Advanced Web Technology 5) Google Web Toolkits - GWT, Client Side

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1 Advanced Web Technology 5) Google Web Toolkits - GWT, Client Side Emmanuel Benoist Spring Term 2018 Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 1

2 Table of Contents Presentation of GWT Hello World Application Widgets Hello World Event Handling Applying Style Sheets Deployment Internationalization Static String i18n Remote Procedure Code JSON Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 2

3 Presentation of GWT Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 3

4 Motivation What is GWT? A development environment in pure Java for rich web applications Provides Java for programming both client and server sides Advantages of GWT Homogenous environment Testing of a web application (using JUnit) Not integrated in JSF Concurent system developed by google Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 4

5 Principle Write Java code Use Java on Server Side But also on a Client Side Communication is handeled conveniently Tests in a JVM Testing is done using JUnit Plugin in the browser Tests are conducted inside one JVM (based on Java Code) Compile into Javascript Creates different versions for different browsers Each browser receives only the right version Can be deployed on Java Servers Or any other server (if the server part is not Java) Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 5

6 Hello World Application Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 6

7 Hello World Application Download the GWT From Google Code Web site Create an application Execute./webAppCreator -out /home/bie1/test/ ch.bfh.awt.hello A default application is created Includes ant and Eclipse project files Test the Application Go to the directory execute ant devmode Install the plugin in your browser Test the application Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 7

8 Directories created Source files: /src/ Package for client side application : /src/ch/bfh/awt/client Server side classes : /src/ch/bfh/awt/server The file /src/ch/bfh/awt/hello.gwt.xml contains the configurations for the GWT application Web Application: /war/ Contains html, css, javascript, gifs, and the like Contains the WEB-INF/ directory (where the server classes are automatically compiled The directory /war/ will receive the JavaScript files compiled from the client application At the end the content of this directory is copied to the server Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 8

9 Widgets Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 9

10 Hello World Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 10

11 Hello World Hello.html: contains a real HTML Containing layout, References to images, JavaScript, CSS Reference to the script loading the files <script type="text/javascript" language="javascript" src=" hello/hello.nocache.js"></script> And it contains place-holders that will be manipulated from Java. <div id="namefieldcontainer"></div> <div id="sendbuttoncontainer"></div> <div style="color:blue;" id="responsecontainer" ></div> Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 11

12 HTML FIle <!doctype html> <html> <head> <meta http equiv="content type" content="text/html; charset=utf 8"> <link type="text/css" rel="stylesheet" href="hello.css"> <title>web Application Starter Project</title> <script type="text/javascript" language="javascript" src="hello/hello. nocache.js"></script> </head> <body>... <h1>web Application Starter Project</h1> Please enter your name: <div id="namefieldcontainer"></div> <div id="sendbuttoncontainer"></div> <div style="color:blue;" id="responsecontainer"></div> </body> </html> Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 12

13 Java File Contains the definition of the user interface Definition of the Widgets used, Panels, Text fields, buttons Extends the EntryPoint class Defines the onmoduleload() function. Defines the Event Handling Defines functions to be executed when an Event is fired. Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 13

14 Hello.java package ch.bfh.awt.client; import... / Entry point classes define <code>onmoduleload()</code>. / public class Hello implements EntryPoint { public void onmoduleload() { final Button sendbutton = new Button("Send"); final TextBox namefield = new TextBox(); final Label responselabel = new Label(); RootPanel.get("nameFieldContainer").add(nameField); RootPanel.get("sendButtonContainer").add(sendButton); RootPanel.get("responseContainer").add(responseLabel); namefield.setfocus(true);... // Event Handling Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 14

15 Widgets List of default widgets Buttons: Button, PushButton, RadioButton,CheckBox,,, Calendar: DatePicker Lists : ListBox, CellList, Trees: MenuBar, Tree with CellTree, Panels: PopoupPanel, StackPanel, HorizontalPanel, VerticalPanel, latest/refwidgetgallery.html Possibility to write your own widgets: latest/devguideuicustomwidgets.html Composite components (composition of existing components) or from scratch in Java code Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 15

16 Example: StockWatcher 1 An interface to watch stock values Presentation (when deployed on localhost) localhost:8080/stockwatchergwt User Interface: One page One page A list containing the stocks A field to type the stock into A button to add a new stock Back-office No back-office today Communications with the servers are seen in the next course Communication available: Remote Procedure Call (RPC) in Java Call to JSON data on the same server (PHP for instance) Call to JSON data on another server (against the same origin policy). 1 Source:http: //code.google.com/intl/fr-fr/webtoolkit/doc/latest/tutorial/ Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 16

