/**
* Copyright (c) 2010 Google Inc.
*
* 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 com.google.wave.api.v2;
import com.google.gson.JsonDeserializationContext;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParseException;
import com.google.gson.JsonSerializationContext;
import com.google.wave.api.Attachment;
import com.google.wave.api.Element;
import com.google.wave.api.ElementType;
import com.google.wave.api.Image;
import com.google.wave.api.impl.ElementGsonAdaptor;
import com.google.wave.api.impl.GsonFactory;
import java.lang.reflect.Type;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
/**
* Gson adaptor to serialize and deserialize {@link Element}. In v0.2, we still
* use {@link Image} to represents attachment, so we need to convert all
* attachment objects into Image.
*
* @author jli@google.com (Jimin Li)
* @author mprasetya@google.com (Marcel Prasetya)
*/
public class ElementGsonAdaptorV2 extends ElementGsonAdaptor {
private static final Set<String> ATTACHMENT_ONLY_PROPERTIES = new HashSet<String>(
Arrays.asList(Attachment.MIME_TYPE, Attachment.DATA, Attachment.ATTACHMENT_URL));
@Override
public JsonElement serialize(Element src, Type typeOfSrc, JsonSerializationContext context) {
if (src.getType() == ElementType.ATTACHMENT) {
src = new Element(ElementType.IMAGE, createImageProperties(src.getProperties()));
}
return super.serialize(src, typeOfSrc, context);
}
@Override
public Element deserialize(JsonElement jsonElement, Type typeOfT,
JsonDeserializationContext context) throws JsonParseException {
JsonObject json = jsonElement.getAsJsonObject();
String type = json.get(TYPE_TAG).getAsString();
if (ElementType.IMAGE.name().equals(type)) {
JsonObject properties = json.getAsJsonObject(PROPERTIES_TAG);
if (!properties.has(Image.URL)) {
json.addProperty(TYPE_TAG, ElementType.ATTACHMENT.name());
}
}
return super.deserialize(json, typeOfT, context);
}
static Map<String, String> createImageProperties(Map<String, String> props) {
Map<String, String> imageProps = new HashMap<String, String>();
Iterator<Entry<String, String>> iter = props.entrySet().iterator();
while (iter.hasNext()) {
Entry<String, String> next = iter.next();
// Removes attachment only properties, and provides backward compatible
// image support to python robot with protocol version 0.2
if (!ATTACHMENT_ONLY_PROPERTIES.contains(next.getKey())) {
imageProps.put(next.getKey(), next.getValue());
}
}
return imageProps;
}
/**
* Registers this {@link ElementGsonAdaptorV2} with the given
* {@link GsonFactory}.
* @param factory {@link GsonFactory} to register the type adapters with
* @return the given {@link GsonFactory} with the registered adapters
*/
public static GsonFactory registerTypeAdapters(GsonFactory factory) {
ElementGsonAdaptorV2 elementGsonAdaptorV2 = new ElementGsonAdaptorV2();
factory.registerTypeAdapter(Element.class, elementGsonAdaptorV2);
factory.registerTypeAdapter(Attachment.class, elementGsonAdaptorV2);
return factory;
}
}