Portal Showcase
f:converter
The f:converter Facelet tag exposes the functionality of a Converter inside Facelet views.f:converter
tags facilitate conversion of complex data structures into UI data and back.
General Usage
Converters must be annotated with @FacesConverter (or declared as a converter in afaces-config.xml
file) and implement Converter in order to be accessible via the f:converter
tag.
Source Code
<ui:composition xmlns="http://www.w3.org/1999/xhtml" xmlns:f="http://xmlns.jcp.org/jsf/core" xmlns:ui="http://xmlns.jcp.org/jsf/facelets" xmlns:h="http://xmlns.jcp.org/jsf/html"> <h:form> <h:selectOneMenu id="selectOneMenuId" value="#{converterModelBean.country}"> <f:selectItems value="#{countryService.allCountries}" var="country" itemValue="#{country}" itemLabel="#{country.countryName}" /> <f:converter converterId="com.liferay.faces.showcase.converter.CountryConverter" /> </h:selectOneMenu> <hr /> <h:commandButton value="#{i18n['submit']}"> <f:ajax render="@form" execute="@form"/> </h:commandButton> <h:outputText value="#{i18n['selected-country-id']}:#{converterModelBean.country.countryId}, #{i18n['selected-country-name']}:#{converterModelBean.country.countryName}" /> </h:form> </ui:composition>
@ManagedBean @RequestScoped public class ConverterModelBean { @ManagedProperty(value = "#{countryService}") private CountryService countryService; // Private properties private Country country; private double number = 3.141516; public Country getCountry() { return country; } public CountryService getCountryService() { return countryService; } public double getNumber() { return number; } @PostConstruct public void postConstruct() { this.country = countryService.getAllCountries().get(0); } public void setCountry(Country country) { this.country = country; } public void setCountryService(CountryService countryService) { this.countryService = countryService; } public void setNumber(double number) { this.number = number; } }
@FacesConverter(value = "com.liferay.faces.showcase.converter.CountryConverter") public class CountryConverter implements Converter { // Static field must be declared volatile in order for the double-check idiom to work (requires JRE 1.5+) private static volatile Map<Long, Country> countryMap; @Override public Object getAsObject(FacesContext facesContext, UIComponent uiComponent, String value) { Object countryObject = null; if ((value != null) && !"".equals(value)) { Long countryId = Long.parseLong(value); countryObject = getCountryMap(facesContext).get(countryId); } return countryObject; } @Override public String getAsString(FacesContext facesContext, UIComponent uiComponent, Object value) { String strValue = ""; if (value != null) { Country country = (Country) value; strValue = Long.toString(country.getCountryId()); } return strValue; } protected Map<Long, Country> getCountryMap(FacesContext facesContext) { Map<Long, Country> countryMap = CountryConverter.countryMap; // First check without locking (not yet thread-safe) if (countryMap == null) { synchronized (CountryConverter.class) { countryMap = CountryConverter.countryMap; // Second check with locking (thread-safe) if (countryMap == null) { ELResolver elResolver = facesContext.getApplication().getELResolver(); ELContext elContext = facesContext.getELContext(); CountryService countryService = (CountryService) elResolver.getValue(elContext, null, "countryService"); countryMap = CountryConverter.countryMap = countryService.getCountryMap(); } } } return countryMap; } }
Liferay Faces Bridge Implementation 5.0.0 + Liferay Faces Portal 5.0.0 + Showcase Common 3.1.1 + Liferay Faces Util 3.4.1 + Mojarra 2.2.20