in SVN, but the
> diff was so substantive that it was hard to understand the change -- can you
> describe what the change does?
>
> Cheers,
> -T
>
> On Fri, Oct 2, 2009 at 5:41 PM, Roy Bailey <ro...@odinium.com> wrote:
>
>
>> I was more playing and wanted to get some opinions and make sure I wasn't
>> wasting time on something people already have in the pipeline (and strong
>> opinions that differ from my own :)
>>
>> I would probably play some more before I wanted to sumbit something as a
>> patch to be reviewed and possibly included in the official build. Or does
>> conversational example code need to go through the JIRA process also?
>>
>> I've not actively participated in an open source project before, so this is
>> all new.
>>
>> regards...
>> Roy
>>
>>
>>
>> Todd Volkert wrote:
>>
>>
>>> Hi Roy,
>>>
>>> If this is a patch, can you please submit it by attaching it to a new JIRA
>>> ticket (http://issues.apache.org/jira/browse/PIVOT)? Routing
>>> contributions
>>> through JIRA help with possible legal ramifications.
>>>
>>> Thanks,
>>> -T
>>>
>>>
>>>
>>>
>
>
Re: Pivot auto-binding query
Posted by Todd Volkert <tv...@gmail.com>.
As far as I understand it, tossing around ideas in code is fine to do over
email. Project Mentors, please correct me if I'm wrong.
So I tried diffing what you sent against the WTKXSerializer in SVN, but the
diff was so substantive that it was hard to understand the change -- can you
describe what the change does?
Cheers,
-T
On Fri, Oct 2, 2009 at 5:41 PM, Roy Bailey <ro...@odinium.com> wrote:
> I was more playing and wanted to get some opinions and make sure I wasn't
> wasting time on something people already have in the pipeline (and strong
> opinions that differ from my own :)
>
> I would probably play some more before I wanted to sumbit something as a
> patch to be reviewed and possibly included in the official build. Or does
> conversational example code need to go through the JIRA process also?
>
> I've not actively participated in an open source project before, so this is
> all new.
>
> regards...
> Roy
>
>
>
> Todd Volkert wrote:
>
>> Hi Roy,
>>
>> If this is a patch, can you please submit it by attaching it to a new JIRA
>> ticket (http://issues.apache.org/jira/browse/PIVOT)? Routing
>> contributions
>> through JIRA help with possible legal ramifications.
>>
>> Thanks,
>> -T
>>
>>
>>
>
Re: Pivot auto-binding query
Posted by Roy Bailey <ro...@odinium.com>.
I was more playing and wanted to get some opinions and make sure I
wasn't wasting time on something people already have in the pipeline
(and strong opinions that differ from my own :)
I would probably play some more before I wanted to sumbit something as a
patch to be reviewed and possibly included in the official build. Or
does conversational example code need to go through the JIRA process also?
I've not actively participated in an open source project before, so this
is all new.
regards...
Roy
Todd Volkert wrote:
> Hi Roy,
>
> If this is a patch, can you please submit it by attaching it to a new JIRA
> ticket (http://issues.apache.org/jira/browse/PIVOT)? Routing contributions
> through JIRA help with possible legal ramifications.
>
> Thanks,
> -T
>
>
Re: Pivot auto-binding query
Posted by Greg Brown <gk...@mac.com>.
> Shame about the applet restriction. Any way to save plumbing time
> and code noise is important for a modern api and using convention
> rules is a good way of offering this. It sounds like the WTKX
> annotation is all you have planned for now, so I'll continue
> building out my application and think about this some more. Being
> 'efficient' with my time (some might call it lazy :) I will probably
> build some utility class to do more complex auto-binding and I'll
> shame my thoughts/code if I get something like a potential patch
> together.
Sounds good. Keep in mind that you can use @WTKX in a signed applet.
Many non-trivial applications delivered as applets will need to be
signed anyways (for example, if the application needs to access the
local file system). Also, you can access named values directly from
script defined within or included by the page, either in a
<wtkx:script> block or in an attribute-based event handler. So, you
may want to spend a some time playing with these options before
pursuing a more complex alternative.
However, if you do end up prototyping some other approaches, we would
love to hear about your experiences.
Thanks,
Greg
Re: Pivot auto-binding query
Posted by Roy Bailey <ro...@odinium.com>.
Spot on Greg,
Your proposal is much better, if the include id is only used to
namespace the contents and you loose nothing else by leaving this out.
It seems quite logical then to breakdown the view of some controller
class into parts without qualifying them if you wish to keep the
controller variables/bindings flat.
