/*
* Copyright 2013 Nicolas Morel
*
* 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.github.nmorel.gwtjackson.client.ser;
import java.util.Iterator;
import com.github.nmorel.gwtjackson.client.JsonSerializationContext;
import com.github.nmorel.gwtjackson.client.JsonSerializer;
import com.github.nmorel.gwtjackson.client.JsonSerializerParameters;
import com.github.nmorel.gwtjackson.client.stream.JsonWriter;
/**
* Default {@link JsonSerializer} implementation for {@link Iterable}.
*
* @param <T> Type of the elements inside the {@link Iterable}
* @author Nicolas Morel
* @version $Id: $
*/
public class IterableJsonSerializer<I extends Iterable<T>, T> extends JsonSerializer<I> {
/**
* <p>newInstance</p>
*
* @param serializer {@link JsonSerializer} used to serialize the objects inside the {@link Iterable}.
* @param <I> the type
* @return a new instance of {@link IterableJsonSerializer}
*/
public static <I extends Iterable<?>> IterableJsonSerializer<I, ?> newInstance( JsonSerializer<?> serializer ) {
return new IterableJsonSerializer( serializer );
}
protected final JsonSerializer<T> serializer;
/**
* <p>Constructor for IterableJsonSerializer.</p>
*
* @param serializer {@link JsonSerializer} used to serialize the objects inside the {@link Iterable}.
*/
protected IterableJsonSerializer( JsonSerializer<T> serializer ) {
if ( null == serializer ) {
throw new IllegalArgumentException( "serializer cannot be null" );
}
this.serializer = serializer;
}
/** {@inheritDoc} */
@Override
protected boolean isEmpty( I value ) {
return null == value || !value.iterator().hasNext();
}
/** {@inheritDoc} */
@Override
public void doSerialize( JsonWriter writer, I values, JsonSerializationContext ctx, JsonSerializerParameters params ) {
Iterator<T> iterator = values.iterator();
if ( !iterator.hasNext() ) {
if ( ctx.isWriteEmptyJsonArrays() ) {
writer.beginArray();
writer.endArray();
} else {
writer.cancelName();
}
return;
}
if ( ctx.isWriteSingleElemArraysUnwrapped() ) {
T first = iterator.next();
if ( iterator.hasNext() ) {
// there is more than one element, we write the array normally
writer.beginArray();
serializer.serialize( writer, first, ctx, params );
while ( iterator.hasNext() ) {
serializer.serialize( writer, iterator.next(), ctx, params );
}
writer.endArray();
} else {
// there is only one element, we write it directly
serializer.serialize( writer, first, ctx, params );
}
} else {
writer.beginArray();
while ( iterator.hasNext() ) {
serializer.serialize( writer, iterator.next(), ctx, params );
}
writer.endArray();
}
}
}