17 The HTML Page 2 <body> <img src="images/bfh.jpg" /> <h1>stock Watcher testing project</h1> <div id="stocklist"></div> <iframe src="javascript: " id=" gwt_historyframe" tabindex= 1 style="position:absolute;width:0;height:0;border:0"></iframe> <noscript> <div style="width: 22em; position: absolute; left: 50%; margin left : 11em; color: red; background color: white; border: 1px solid red; padding: 4px; font family: sans serif"> Your web browser must have JavaScript enabled in order for this application to display correctly. </div> </noscript> </body> 2 /war/stockwatcher.html Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 17

18 Java Files 3 Contains Widgets mainpanel a vertical panel containing components addpanel an horizontal panel containing a textbox and a button stocksflextable a fexible table containing lines and columns newsymboltextbox a text box to enter text into addstockbutton a button that generates an event when clicked on lastupdatedlabel a label contains a text private VerticalPanel mainpanel = new VerticalPanel(); private FlexTable stocksflextable = new FlexTable(); private HorizontalPanel addpanel = new HorizontalPanel(); private TextBox newsymboltextbox = new TextBox(); private Button addstockbutton = new Button("Add"); private Label lastupdatedlabel = new Label(); 3 /src/ch/bfh/awt/client/stockwatcher.java Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 18

19 The Java File public void onmoduleload() { // Create table for stock data. stocksflextable.settext(0, 0, "Symbol"); stocksflextable.settext(0, 1, "Price"); stocksflextable.settext(0, 2, "Change"); stocksflextable.settext(0, 3, "Remove"); // Assemble Add Stock panel. addpanel.add(newsymboltextbox); addpanel.add(addstockbutton); // Assemble Main panel. mainpanel.add(stocksflextable); mainpanel.add(addpanel); mainpanel.add(lastupdatedlabel); // Associate the Main panel with the HTML host page. RootPanel.get("stockList").add(mainPanel); // Move cursor focus to the input box. newsymboltextbox.setfocus(true); Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 19

20 Event Handling Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 20

21 Event Handling Events Handlers are attached to widgets Events in GWT use the event handler interface model similar to other user interface frameworks. To subscribe to an event, you pass a particular event handler interface to the appropriate widget. An event handler interface defines one or more methods that the widget then calls to announce (publish) an event. Example: Hello World Add an event handler for a click on the button Add an event handler when a user types on the Enter key Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 21

22 Event Handlers for Hello World 4 class MyHandler implements ClickHandler, KeyUpHandler { public void onclick(clickevent event) { copyname(); public void onkeyup(keyupevent event) { if (event.getnativekeycode() == KeyCodes.KEY_ENTER) { copyname(); private void copyname() { String texttocopy = namefield.gettext(); responselabel.settext(texttocopy); MyHandler handler = new MyHandler(); sendbutton.addclickhandler(handler); namefield.addkeyuphandler(handler); 4 Inside the definition of the class Hello Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 22

23 Event Handling by Stock Watcher // Listen for mouse events on the Add button. addstockbutton.addclickhandler(new ClickHandler() { public void onclick(clickevent event) { addstock(); ); // Listen for keyboard events in the input box. newsymboltextbox.addkeypresshandler(new KeyPressHandler() { public void onkeypress(keypressevent event) { if (event.getcharcode() == KeyCodes.KEY_ENTER) { addstock(); ); private void addstock() { // TODO Auto generated method stub Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 23

24 Manipulate the content of the Widgets Java can generate an alert(). Window.alert(" " + symbol + " is not a valid symbol."); One can manipulate elements in a list int removedindex = stocks.indexof(symbol); stocks.remove(removedindex); stocksflextable.removerow(removedindex + 1); Or change the text of a label or a text box private void copyname() { // First, we validate the input. String texttocopy = namefield.gettext(); responselabel.settext(texttocopy); or Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 24

