fr.putnami.pwt.doc.client.rss.PwtDoucmentRssReader.java Source code

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Here is the source code for fr.putnami.pwt.doc.client.rss.PwtDoucmentRssReader.java

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/**
 * This file is part of pwt-doc.
 *
 * pwt-doc is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * pwt-doc is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with pwt-doc.  If not, see <http://www.gnu.org/licenses/>.
 */
package fr.putnami.pwt.doc.client.rss;

import java.util.Date;
import java.util.List;

import com.google.common.collect.Lists;
import com.google.gwt.http.client.Request;
import com.google.gwt.http.client.RequestBuilder;
import com.google.gwt.http.client.RequestCallback;
import com.google.gwt.http.client.RequestException;
import com.google.gwt.http.client.Response;
import com.google.gwt.i18n.client.DateTimeFormat;
import com.google.gwt.user.client.Cookies;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.xml.client.DOMException;
import com.google.gwt.xml.client.Document;
import com.google.gwt.xml.client.Element;
import com.google.gwt.xml.client.NodeList;
import com.google.gwt.xml.client.XMLParser;

public class PwtDoucmentRssReader {

    private final DateTimeFormat dateFormatter = DateTimeFormat.getFormat("EEE, d MMM yyyy");

    private final String rssUrl;

    public PwtDoucmentRssReader(String rssUrl) {
        this.rssUrl = rssUrl;
    }

    public void load(final AsyncCallback<List<RssItem>> callback) {
        RequestCallback requestCallback = new RequestCallback() {

            @Override
            public void onResponseReceived(Request request, Response response) {
                List<RssItem> items = Lists.newArrayList();
                try {
                    Document messageDom = XMLParser.parse(response.getText());

                    NodeList nodes = messageDom.getElementsByTagName("item");
                    for (int i = 0; i < nodes.getLength() && items.size() < 10; i++) {
                        Element item = (Element) nodes.item(i);
                        RssItem rssItem = new RssItem();
                        rssItem.setTitle(getStringValue(item, "title"));
                        rssItem.setDescription(getStringValue(item, "description"));
                        rssItem.setLink(getStringValue(item, "link"));
                        rssItem.setGuid(getStringValue(item, "guid"));
                        rssItem.setAuthor(getStringValue(item, "author"));
                        rssItem.setPubDate(getDateValue(item, "pubDate"));

                        boolean toAdd = true;

                        if (Cookies.isCookieEnabled()) {
                            String cookie = Cookies.getCookie(getCookieName(rssItem.getGuid()));
                            if (cookie != null && cookie.length() > 0) {
                                toAdd = false;
                            }
                        }
                        if (toAdd) {
                            items.add(rssItem);
                        }
                    }

                    callback.onSuccess(items);
                } catch (DOMException e) {
                    callback.onFailure(e);
                }
            }

            @Override
            public void onError(Request request, Throwable exception) {
                callback.onFailure(exception);
            }
        };
        RequestBuilder builder = new RequestBuilder(RequestBuilder.GET, this.rssUrl);
        builder.setCallback(requestCallback);
        try {
            builder.send();
        } catch (RequestException e) {
            callback.onFailure(e);
        }

    }

    private Date getDateValue(Element item, String tag) {
        String text = getStringValue(item, tag);
        if (text != null) {
            try {
                return dateFormatter.parse(text);
            } catch (IllegalArgumentException e) {
                return null;
            }
        }
        return null;
    }

    private String getStringValue(Element item, String tag) {
        String result = null;
        NodeList elements = item.getElementsByTagName(tag);
        if (elements.getLength() > 0) {
            result = elements.item(0).getFirstChild().getNodeValue();
        }
        return result;
    }

    private String getCookieName(String guid) {
        return "PWT_READ_NEWS:" + guid;
    }

    public void read(RssItem value) {
        if (Cookies.isCookieEnabled()) {
            Cookies.setCookie(getCookieName(value.getGuid()), new Date() + "");
        }
    }
}