Shame about the applet restriction. Any way to save plumbing time and
code noise is important for a modern api and using convention rules is a
good way of offering this. It sounds like the WTKX annotation is all
you have planned for now, so I'll continue building out my application
and think about this some more. Being 'efficient' with my time (some
might call it lazy :) I will probably build some utility class to do
more complex auto-binding and I'll shame my thoughts/code if I get
something like a potential patch together.
thanks...Roy
Greg Brown wrote:
>> If this is a patch, can you please submit it by attaching it to a new
>> JIRA
>> ticket (http://issues.apache.org/jira/browse/PIVOT)? Routing
>> contributions
>> through JIRA help with possible legal ramifications.
>
> That was my bad - I forgot that we are managing patch submissions via
> JIRA now and had asked Roy to post it to the list directly.
>
> Roy-
>
> Regarding the patch: if I understand you correctly, I believe it is
> intended to make WTKX IDs defined in an include available in the
> parent namespace without needing to qualify the name with the
> include's ID. Is that correct? For example, given the following WTKX:
>
> foo.wtkx:
>
> <Window>
> <content>
> <wtkx:include wtkx:id="bar" src="bar.wtkx"/>
> </content>
> </Window>
>
> bar.wtkx
>
> <BoxPane>
> <Label wtkx:id="myLabel"/>
> </BoxPane>
>
> The "label" value would now be accessible via get("myLabel") on the
> root serializer, not just get("bar.myLabel").
>
> I'm not sure I like that particular solution, since I think it could
> generate confusion. For example, what if "myLabel" is also defined in
> the parent include? However, I have another suggestion that might suit
> your needs (I actually think Noel may have made a similar suggestion a
> while back). Currently, if an include defines named values and isn't
> given an ID itself, WTKXSerializer displays a warning (because there's
> no way to access those values). However, we could simply add those
> named objects to the parent namespace in that case. If the
> <wtkx:include> tag does have a "wtkx:id" attribute, they would remain
> accessible via the fully-qualified name only.
>
> Would this address what you are trying to accomplish?
>
> In response to the other question you had asked about why we don't use
> the @WTKX annotation in the tutorials: WTKX binding uses reflection to
> set member variables, which are generally private. This is considered
> a privileged operation by the JVM, and untrusted code (such as that
> which often runs in a web browser) isn't allowed to execute it. Using
> @WTKX in the tutorials would require us to sign all of the tutorial
> apps, which wouldn't otherwise be necessary.
>
> Greg
>
>
Re: Pivot auto-binding query
Posted by Greg Brown <gk...@mac.com>.
> If this is a patch, can you please submit it by attaching it to a
> new JIRA
> ticket (http://issues.apache.org/jira/browse/PIVOT)? Routing
> contributions
> through JIRA help with possible legal ramifications.
That was my bad - I forgot that we are managing patch submissions via
JIRA now and had asked Roy to post it to the list directly.
Roy-
Regarding the patch: if I understand you correctly, I believe it is
intended to make WTKX IDs defined in an include available in the
parent namespace without needing to qualify the name with the
include's ID. Is that correct? For example, given the following WTKX:
foo.wtkx:
<Window>
<content>
<wtkx:include wtkx:id="bar" src="bar.wtkx"/>
</content>
</Window>
bar.wtkx
<BoxPane>
<Label wtkx:id="myLabel"/>
</BoxPane>
The "label" value would now be accessible via get("myLabel") on the
root serializer, not just get("bar.myLabel").
I'm not sure I like that particular solution, since I think it could
generate confusion. For example, what if "myLabel" is also defined in
the parent include? However, I have another suggestion that might suit
your needs (I actually think Noel may have made a similar suggestion a
while back). Currently, if an include defines named values and isn't
given an ID itself, WTKXSerializer displays a warning (because there's
no way to access those values). However, we could simply add those
named objects to the parent namespace in that case. If the
<wtkx:include> tag does have a "wtkx:id" attribute, they would remain
accessible via the fully-qualified name only.
Would this address what you are trying to accomplish?
In response to the other question you had asked about why we don't use
the @WTKX annotation in the tutorials: WTKX binding uses reflection to
set member variables, which are generally private. This is considered
a privileged operation by the JVM, and untrusted code (such as that
which often runs in a web browser) isn't allowed to execute it. Using
@WTKX in the tutorials would require us to sign all of the tutorial
apps, which wouldn't otherwise be necessary.
Greg
Re: Pivot auto-binding query
Posted by Todd Volkert <tv...@gmail.com>.
Hi Roy,
If this is a patch, can you please submit it by attaching it to a new JIRA
ticket (http://issues.apache.org/jira/browse/PIVOT)? Routing contributions
through JIRA help with possible legal ramifications.
Thanks,
-T