/*
* Copyright 2004 Sun Microsystems, 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.rometools.rome.io.impl;
import java.util.List;
import org.jdom2.Document;
import org.jdom2.Element;
import org.jdom2.Namespace;
import com.rometools.rome.feed.WireFeed;
import com.rometools.rome.feed.rss.Channel;
import com.rometools.rome.feed.rss.Image;
import com.rometools.rome.feed.rss.Item;
import com.rometools.rome.feed.rss.TextInput;
import com.rometools.rome.io.FeedException;
/**
* Feed Generator for RSS 0.90
* <p/>
*
* @author Elaine Chien
*/
public class RSS090Generator extends BaseWireFeedGenerator {
private static final String RDF_URI = "http://www.w3.org/1999/02/22-rdf-syntax-ns#";
private static final String RSS_URI = "http://my.netscape.com/rdf/simple/0.9/";
private static final String CONTENT_URI = "http://purl.org/rss/1.0/modules/content/";
private static final Namespace RDF_NS = Namespace.getNamespace("rdf", RDF_URI);
private static final Namespace RSS_NS = Namespace.getNamespace(RSS_URI);
private static final Namespace CONTENT_NS = Namespace.getNamespace("content", CONTENT_URI);
public RSS090Generator() {
this("rss_0.9");
}
protected RSS090Generator(final String type) {
super(type);
}
@Override
public Document generate(final WireFeed feed) throws FeedException {
final Channel channel = (Channel) feed;
final Element root = createRootElement(channel);
populateFeed(channel, root);
purgeUnusedNamespaceDeclarations(root);
return createDocument(root);
}
protected Namespace getFeedNamespace() {
return RSS_NS;
}
protected Namespace getRDFNamespace() {
return RDF_NS;
}
protected Namespace getContentNamespace() {
return CONTENT_NS;
}
protected Document createDocument(final Element root) {
return new Document(root);
}
protected Element createRootElement(final Channel channel) {
final Element root = new Element("RDF", getRDFNamespace());
root.addNamespaceDeclaration(getFeedNamespace());
root.addNamespaceDeclaration(getRDFNamespace());
root.addNamespaceDeclaration(getContentNamespace());
generateModuleNamespaceDefs(root);
return root;
}
protected void populateFeed(final Channel channel, final Element parent) throws FeedException {
addChannel(channel, parent);
addImage(channel, parent);
addTextInput(channel, parent);
addItems(channel, parent);
generateForeignMarkup(parent, channel.getForeignMarkup());
}
protected void addChannel(final Channel channel, final Element parent) throws FeedException {
final Element eChannel = new Element("channel", getFeedNamespace());
populateChannel(channel, eChannel);
checkChannelConstraints(eChannel);
parent.addContent(eChannel);
generateFeedModules(channel.getModules(), eChannel);
}
/**
* Populates the given channel with parsed data from the ROME element that holds the channel
* data.
*
* @param channel the channel into which parsed data will be added.
* @param eChannel the XML element that holds the data for the channel.
*/
protected void populateChannel(final Channel channel, final Element eChannel) {
final String title = channel.getTitle();
if (title != null) {
eChannel.addContent(generateSimpleElement("title", title));
}
final String link = channel.getLink();
if (link != null) {
eChannel.addContent(generateSimpleElement("link", link));
}
final String description = channel.getDescription();
if (description != null) {
eChannel.addContent(generateSimpleElement("description", description));
}
}
// maxLen == -1 means unlimited.
protected void checkNotNullAndLength(final Element parent, final String childName, final int minLen, final int maxLen) throws FeedException {
final Element child = parent.getChild(childName, getFeedNamespace());
if (child == null) {
throw new FeedException("Invalid " + getType() + " feed, missing " + parent.getName() + " " + childName);
}
checkLength(parent, childName, minLen, maxLen);
}
// maxLen == -1 means unlimited.