25 Applying Style Sheets Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 25

26 Applying Style Sheets Configure the standard theme standard.css : contains the GWT default styles (themes) In GWT config file : Hello.gwt.xml Defines the theme: <inherits name= com.google.gwt.user.theme.standard. Standard /> <! <inherits name="com.google.gwt.user.theme. chrome.chrome"/> > <! <inherits name="com.google.gwt.user.theme.dark. Dark"/> > Associate a CSS file Hello.css : contains the project specific classes Linked inside the Hello.html <link type="text/css" rel="stylesheet" href="hello.css"> Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 26

27 Add Style to the elements Suppose we have the following style: / stock list header row /.watchlistheader { background color: #2062B8; color: white; font style: italic; / stock list flex table /.watchlist { border: 1px solid silver; padding: 2px; margin bottom:6px; Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 27

28 Add Style to the elements (Cont.) We add style to the elements of the first row of the table // Add styles to elements in the stock list table. stocksflextable.getrowformatter().addstylename(0, " watchlistheader"); Format all the elements of a table stocksflextable.addstylename("watchlist"); Or format only one cell stocksflextable.getcellformatter().addstylename(0, 1, " watchlistnumericcolumn"); Or even a panel addpanel.addstylename("addpanel"); Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 28

29 Deployment Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 29

30 Deployment Compile the application into JavaScript Using GWT Compile Project button in Eclipse Or executing ant build Compilation writes all the required files in the War directory Uses the definition files and all the existing files in the war/ (html, gif, images, css,... ) Copy the content of the directory To a servlet engine if you use the server side functionality To any server if using only the client side Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 30

31 Internationalization Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 31

32 Internationalization : I18N Module Core types related to internationalization: LocaleInfo Provides information about the current locale. Constants Useful for localizing typed constant values Messages Useful for localizing messages requiring arguments ConstantsWithLookup Like Constants but with extra lookup flexibility for highly data-driven applications Dictionary Useful when adding a GWT module to existing localized web pages Localizable Useful for localizing algorithms encapsulated in a class or when the classes above don t provide sufficient control DateTimeFormat Formatting dates as strings. See the section on date and number formatting. NumberFormat Formatting numbers as strings. See the section on date and number formatting. Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 32

33 Static String i18n Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 33

34 Interantionalizing Strings Implement the Constant Interface Contains only static strings Very efficient and compiled once. Implement the Messages Interface Allows to insert values in the string For instance numbers or dates Equivalent to the resource bundle in applications. Dynamic String Internationalization The Dictionary class lets your GWT application consume strings supplied by the host HTML page. Convenient if your existing web server has a localization system that you do not wish to integrate with the static string internationalization methods. Implement the Localizable Interface The most powerful technique allows you to go beyond simple string substitution create localized versions of custom types. Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 34

35 Implement the Constants Interface Create the StockWatcherConstants interface Uses annotations for the default translation Implements the Constant interface (GWT) Bound automatically to the StockWatcherConstants*.properties files The java file must contain one method for each of the constants in the properties files The right value is found at runtime, corresponding to the locale Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 35

36 Example: the Constants file package com.google.gwt.sample.stockwatcher.client; import com.google.gwt.i18n.client.constants; public interface StockWatcherConstants extends Constants String String String String String String add(); Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 36

37 Translate it to German Create a file StockWatcherConstants_de.properties stockwatcher = Aktienbeobachter symbol = Symbol price = Kurs change = Änderung remove = Entfernen add = Hinzufügen Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 37

38 Implement the Messages interface For Strings containing information Similar to resource bundles in Java Can contain strings with parameters {0 ist kein gültiges Aktiensymbol. The number is a place holder mystring = First parm is {0, second parm is {1, third parm is {2. Usefull for integrating dates, prices, internationalized results Usefull but less efficient. The strings must be produced at runtime Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 38

39 Messages file package com.google.gwt.sample.stockwatcher.client; import com.google.gwt.i18n.client.messages; import java.util.date; public interface StockWatcherMessages extends Messages {0 is not a valid symbol.") String invalidsymbol(string update: {0,date,medium {0,time, medium") String lastupdate(date timestamp); Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 39

40 The corresponding properties file StockWatcherMessages_de.properties file. lastupdate = Letzte Aktualisierung: {0,date,medium {0,time, medium invalidsymbol = {0 ist kein gültiges Aktiensymbol. Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 40

41 Replace content Replace the texts with place holders <body> <img src="images/googlecode.png"/> <h1 id="apptitle"></h1> Replacing strings set programmatically Create the instances of the classes (internationalized) private ArrayList<String> stocks = new ArrayList<String>(); private StockWatcherConstants constants = GWT.create( StockWatcherConstants.class); private StockWatcherMessages messages = GWT.create( StockWatcherMessages.class); Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 41

