GWT - AppDays - (25 aprile 2014, pordenone)

GWT-KickoffAlberto Mancini - Francesca Tosi

alberto@jooink.com - francesca@jooink.com

Kickoff

Alb

erto

alberto@jooink.com

http://github.com/jooink

http://www.jooink.com

http://jooink.blogspot.com

Fran

cesc

a

francesca@jooink.com

+FrancescaTosi

@francescatosi

http://github.com/jooink

http://www.jooink.com

http://jooink.blogspot.com

GD

G F

irenz

e

www.gdg-firenze.info

+GDG-Firenze

GW

T co

s’è

Google Web Toolkit (GWT) is an open source Java software development kit that makes writing AJAX applications like Google Maps and Gmail easy for developers.

http://www.gwtproject.org/

GW

T St

ats Official GWT Report by Vaadin

[2012] - https://vaadin.com/gwt-report-2012-portlet/download/1871870899/Future-of-GWT-Report-2012.pdf

[2013] - (del 10/04/2014 → GWT in crescita)https://vaadin.com/documents/10187/42fbbec4-51c8-426b-8aa8-fe46129353a3

GW

T St

ats

E’ uno fra i framework più

utilizzati

http://zeroturnaround.com/rebellabs/the-curious-coders-java-web-frameworks-comparison-spring-mvc-grails-vaadin-gwt-wicket-play-struts-and-jsf/

GW

T St

ats

Come viene principalmente

utilizzato

GW

T St

ats

Browser & platform support.

GW

T St

ats GWT è

molto usato in Europa

GW

T St

ats GWT

why i love it ;-)

GW

T St

ats GWT

the dark side

right

for ?

GW

T St

ats as of Q4/2012

● SDK downloaded over 1 million times● 100,000+ Active Developers● Deep Integration with Eclipse, IntelliJ, Spring STS/Roo● Used by Google products such as AdWords, Flights,

Wallet● Fun things: GwtQuake, Angry Birds for the Web● GWT Today is a mature, high quality, code base.

... n

ot a

Fra

mew

ork Frameworks that may help

https://github.com/ArcBees/GWTPmodel-view-presenter framework

http://www.jboss.org/erraiCDI, and JPA for GWT

http://www.tessell.org/app framework (on gwt-pectin)

Ecos

yste

mSencha’s GXT - http://www.sencha.com/products/gxt/

https://vaadin.com/gwt

http://code.google.com/p/smartgwt/

Why

Why?

FOSS

The GWT Steering committee was founded in 2012 to help the GWT project become an even bigger success as an open source project.

● Ray Cromwell, Google● Artur Signell, Vaadin● Colin Alworth, Sencha● Mike Brock, RedHat● Thomas Broyer● Stephen Haberman, Bizo● Daniel Kurka, Google● Christian Goudreau, Arcbees● Konstantin Solomatov, Jetbrains

Evol

ving

& M

atur

e Rev. Improvements

2006 GWT 1.0

2007 GWT 1.3/GWT 1.4 First Open Source Release, OSX support / JUnit and ImageBundle

2008 GWT 1.5 Java 1.5 support, Overlay Types, DOM API, CSS Themes, Linkers

2009 GWT 1.6/GWT 1.7GWT 2.0

EventHandlers, EMMA Support, WAR support, Parallelized Builds/Newer browser support, IE8, GPE and AppEngine/DevMode, DraftCompile, UIBinder, LayoutPanel, CodeSplitter, ClientBundle, CssResource

2010 GWT 2.1 RequestFactory, Editor Framework, Validation, MVP, Cell Widgets

2011 GWT 2.2/GWT 2.3GWT 2.4

GWT Designer, HTML5 support/Better AppEngine integration/Maven and RequestFactory enhancements

2012 GWT 2.5 SuperDevMode, Elemental, UiRenderers, FragmentMerging, ClosureCompiler

2013 GWT 2.5.1 ….

2014 GWT 2.6 ….

Bro

wse

rs

Bro

wse

rs

xché

una codebase e tante 'incarnazioni' dell'applicazione.

Bor

n to

be

...Why GWT? The beginnings of rich internet applications started taking off in 2004-2005 with Gmail/Google Maps. jQuery didn't even exist yet. There was a vacuum for tools to build large scale web applications, and leveraging the already mature Java toolchain of IDEs, libraries, build tools, testing frameworks, made good sense.

Ray Cromwell

Now

aday

s ● Plethora of languages compiling to js (..., python, C/C++, Ocaml, Haskel, ...)

