Internationalization and the Java StackPart 2

Matt Wheeler

Notes

• This is a training NOT a presentation• Please ask questions• Prerequisites

– Introduction to Java Stack– Introduction to Spring– Basic Java and XML skills– Internationalization and the Java Stack Part 1– Installed LdsTech IDE (or other equivalent)

Overview

• Stack provided internationalization tools• Message source expression language resolver• JS Message Source• RequireJS Message Source

• Internationalization best practices• Internationalization testing

• Dynamic pseudo translation

Expression Language Resolver

• Provided message resolver can be utilized in EL

• http://code.lds.org/maven-sites/stack/module.html?module=web-spring/#El_Message_Source

<%@ taglib prefix="web-spring" uri="http://code.lds.org/web/spring" %>

<!-- This makes the internationalized properties of the default MessageSource available as a map in the specified scope--><web-spring:message-source var="messages" scope="request"/>

<!- Reference the messages in EL by key -->${messages['abc.def.ghi']}

JavaScript MessageSource

• Configuration<bean id="messageSource" class="org.lds.stack.web.spring.i18n.message.EnumeratableMessageSourceImpl"> <property name="basenames"> <list> <value>classpath:messages</value> </list> </property></bean>

<bean id="messageSourceController" class="org.lds.stack.web.spring.i18n.MessageSourceController"> <property name="messageSource" ref="messageSource" /></bean>

<!-- Create adapter to handle all non-annotation controllers --><bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"/>

<!-- Map the properties url to the controller --><bean class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping"> <property name="mappings"> <props> <prop key="/messageSource.js">messageSourceController</prop> </props> </property> <property name="order" value="#{T(org.springframework.core.Ordered).HIGHEST_PRECEDENCE}"/></bean>

MessageSource with JS

• Usage in a JSP page<script charset="utf-8" src="${pageContext['request'].contextPath}/messageSource.js" type="text/javascript"></script>

<!– This effectively writes out the following variable in JavaScript containing key value pairs for everything in the MessageSource, for use as follows -->

var msgs = { "index.welcome":"Welcome", "accessDenied.accessdenied":"Access Denied", "def":"{0} asdfa asdfasd {1} asdfasd asdf ", "index.mainpage":"Main page - {0}“};

<script type="text/javascript"> alert(msgs['index.welcome']);</script>

RequireJS MessageSource

• Configuration<bean id="messageSource" class="org.lds.stack.web.spring.i18n.EnumeratableMessageSourceImpl"> <property name="basenames"> <list> <value>classpath:messages</value> </list> </property></bean>

<bean id="messageSourceController" class="org.lds.stack.web.spring.i18n.RequireJsMessageSourceController"> <property name="messageSource" ref="messageSource"/> <property name="replaceDotsInKeys" value="true"/></bean>

<!-- Create adapter to handle all non-annotation controllers --><bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"/>

<!-- Map the properties url to the controller --><bean class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping"> <property name="urlMap"> <map> <entry key="/js/nls/messages.js" value-ref="messageSourceController"/> <entry key="/js/nls/*/messages.js" value-ref="messageSourceController"/> </map> </property> <property name="order" value="1"/></bean>

MessageSource with RequireJS

• Usagedefine([ 'tmpl!example/templates/list', 'i18n!nls/messages'], function (listTemplate, messages) { alert(messages['createExample_loading']); };

<!– This will result in loading the following which can then be used in the page. --><script type="text/javascript" charset="utf-8" async="" data-requirecontext="_" data- requiremodule="nls/messages" src="js/nls/messages.js">

define({"root": { "createExample_loading":"Carga…", "createExample_form_label_data":"Datos:", "createExample_form_label_name":"Nombre:", "createExample_form_message_success":"Ejemplo \"<%= name %>\" se ha …" "createExample_form_button_save":"Cree Ejemplo“ } });

</script>

DEMO

Some I18n Best Practices

• Externalize ALL translatable text• Do not concatenate translations• Create duplicate / separate resources• Avoid text in images

• Introduce pseudo-translation tool

Externalize ALL Text• Example – Name:

– Notice that we have concatenated the : with the translated name label• "Name:" including the colon should be externalized

– Concatenation itself is a best practice violation– : and associated formatting can be different– It might also be in a different order

#messages.propertiesname.label=Name

#JSP page${messages['name.label']}: <input type="text" />

#messages.propertiesname.label=Name:

#JSP page${messages['name.label']} <input type="text" />

Do NOT Concatenate Translations

• For example:

• Attempted usage:

#messages.properties

key1=Someone namedkey2=likes hiking.

#JSP Page

${messages['key1']} Billy ${messages['key2']}

More Correct Way

• Create a single string with replaceable parameters

• Sentence maintains context – Parameters can be moved around to accommodate

language grammar• For example:

• And then it will be used as follows:key=Someone named {0} likes hiking.

<spring:message code="key" arguments="${hikersName}" text="Default text."/>

Create Separate Resources

• Counter-intuitive to code reuse concept• Same English strings should not be shared

• Within the same application, or even the same page• Create a separate key value pair for each occurrence

• Words change based on context• Concept of masculine and/or feminine, age classes, … • Or usage

• Similar English words may not be similar in another language

DEMO

Avoid Placing Text in Images

• An image that contains text will require a new image for each language

• It will also require a custom way to load the image• Impose the text over the image, using .css or other ingenious

alternative– Then the text can be stored in the resource bundles with all other

strings– And it won’t require a new image for each language

DEMO

I18n Testing (Dynamic Pseudo Translation)

• Configured to translate for specified locales• Simplifies testing

– Expansion– Special characters– Completeness– zz locale

• http://code.lds.org/maven-sites/stack/module.html?module=web-spring/#Pseudo_Translation_Message_Source_Facade

Dynamic Pseudo Translation

• The trick (delegate)<!-- Application Message Bundle --><bean id="messageSource" class="org.lds.stack.web.spring.i18n.message.PseudoMessageSourceFacade"> <constructor-arg ref="delegatingMessageSource" /></bean>

<bean id="delegatingMessageSource"    class="org.springframework.context.support.ReloadableResourceBundleMessageSource">    <property name="basename"> <list> <value>classpath:messages</value> </list> </property>    <property name="defaultEncoding" value="UTF-8"/></bean>

Example

DEMO

Credit where credit is due

• http://wiki.answers.com/Q/5_words_that_have_multiple_meanings

• http://en.wikipedia.org/wiki/Homonym

Lab 1: Internationalize a page

https://tech.lds.org/wiki/Internationalization_and_the_Java_Stack_-

_Part_2#Lab_1_Pseudo_Translator