42 Replace content (Cont) Set the content: // Set the window title, the header text, and the Add button text. Window.setTitle(constants.stockWatcher()); RootPanel.get("appTitle").add(new Label(constants. stockwatcher())); addstockbutton = new Button(constants.add()); // Create table for stock data. stocksflextable.settext(0, 0, constants.symbol()); stocksflextable.settext(0, 1, constants.price()); stocksflextable.settext(0, 2, constants.change()); stocksflextable.settext(0, 3, constants.remove()); Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 42

43 Add a supported locale: Inside StockWatcher.gwt.xml add the property <entry point class= com.google.gwt.sample.stockwatcher.client.stockwatcher /> <extend property name="locale" values="de"/> </module> Load the german version by adding &locale=de Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 43

44 Client Server Communication Remote Procedure Code From Java To Java Supported by the language Optimized and easy to test JSON For communicating with the same server JSONP For cross server communication Overgoes the Same Origin Policy Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 44

45 Remote Procedure Code Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 45

46 GWT Remote Procedure Call RPC contains: the service that runs on the server the method you are calling the client code that invokes the service the Java data objects that pass between the client and server Both (client and server) must serialize and deserialize the objects You need to write three components Define the interface StockPriceService that extends RemoteService and lists all your RPC methods Create a class StockPriceServiceImpl that extends RemoteServiceServlet and implements the interface you created above. Define an asynchronous interface StockPriceServiceAsync to your service to be called from the client-side code. Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 46

47 GWT Remote Procedure Call 5 5 Source: code.google.com Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 47

48 StockPriceService interface In the package com.google.gwt.sample.stockwatcher.client package com.google.gwt.sample.stockwatcher.client; import com.google.gwt.user.client.rpc.remoteservice; import com.google.gwt.user.client.rpc.remoteservicerelativepath public interface StockPriceService extends RemoteService { StockPrice[] getprices(string[] symbols); Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 48

49 StockPriceServiceImpl class package com.google.gwt.sample.stockwatcher.server; import com.google.gwt.sample.stockwatcher.client.stockprice; import com.google.gwt.sample.stockwatcher.client.stockpriceservice; import com.google.gwt.user.server.rpc.remoteserviceservlet; import java.util.random; public class StockPriceServiceImpl extends RemoteServiceServlet implements StockPriceService { private static final double MAX_PRICE = 100.0; // $ private static final double MAX_PRICE_CHANGE = 0.02; // +/ 2% public StockPrice[] getprices(string[] symbols) { Random rnd = new Random(); StockPrice[] prices = new StockPrice[symbols.length]; for (int i=0; i<symbols.length; i++) { double price = rnd.nextdouble() MAX_PRICE; double change = price MAX_PRICE_CHANGE (rnd.nextdouble () 2f 1f); prices[i] = new StockPrice(symbols[i], price, change); return prices; Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 49

50 Include the server-side code in the GWT module Define new servlets in the web.xml <web app> <welcome file list> <welcome file>stockwatcher.html</welcome file> </welcome file list> <servlet> <servlet name>stockpriceserviceimpl</servlet name> <servlet class>com.google.gwt.sample.stockwatcher.server. StockPriceServiceImpl</servlet class> </servlet> <servlet mapping> <servlet name>stockpriceserviceimpl</servlet name> <url pattern>/stockwatcher/stockprices</url pattern> </servlet mapping> </web app> Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 50

51 Invoking the service from the client Making asynchronous calls to the server package com.google.gwt.sample.stockwatcher.client; import com.google.gwt.user.client.rpc.asynccallback; public interface StockPriceServiceAsync { void getprices(string[] symbols, AsyncCallback<StockPrice[]> callback); Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 51

52 Making the remote procedure call private void refreshwatchlist() { // Initialize the service proxy. if (stockpricesvc == null) { stockpricesvc = GWT.create(StockPriceService.class); // Set up the callback object. AsyncCallback<StockPrice[]> callback = new AsyncCallback< StockPrice[]>() { public void onfailure(throwable caught) { // TODO: Do something with errors. public void onsuccess(stockprice[] result) { updatetable(result); ; // Make the call to the stock price service. stockpricesvc.getprices(stocks.toarray(new String[0]), callback); Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 52