● Good and awesome js libraries & frameworks

Closure Tools

Seco

ndo

noi

● non tutte le applicazioni sono uguali

● ed alle volte alcune richiedono strumenti inustitati

GW

T-B

oofc

vGWT-Boofcv sample at:http://goo.gl/3IJQgs

DEM

O

http://picshare.jooink.com

Mar

ker B

ased

AR

http://code.google.com/p/gwt-webgl/http://code.google.com/p/gwt-nyartoolkit/

http://picshare.jooink.com

Mob

ile (&

tab)

too

Com

e Fu

nzio

na

<video/>

<canvas/>

http://code.google.com/p/gwt-nyartoolkit/

Ny

HTTP

java

→ G

WT

Using Java libraries into the browser

JS →

GW

T

Using js libraries with java

Dee

per

Deeper.

GW

TGWT is a toolkit to develop Ajax web application with Java.

The programmer writes Java code and this code is translated into HTML and Javascript via the GWT compiler.

The compiler creates browser specific HTML and JavaScript to support all the major browsers correctly.

Tool

s in

the

Tool

kit

+ GWTc, compiler Java to Javascript+ Emulated JRE+ Web UI class library (Widgets)+ Eclipse Plugin, SpeedTracer, Designer

It's open source, completely free, and used by thousands of developers around the world (in Google AdWords,Orkut,Blogger,Groups)

Com

pile

r GWT compiler

● java to javascript optimizing compiler

● translates java AST into js AST

● splits code into fragments to improve loading performance

Link

er● responsible for the final form of the generated js

xsiframe is the standard one

there are linkers for generating web-workers, gadgets, chrome extensions, …

defe

rred

bin

ding

Deferred Binding:feature of the GWT compiler that works by generating many versions of code at compile time, only one of which needs to be loaded by a particular client during bootstrapping at runtime.

Each version is generated on a per browser basis, along with any other axis that your application defines or uses.

RPC CallsWidgets tuned for specific browsersInternationalization

defe

rred

bin

ding

Deferred binding has several benefits:

● Reduces the size of the generated JavaScript code (downloaded by each client) - including just the code needed to run the browser/locale instance (used by the Internationalization

module)● Automatic generation of code (saving development time) to

implement an interface or create a proxy class (used by the

GWT RPC module)● Since the implementations are pre-bound at compile time,

there is no run-time penalty to look up an implementation in a data structure as with dynamic binding or using virtual functions.

Emul

ated

JR

EGWT includes a library that emulates a subset of the Java runtime library.

http://www.gwtproject.org/doc/latest/RefJreEmulation.html

InputStream

Threads ?

JNSI GWT borrows from the Java Native Interface (JNI) concept to

implement JavaScript Native Interface (JSNI).

Writing JSNI methods is a powerful technique, but should be used sparingly because writing bulletproof JavaScript code is notoriously tricky.

Needed for JSO (Javascript Overlay Types)

JNSI

public static native void alert(String msg) /*-{ $wnd.alert(msg);}-*/;

$wnd: the root browser window GWT widgets are being rendered to

$entry(..): method that makes code reentry safe.

http://www.lustforge.com/2012/11/11/gwt-jsni-variables-an-exhaustive-list/http://www.gwtproject.org/doc/latest/DevGuideCodingBasicsJSNI.html

Wid

gets UiComponents

http://www.gwtproject.org/doc/latest/RefWidgetGallery.html

2.0+ LayoutPanelshttp://www.gwtproject.org/doc/latest/DevGuideUiPanels.html#LayoutPanels

from the Jul 2013 - GWT Meetup

What are some of pain points or decisions bad in hindsight?...● Bad out of box UI

...

SmartGWT, GXT

UiB

inde

r ● The UiBinder is a framework designed to separate Functionality and View of User Interface.

● The UiBinder framework allows developers to build gwt applications as HTML pages with GWT widgets configured throughout them.

● The UiBinder framework makes easier collaboration with UI designers who are more comfortable with XML, HTML and CSS than Java source code

● The UIBinder provides a declarative way of defining (parts of the) User Interface.

● The UIBinder seperates the programmic logic from UI.

● The UIBinder is similar to what JSP is to Servlets.

UiB

inde

r● DSL (xml) to lay-out (declaratively) widgets

● no loops, no conditionals, no if statements

● UiBinder allows you to lay out your user interface.

● (offers direct support for internationalization)

GW

T - R

PC

Lets the client and the server to exchange java objects over http.

Bat

tlePl

an Domani:

● Codelab 2h: GWT mobile app10:30 → 12:30

● Codelab 4h: GWT hands-on14:00 → 18:00

Than

ks

Alberto Mancinialberto@jooink.com

Francesca Tosifrancesca@jooink.com