/* Copyright (c) 2008 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.gdata.data.extensions;
import com.google.gdata.util.common.xml.XmlWriter;
import com.google.gdata.client.CoreErrorDomain;
import com.google.gdata.data.ExtensionDescription;
import com.google.gdata.data.ExtensionPoint;
import com.google.gdata.data.ExtensionProfile;
import com.google.gdata.util.Namespaces;
import com.google.gdata.util.ParseException;
import com.google.gdata.util.XmlParser.ElementHandler;
import org.xml.sax.Attributes;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
/**
* GData schema extension describing an object's rating.
*
*
*/
public class Rating extends ExtensionPoint {
/**
* Rating type. Describes the meaning of this rating.
*/
public static final class Rel {
/** Overall rating. Higher values mean better ratings. */
public static final String OVERALL = null;
/** Quality rating. Higher values mean better quality. */
public static final String QUALITY = Namespaces.gPrefix + "quality";
/** Price rating. Higher values mean higher prices. */
public static final String PRICE = Namespaces.gPrefix + "price";
}
/**
* Constructs an empty {@code Rating}.
*/
public Rating() {
this(null);
}
/**
* Constructs a {@code Rating} class with a specified rating.
*
* @param rating the value of the rating
*/
public Rating(Integer rating) {
this.rating = rating;
}
/** Rating type. */
protected String rel;
public String getRel() {
return rel;
}
public void setRel(String v) {
rel = v;
}
/** Rating value (required). */
protected Integer rating;
public Integer getValue() {
return rating;
}
public void setValue(Integer r) {
rating = r;
}
/** Minimum rating value on rating scale (optional). */
protected Integer min;
public Integer getMin() {
return min;
}
public void setMin(Integer r) {
min = r;
}
/** Maximum rating value on rating scale (optional). */
protected Integer max;
public Integer getMax() {
return max;
}
public void setMax(Integer r) {
max = r;
}
/** Number of ratings that was taken into account (for average ratings). */
protected Integer numRaters;
public Integer getNumRaters() {
return numRaters;
}
public void setNumRaters(Integer r) {
numRaters = r;
}
/** Average ratings, output with a fixed a 2 digit precision. */
protected Float average;
public Float getAverage() {
return average;
}
public void setAverage(Float r) {
average = r;
}
/**
* Returns the suggested extension description with configurable
* repeatability.
*/
public static ExtensionDescription getDefaultDescription(boolean repeatable) {
ExtensionDescription desc = new ExtensionDescription();
desc.setExtensionClass(Rating.class);
desc.setNamespace(Namespaces.gNs);
desc.setLocalName("rating");
desc.setRepeatable(repeatable);
return desc;
}
/** Returns the suggested extension description and is repeatable. */
public static ExtensionDescription getDefaultDescription() {
return getDefaultDescription(true);
}
@Override
public void generate(XmlWriter w, ExtensionProfile extProfile)
throws IOException {
List<XmlWriter.Attribute> attrs = new ArrayList<XmlWriter.Attribute>();
if (rel != null) {
attrs.add(new XmlWriter.Attribute("rel", rel));
}
if (rating != null) {
attrs.add(new XmlWriter.Attribute("value", rating.toString()));
}
if (min != null) {
attrs.add(new XmlWriter.Attribute("min", min.toString()));
}
if (max != null) {
attrs.add(new XmlWriter.Attribute("max", max.toString()));
}
if (numRaters != null) {
attrs.add(new XmlWriter.Attribute("numRaters", numRaters.toString()));
}
if (average != null) {
attrs.add(
new XmlWriter.Attribute("average", String.format("%2.2f", average)));
}
generateStartElement(w, Namespaces.gNs, "rating", attrs, null);
// Invoke ExtensionPoint.
generateExtensions(w, extProfile);
w.endElement(Namespaces.gNs, "rating");
}
@Override
public ElementHandler getHandler(ExtensionProfile extProfile,
String namespace,
String localName,
Attributes attrs) {
return new Handler(extProfile);
}
/** <gd:rating> parser */
private class Handler extends ExtensionPoint.ExtensionHandler {
public Handler(ExtensionProfile extProfile) {
super(extProfile, Rating.class);
}
@Override
public void processAttribute(String namespace,
String localName,
String value)
throws NumberFormatException {
if (namespace.equals("")) {
if (localName.equals("value")) {
rating = Integer.parseInt(value);
} else if (localName.equals("max")) {
max = Integer.parseInt(value);
} else if (localName.equals("min")) {
min = Integer.parseInt(value);
} else if (localName.equals("rel")) {
rel = value;
} else if (localName.equals("numRaters")) {
numRaters = Integer.parseInt(value);
} else if (localName.equals("average")) {
average = Float.valueOf(value);
}
}
}
@Override
public void processEndElement() throws ParseException {
if (rating == null && average == null) {
throw new ParseException(
CoreErrorDomain.ERR.valueOrAverageRequired);
}
if (rating != null) {
if (min != null && rating < min || max != null && rating > max) {
throw new ParseException(
CoreErrorDomain.ERR.invalidValueRatingAttribute);
}
}
if (average != null) {
if (min != null && average < min || max != null && average > max) {
throw new ParseException(
CoreErrorDomain.ERR.invalidAverageRatingAttribute);
}
}
}
}
}