53 Serializing Java objects GWT RPC requires that all service method parameters and return types be serializable. package com.google.gwt.sample.stockwatcher.client; import java.io.serializable; public class StockPrice implements Serializable { private String symbol; private double price; private double change;... Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 53

54 JSON Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 54

55 Retrieving JSON Data JSON stands for JavaScript Object Notation Language independant format Very light Example [ { "symbol": "ABC", "price": 87.86, "change": 0.41, { "symbol": "DEF", "price": 62.79, "change": 0.49 ] Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 55

56 Server part JSON can be generated by a servlet out.println(" {"); out.print(" \"symbol\": \""); out.print(stocksymbol); out.println("\","); out.print(" \"price\": "); out.print(price); out.println(, ); out.print(" \"change\": "); out.println(change); out.println(","); Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 56

57 JSON generated by PHP <?php header( Content Type: text/javascript ); define("max_price", 100.0); // $ define("max_price_change", 0.02); // +/ 2% echo [ ; $q = trim($_get[ q ]); if ($q) { $symbols = explode(, $q); for ($i=0; $i<count($symbols); $i++) { $price = lcg_value() MAX_PRICE; $change = $price MAX_PRICE_CHANGE (lcg_value() ); echo { ; echo "\"symbol\":\"$symbols[$i]\","; echo "\"price\":$price,"; echo "\"change\":$change"; echo ; if ($i < (count($symbols) 1)) { echo, ; Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 57

58 Transform JSON object into JavaScript use the built in JavaScript function eval The function will receive a response.gettext() as a parameter private final native JsArray<StockData> asarrayofstockdata( String json) / { return eval(json); /; Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 58

59 Manipulate JSON objects Create a JavaScriptObject StockData to manipulate the data input in Java package com.google.gwt.sample.stockwatcher.client; import com.google.gwt.core.client.javascriptobject; class StockData extends JavaScriptObject { // Overlay types always have protected, zero argument constructors. protected StockData() { // JSNI methods to get stock data. public final native String getsymbol() / { return this.symbol; /; public final native double getprice() / { return this.price; /; public final native double getchange() / { return this.change; /; // Non JSNI method to return change percentage. public final double getchangepercent() { return getchange() / getprice(); Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 59

60 Connect the Web server Prepare the list of stocks private void refreshwatchlist() { if (stocks.size() == 0) { return; String url = JSON_URL; // Append watch list stock symbols to query URL. Iterator iter = stocks.iterator(); while (iter.hasnext()) { url += iter.next(); if (iter.hasnext()) { url += "+"; url = URL.encode(url); // TODO Send request to server and handle errors. Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 60

61 Connect the Web Server (Cont.) // Send request to server and catch any errors. RequestBuilder builder = new RequestBuilder(RequestBuilder.GET, url); try { Request request = builder.sendrequest(null, new RequestCallback() { public void onerror(request request, Throwable exception) { displayerror("couldn t retrieve JSON"); public void onresponsereceived(request request, Response response ) { if (200 == response.getstatuscode()) { updatetable(asarrayofstockdata(response.gettext())); else { displayerror("couldn t retrieve JSON (" + response. getstatustext() + ")"); ); catch (RequestException e) { displayerror("couldn t retrieve JSON"); Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 61

62 Conclusion GWT: pure Java Web Application Client and Server share one language Testing made easy Testing of Web Application is often a nightmare JUnit testing is possible Debugging inside one JVM : In Eclipse or in devmode Security? What is executed where? What is transfered and can be manipulated? What is tested where? Useful features I18N Client Server Communication Remote Procedure Call JSON Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 62

63 References Tutorial by Google Code fr-fr/webtoolkit/overview.html latest/tutorial/gettingstarted.html Developer Guide by Google Code latest/devguide.html Hello World Example Obtained by executing the create application script. Tutorial for Client Server communication latest/tutorial/clientserver.html Berner Fachhochschule Haute école spécialisée bernoise Berne University of Applied Sciences 63

Berner Fachhochschule Haute cole spcialise bernoise Berne University of Applied Sciences 2

Berner Fachhochschule Haute cole spcialise bernoise Berne University of Applied Sciences 2 Table of Contents Advanced Web Technology 13) Google Web Toolkits 2 - GWT, Communication Emmanuel Benoist Fall Term 2016-17 Internationalization Static String i18n Remote Procedure Code JSON Berner Fachhochschule