protected void checkLength(final Element parent, final String childName, final int minLen, final int maxLen) throws FeedException {
final Element child = parent.getChild(childName, getFeedNamespace());
if (child != null) {
if (minLen > 0 && child.getText().length() < minLen) {
throw new FeedException("Invalid " + getType() + " feed, " + parent.getName() + " " + childName + "short of " + minLen + " length");
}
if (maxLen > -1 && child.getText().length() > maxLen) {
throw new FeedException("Invalid " + getType() + " feed, " + parent.getName() + " " + childName + "exceeds " + maxLen + " length");
}
}
}
protected void addImage(final Channel channel, final Element parent) throws FeedException {
final Image image = channel.getImage();
if (image != null) {
final Element eImage = new Element("image", getFeedNamespace());
populateImage(image, eImage);
checkImageConstraints(eImage);
parent.addContent(eImage);
}
}
protected void populateImage(final Image image, final Element eImage) {
final String title = image.getTitle();
if (title != null) {
eImage.addContent(generateSimpleElement("title", title));
}
final String url = image.getUrl();
if (url != null) {
eImage.addContent(generateSimpleElement("url", url));
}
final String link = image.getLink();
if (link != null) {
eImage.addContent(generateSimpleElement("link", link));
}
}
// Thxs DW for this one
protected String getTextInputLabel() {
return "textInput";
}
protected void addTextInput(final Channel channel, final Element parent) throws FeedException {
final TextInput textInput = channel.getTextInput();
if (textInput != null) {
final Element eTextInput = new Element(getTextInputLabel(), getFeedNamespace());
populateTextInput(textInput, eTextInput);
checkTextInputConstraints(eTextInput);
parent.addContent(eTextInput);
}
}
protected void populateTextInput(final TextInput textInput, final Element eTextInput) {
final String title = textInput.getTitle();
if (title != null) {
eTextInput.addContent(generateSimpleElement("title", title));
}
final String description = textInput.getDescription();
if (description != null) {
eTextInput.addContent(generateSimpleElement("description", description));
}
final String name = textInput.getName();
if (name != null) {
eTextInput.addContent(generateSimpleElement("name", name));
}
final String link = textInput.getLink();
if (link != null) {
eTextInput.addContent(generateSimpleElement("link", link));
}
}
protected void addItems(final Channel channel, final Element parent) throws FeedException {
final List<Item> items = channel.getItems();
for (int i = 0; i < items.size(); i++) {
addItem(items.get(i), parent, i);
}
checkItemsConstraints(parent);
}
protected void addItem(final Item item, final Element parent, final int index) throws FeedException {
final Element eItem = new Element("item", getFeedNamespace());
populateItem(item, eItem, index);
checkItemConstraints(eItem);
generateItemModules(item.getModules(), eItem);
parent.addContent(eItem);
}
protected void populateItem(final Item item, final Element eItem, final int index) {
final String title = item.getTitle();
if (title != null) {
eItem.addContent(generateSimpleElement("title", title));
}
final String link = item.getLink();
if (link != null) {
eItem.addContent(generateSimpleElement("link", link));
}
generateForeignMarkup(eItem, item.getForeignMarkup());
}
protected Element generateSimpleElement(final String name, final String value) {
final Element element = new Element(name, getFeedNamespace());
element.addContent(value);
return element;
}
protected void checkChannelConstraints(final Element eChannel) throws FeedException {
checkNotNullAndLength(eChannel, "title", 0, 40);
checkNotNullAndLength(eChannel, "description", 0, 500);
checkNotNullAndLength(eChannel, "link", 0, 500);
}
protected void checkImageConstraints(final Element eImage) throws FeedException {
checkNotNullAndLength(eImage, "title", 0, 40);
checkNotNullAndLength(eImage, "url", 0, 500);
checkNotNullAndLength(eImage, "link", 0, 500);
}
protected void checkTextInputConstraints(final Element eTextInput) throws FeedException {
checkNotNullAndLength(eTextInput, "title", 0, 40);
checkNotNullAndLength(eTextInput, "description", 0, 100);
checkNotNullAndLength(eTextInput, "name", 0, 500);
checkNotNullAndLength(eTextInput, "link", 0, 500);
}
protected void checkItemsConstraints(final Element parent) throws FeedException {
final int count = parent.getChildren("item", getFeedNamespace()).size();
if (count < 1 || count > 15) {
throw new FeedException("Invalid " + getType() + " feed, item count is " + count + " it must be between 1 an 15");
}
}
protected void checkItemConstraints(final Element eItem) throws FeedException {
checkNotNullAndLength(eItem, "title", 0, 100);
checkNotNullAndLength(eItem, "link", 0, 500);
}
}