How can I use @ManagedProperty in backing component?
This is partner selector composite component. The component checks the typed partner code in the database and fills the partner name if code is valid.
The component:
<cc:interface componentType="partnerSelComp">
<cc:attribute name="value" type="java.lang.Long"/>
</cc:interface>
<cc:implementation>
<span id="#{cc.clientId}" style="white-space:nowrap">
<p:inputText id="id" type="hidden" binding="#{cc.partnerId}"/>
<p:inputText id="code" binding="#{cc.code}">
<p:ajax event="blur" update="id code name" listener="#{cc.validate}" />
</p:inputText>
<p:inputText id ="name" disabled="true" binding="#{cc.name}" />
<p:message for="code"/>
</span>
</cc:implementation>
In encodeBegin() I got NPE because service is null:
@FacesComponent("partnerSelComp")
public class PartnerSelComp extends UIInput implements NamingContainer {
private InputText partnerId;
private InputText code;
private InputText name;
@ManagedProperty("#{partnerService}")
private PartnerService service;
@Override
public void encodeBegin(FacesContext context) throws IOException {
Partner p=null;
Long i = (Long) getValue();
if (i != null) {
p = findPartnerById(service.getList(), i);
}
fill( (i==null) , p); // fills the code and name fields
}
...
}
This is the bean I'd like to access. (later it will replaced with a JPA query.)
@ManagedBean(name = "partnerService")
@ApplicationScoped
public class PartnerService {
private List<Partner> list;
public PartnerService() {
list = new ArrayList<>();
list.add( new Partner(1, "A", "Partner A"));
list.add( new Partner(2, "B", "Partner B"));
list.add( new Partner(3, "C", "Partner C"));
list.add( new Partner(4, "D", "Partner D"));
list.add( new Partner(5, "E", "Partner E"));
list.add( new Partner(6, "E", "Partner F"));
}
public List<Partner> getList() {
return list;
}
public void setList(List<Partner> list) {
this.list = list;
}
}
The solution:
The use of the component:
<my:PartnerSelComp value="#{myBean.partnerId}" service="#{partnerService}"/>
The component xhtml:
<cc:interface componentType="partnerSelComp">
<cc:attribute name="value" type="java.lang.Long"/>
<cc:attribute name="service"/>
</cc:interface>
<cc:implementation>
<span id="#{cc.clientId}" style="white-space:nowrap">
<p:inputText id="id" type="hidden" binding="#{cc.partnerId}"/>
<p:inputText id="code" binding="#{cc.code}">
<p:ajax event="blur" update="id code name" listener="#{cc.validate}" />
</p:inputText>
<p:inputText id ="name" disabled="true" binding="#{cc.name}" />
<p:message for="code"/>
</span>
</cc:implementation>
I note, I tried it to pass the reference as attribute default value: <cc:attribute name="service" default="#{partnerService}"/> and <my:PartnerSelComp value="#{myBean.partnerId}"/> I don't know why but it didn't worked me, I had to set service attribute in my:PartnerSelComp as you see above.
And the backing component:
@FacesComponent("partnerSelComp")
public class PartnerSelComp extends UIInput implements NamingContainer {
private InputText partnerId;
private InputText code;
private InputText name;
@ManagedProperty("#{partnerService}")
private PartnerService service;
@Override
public void encodeBegin(FacesContext context) throws IOException {
Partner p=null;
Long i = (Long) getValue();
PartnerService service = getAttributeValue("service", null );
if (i != null) {
p = findPartnerById(service.getList(), i);
}
fill( (i==null) , p); // fills the code and name fields
}
@SuppressWarnings("unchecked")
private <T> T getAttributeValue(String key, T defaultValue) {
T value = (T) getAttributes().get(key);
return (value != null) ? value : defaultValue;
}
...
}
I have to use getAttributes().get(key) to get the reference and cast it to PartnerService.
Thanks for the answers.
