Java tutorial
/* * Copyright 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.gwt.gdata.sample.hellogdata.client; import com.google.gwt.accounts.client.AuthSubStatus; import com.google.gwt.accounts.client.User; import com.google.gwt.event.dom.client.ClickEvent; import com.google.gwt.event.dom.client.ClickHandler; import com.google.gwt.gdata.client.DateTime; import com.google.gwt.gdata.client.GData; import com.google.gwt.gdata.client.GDataSystemPackage; import com.google.gwt.gdata.client.PhoneNumber; import com.google.gwt.gdata.client.atom.Text; import com.google.gwt.gdata.client.contacts.ContactEntry; import com.google.gwt.gdata.client.contacts.ContactFeed; import com.google.gwt.gdata.client.contacts.ContactFeedCallback; import com.google.gwt.gdata.client.contacts.ContactQuery; import com.google.gwt.gdata.client.contacts.ContactsService; import com.google.gwt.gdata.client.contacts.PersonEntry; import com.google.gwt.gdata.client.contacts.PersonEntryCallback; import com.google.gwt.gdata.client.impl.CallErrorException; import com.google.gwt.user.client.ui.Button; import com.google.gwt.user.client.ui.FlexTable; import com.google.gwt.user.client.ui.Label; import java.util.Date; /** * The following example demonstrates how to update a contact. */ public class ContactsUpdateContactDemo extends GDataDemo { /** * This method is used by the main sample app to obtain * information on this sample and a sample instance. * * @return An instance of this demo. */ public static GDataDemoInfo init() { return new GDataDemoInfo() { @Override public GDataDemo createInstance() { return new ContactsUpdateContactDemo(); } @Override public String getDescription() { return "<p>This sample demonstrates how to update a contact entry. " + "It obtains the first contact entry with a title starting with " + "'GWT-Contacts-Client' and updates its title.</p>"; } @Override public String getName() { return "Contacts - Updating contacts"; } }; } private ContactsService service; private FlexTable mainPanel; private final String scope = "http://www.google.com/m8/feeds/"; /** * Setup the Contacts service and create the main content panel. * If the user is not logged on to Contacts display a message, * otherwise start the demo by querying the user's contacts. */ public ContactsUpdateContactDemo() { mainPanel = new FlexTable(); initWidget(mainPanel); if (!GData.isLoaded(GDataSystemPackage.CONTACTS)) { showStatus("Loading the GData Contacts package...", false); GData.loadGDataApi(GDATA_API_KEY, new Runnable() { public void run() { startDemo(); } }, GDataSystemPackage.CONTACTS); } else { startDemo(); } } /** * Retrieves a contacts feed using a Query object. * In GData, feed URIs can contain querystring parameters. The * GData query objects aid in building parameterized feed URIs. * On success, obtain the first contact entry with a title starting * with "GWT-Contacts-Client", this is the contact that will be updated. * If no contact is found, display a message. * Otherwise call updateContact to update the contact. * * @param contactsFeedUri The contacts feed uri */ private void queryContacts(String contactsFeedUri) { showStatus("Querying contacts...", false); ContactQuery query = ContactQuery.newInstance(contactsFeedUri); Date today = new Date(); DateTime updatedMin = DateTime.newInstance(today, true); query.setUpdatedMin(updatedMin); query.setSortOrder(ContactQuery.SORTORDER_DESCENDING); service.getContactFeed(query, new ContactFeedCallback() { public void onFailure(CallErrorException caught) { showStatus("An error occurred while retrieving the Contacts feed: " + caught.getMessage(), true); } public void onSuccess(ContactFeed result) { ContactEntry[] entries = result.getEntries(); ContactEntry targetContact = null; for (ContactEntry contact : entries) { String title = contact.getTitle().getText(); if (title.startsWith("GWT-Contacts-Client")) { targetContact = contact; break; } } if (targetContact == null) { showStatus("No contacts were found that were modified today and " + "contained 'GWT-Contacts-Client' in the title.", false); } else { updateContact(targetContact); } } }); } /** * Displays a status message to the user. * * @param message The message to display. * @param isError Indicates whether the status is an error status. */ private void showStatus(String message, boolean isError) { mainPanel.clear(); mainPanel.insertRow(0); mainPanel.addCell(0); Label msg = new Label(message); if (isError) { msg.setStylePrimaryName("hm-error"); } mainPanel.setWidget(0, 0, msg); } /** * Update a contact by making use of the updateEntry * method of the Entry class. * Set the contact's title to an arbitrary string. Here * we prefix the title with 'GWT-Contacts-Client' so that * we can identify which contacts were updated by this demo. * We also update the contact's phone number. * On success and failure, display a status message. * * @param targetContact The contact entry which to update */ private void updateContact(ContactEntry targetContact) { targetContact.setTitle(Text.newInstance()); targetContact.getTitle().setText("GWT-Contacts-Client - updated contact"); PhoneNumber phoneNumber = PhoneNumber.newInstance(); phoneNumber.setValue("123-456-7890"); phoneNumber.setRel(PhoneNumber.REL_WORK); targetContact.setPhoneNumbers(new PhoneNumber[] { phoneNumber }); showStatus("Updating a contact event...", false); targetContact.updateEntry(new PersonEntryCallback() { public void onFailure(CallErrorException caught) { showStatus("An error occurred while updating a contact: " + caught.getMessage(), true); } public void onSuccess(PersonEntry result) { showStatus("Updated a contact.", false); } }); } /** * Starts this demo. */ private void startDemo() { service = ContactsService.newInstance("HelloGData_Contacts_UpdateContactDemo_v2.0"); if (User.getStatus(scope) == AuthSubStatus.LOGGED_IN) { Button startButton = new Button("Update a contact"); startButton.addClickHandler(new ClickHandler() { public void onClick(ClickEvent event) { queryContacts("http://www.google.com/m8/feeds/contacts/default/full"); } }); mainPanel.setWidget(0, 0, startButton); } else { showStatus("You are not logged on to Google Contacts.", true); } } }