GWT@Jazoon08 - Part 3/6 - Personalization & Customization

LOGO SPEAKER‘S COMPANY

# 3

personalizationand customization.


identify yourself with the product ...


the barmaid remembering your favourite drink ...


customize your drink at Starbucks ...


+6.6 billion people can’t all be the same ...


+/- 191 currencies ...


let’s meet on 01/02/2008 ...

LOGO SPEAKER‘S COMPANYcan you pick me up at 9 o’clock ...


annoying.

my favourite application doesn’t run in an OpenSocial container nor on my IPhone nor does it have offline access


linker.[ overview ]


linker.“In computer science, a linker is a program

that takes one or more objects generated by the compiler and assembles them into a single executable program.”

- Wikipedia


objectobject objectobject objectobject

linker

iPhoneiPhoneAdobe Air

Adobe Air AndroidAndroidGearsGearsOpen

Social

OpenSocial


PRIMARY LINKERS

the primary linker is responsible for module bootstrap

pre- and post-linkers run before and after the primary Linker

linkers are only run during web-mode compile

SelectionScriptLinker // Bootstrap is an external script

HostedModeLinker // Only for hosted mode

XSLinker // Cross site linker

SingleScriptLinker // Provides single JS file

IFrameLinker [default] // Loads JS in Iframe

@LinkerOrder(Order.PRIMARY)

public class IFrameLinker extends SelectionScriptLinker { … }


ENABLE AN EXISTING LINKER

<add-linker name=“std”/> IFrame linker

<add-linker name=“xs”/> Cross site linker

<add-linker name=“sso”/> Single script linker


ARTIFACTS

Linker operate on a set of Artifacts:

CompilationResult // unique chunk of JavaScript permutation

EmittedArtifact // emitted to output directory

GeneratedSource // GeneratorContext.tryCreateResource

PublicResource // files in public path

SyntheticArtifact // created by Linker

ScriptReference // external script ref. in .gwt.xml

StylesheetReference // external CSS ref. in .gwt.xml

Communicate with Linker stack via GeneratorContext.commitArtifact();

Linkers can transform one ArtifactSet into another

LinkerContext contains global data (module name, selection properties…)


linker.[ build your own linker ]


customize.synthesize additional output-dependent files Google Gears ManagedResourceStore manifest file

integrate with other environments iGoogle, OpenSocial …

provide an alternate bootstrap or packaging Gadgets and single stage bootstraps

generally solve “GWT and … “ integration


BUILD YOUR OWN LINKER (1/2)

@LinkerOrder(Order.POST)

public class FileListLinker extends AbstractLinker {

public ArtifactSet link(TreeLogger logger, LinkerContext context,

ArtifactSet artifacts) throws UnableToCompleteException {

ArtifactSet toReturn = new ArtifactSet(artifacts);

toReturn.add(createFileListArtifact(toReturn));

return toReturn;

}


BUILD YOUR OWN LINKER (2/2)

public Artifact createFileListArtifact(ArtifactSet toReturn) {

SortedSet<EmittedArtifact> emitted = toReturn.find(EmittedArtifact.class);

StringBuffer fileList = new StringBuffer(“<html><body>”);

for (EmittedArtifact artifact : emitted) {

fileList.append(artifact.toString() + “<br/>”);

}

fileList.append(“</body></html>”);

return emitBytes(logger, Util.getBytes(fileList.toString()), "fileList.html“));

}


DEFINE THE NEW LINKER

<define-linker name=“fileListLinker" class=“com.FileListLinker" />

ENABLE THE NEW LINKER

<add-linker name=“fileListLinker”/>


linker.[ advanced use case ]


INLINE SELECTION SCRIPT INTO HOST PAGE (1/2)

public ArtifactSet link(TreeLogger logger, LinkerContext

context, ArtifactSet artifacts) throws UnableToCompleteException {

artifacts = new ArtifactSet(artifacts);

EmittedArtifact script = getSelectionScript(artifacts); artifacts.remove(script);

for (EmittedArtifact e : artifacts.find(EmittedArtifact.class)) {

if (e.getPartialPath().toLowerCase().endsWith(".html")) {

EmittedArtifact newArtifact = replaceScripts(logger, e, script);

artifacts.replace(newArtifact); } } return artifacts;

}


INLINE SELECTION SCRIPT INTO HOST PAGE (2/2)

private EmittedArtifact replaceScript(TreeLogger logger,

EmittedArtifact e, EmittedArtifact script) throws

UnableToCompleteException {

String page = Util.readStreamAsString(e.getContents(logger));

// ... replacements happen ... EmittedArtifact toReturn = emitString(logger, page,

e.getPartialPath()); return toReturn;

}


localization.[ for dummies ]


CREATE INTERFACE TO DEFINE TYPE-SAFE TEMPLATES

public interface ErrorMessages extends Messages {

String accessDenied(int code, String userName);

}

CREATE CORRESPONDING PROPERTY FILE

accessDenied=Error {0}: {1} cannot access {2}


ADD LOCALE CHOICES TO A MODULE

<module> <inherits name=“com.google.gwt.i18n.I18N”/> <extend-property name=“locale” values=“fr”/> </module>

APPLY MESSAGE

ErrorMessages msgs = GWT.create(ErrorMessages.class);

Window.alert(msgs.accessDenied(502, username));


CHOOSE A LOCALE AT RUNTIME

url based: http://localhost:808/example?locale=nl meta tag: <meta name=“gwt:property” content=“locale=fr”>

OTHER LOCALE OPTIONS

messages = templated messages constants = simple messages withLookup = extra lookup functionality dictionary = for locale data encapsulated in the page [runtime]


localization.[ demystified ]


CODE GENERATION

a Java source file is generated for each defined language generation is based upon the Localizable interface at runtime a property provider determines the locale based upon the ‘locale=nl’ URL argument or Meta property

no data structure in the middle no runtime loading or resolution they work because they passed the compiler format must be UTF-8 locale fallback mechanism en_US -> en -> default DateTime and NumberFormat have local backend-in


COMPILER OPTIMIZATION

MyConstants constants = GWT.create(MyConstants.class); String hello = constants.hello(); Window.alert(hello);

compiles into:

$intern_2 = ‘hello’; $wnd.alert($intern_2);

and not into:

$wnd.alert(‘hello’); // some browsers actually create a new literal object


localization.[ real life issues ]


DYNAMIC LOCALES

locales tend to change many use cases include database driven locales

so how do we deal with runtime changing locales????

options

- locale data stored in project locale files recompile

- locale data stored in database extract to project locale files + recompile (Thread changes as bugs)

reload page + embed new locales in HTML file + Dictionary support runtime locales in the client


DYNAMIC LOCALES

runtime locales in the client

Label aLabel = new Label(); // HasText

LocaleSupport.addListener(aLabel); // Updates all HasText on locale change

there goes the lazy developer .. let’s think …

But how does the LocaleSupport know that a locale has been updated? - server needs to figure out what to do ??? state on the server - poll at regular interval - piggy bagging - do I lock the client while I update all the labels ??? - or do I only update the current labels and updates the others later ??? - so the client needs to download this complete update mechanism


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GWT@Jazoon08 - Part 3/6 - Personalization & Customization

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Transcript of GWT@Jazoon08 - Part 3/6 - Personalization & Customization