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/*
* CompositeInlineList.java July 2006
*
* Copyright (C) 2006, Niall Gallagher
*
* Licensed 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.simpleframework.xml.core;
import java.util.Collection;
import org.simpleframework.xml.strategy.Type;
import org.simpleframework.xml.stream.InputNode;
import org.simpleframework.xml.stream.OutputNode;
/**
* The CompositeInlineList object is used to convert an
* group of elements in to a collection of element entries. This is
* used when a containing element for a list is not required. It
* extracts the elements by matching elements to name of the type
* that the annotated field or method requires. This enables these
* element entries to exist as siblings to other objects within the
* object. One restriction is that the Root annotation
* for each of the types within the list must be the same.
*
*
* <entry attribute="one">
* <text>example text value</text>
* </entry>
* <entry attribute="two">
* <text>some other example</text>
* </entry>
* <entry attribute="three">
* <text>yet another example</text>
* </entry>
*
*
* For the above XML element list the element entry is
* contained within the list. Each entry element is thus deserialized
* as a root element and then inserted into the list. This enables
* lists to be composed from XML documents. For serialization the
* reverse is done, each element taken from the collection is written
* as a root element to the owning element to create the list.
* Entry objects do not need to be of the same type.
*
* @author Niall Gallagher
*
* @see org.simpleframework.xml.core.Traverser
* @see org.simpleframework.xml.ElementList
*/
class CompositeInlineList implements Repeater {
/**
* This factory is used to create a suitable collection list.
*/
private final CollectionFactory factory;
/**
* This performs the traversal used for object serialization.
*/
private final Traverser root;
/**
* This represents the name of the entry elements to write.
*/
private final String name;
/**
* This is the entry type for elements within the list.
*/
private final Type entry;
/**
* This represents the actual method or field for the list.
*/
private final Type type;
/**
* Constructor for the CompositeInlineList object.
* This is given the list type and entry type to be used. The list
* type is the Collection implementation that is used
* to collect the deserialized entry objects from the XML source.
*
* @param context this is the context object used for serialization
* @param type this is the collection type for the list used
* @param entry the entry type to be stored within the list
* @param name this is the name of the entries used for this list
*/
public CompositeInlineList(Context context, Type type, Type entry, String name) {
this.factory = new CollectionFactory(context, type);
this.root = new Traverser(context);
this.entry = entry;
this.type = type;
this.name = name;
}
/**
* This read method wll read the XML element list from
* the provided node and deserialize its children as entry types.
* This will each entry type is deserialized as a root type, that
* is, its Root annotation must be present and the
* name of the entry element must match that root element name.
*
* @param node this is the XML element that is to be deserialized
*
* @return this returns the item to attach to the object contact
*/
public Object read(InputNode node) throws Exception{
Object value = factory.getInstance();
Collection list = (Collection) value;
if(list != null) {
return read(node, list);
}
return null;
}
/**
* This read method will read the XML element list from
* the provided node and deserialize its children as entry types.
* This will each entry type is deserialized as a root type, that
* is, its Root annotation must be present and the
* name of the entry element must match that root element name.
*
* @param node this is the XML element that is to be deserialized
*
* @return this returns the item to attach to the object contact
*/
public Object read(InputNode node, Object value) throws Exception {
Collection list = (Collection) value;
if(list != null) {
return read(node, list);
}
return read(node);
}
/**
* This read method wll read the XML element list from
* the provided node and deserialize its children as entry types.
* This will each entry type is deserialized as a root type, that
* is, its Root annotation must be present and the
* name of the entry element must match that root element name.
*
* @param node this is the XML element that is to be deserialized
* @param list this is the collection that is to be populated
*
* @return this returns the item to attach to the object contact
*/
private Object read(InputNode node, Collection list) throws Exception {
InputNode from = node.getParent();
String name = node.getName();
while(node != null) {
Class type = entry.getType();
Object item = read(node, type);
if(item != null) {
list.add(item);
}
node = from.getNext(name);
}
return list;
}
/**
* This read method will read the XML element from the
* provided node. This checks to ensure that the deserialized type
* is the same as the entry type provided. If the types are not
* the same then an exception is thrown. This is done to ensure
* each node in the collection contain the same root annotation.
*
* @param node this is the XML element that is to be deserialized
* @param expect this is the type expected of the deserialized type
*
* @return this returns the item to attach to the object contact
*/
private Object read(InputNode node, Class expect) throws Exception {
Object item = root.read(node, expect);
Class result = item.getClass();
Class actual = entry.getType();
if(!actual.isAssignableFrom(result)) {
throw new PersistenceException("Entry %s does not match %s for %s", result, entry, type);
}
return item;
}
/**
* This read method will read the XML element list from
* the provided node and deserialize its children as entry types.
* This will each entry type is deserialized as a root type, that
* is, its Root annotation must be present and the
* name of the entry element must match that root element name.
*
* @param node this is the XML element that is to be deserialized
*
* @return this returns the item to attach to the object contact
*/
public boolean validate(InputNode node) throws Exception{
InputNode from = node.getParent();
Class type = entry.getType();
String name = node.getName();
while(node != null) {
boolean valid = root.validate(node, type);
if(valid == false) {
return false;
}
node = from.getNext(name);
}
return true;
}
/**
* This write method will write the specified object
* to the given XML element as as list entries. Each entry within
* the given collection must be assignable from the annotated
* type specified within the ElementList annotation.
* Each entry is serialized as a root element, that is, its
* Root annotation is used to extract the name.
*
* @param source this is the source collection to be serialized
* @param node this is the XML element container to be populated
*/
public void write(OutputNode node, Object source) throws Exception {
Collection list = (Collection) source;
OutputNode parent = node.getParent();
if(!node.isCommitted()) {
node.remove();
}
write(parent, list);
}
/**
* This write method will write the specified object
* to the given XML element as as list entries. Each entry within
* the given collection must be assignable from the annotated
* type specified within the ElementList annotation.
* Each entry is serialized as a root element, that is, its
* Root annotation is used to extract the name.
*
* @param list this is the source collection to be serialized
* @param node this is the XML element container to be populated
*/
public void write(OutputNode node, Collection list) throws Exception {
for(Object item : list) {
if(item != null) {
Class expect = entry.getType();
Class actual = item.getClass();
if(!expect.isAssignableFrom(actual)) {
throw new PersistenceException("Entry %s does not match %s for %s", actual, expect, type);
}
root.write(node, item, expect, name);
}
}
}
}