How to display all enum values as with enum pr

问题:

I have a RoleStatus enum which is as being a property of Role entity mapped to an integer in the DB (but that part is irrelevant). I'd like to present a List<Role> in a <p:dataTable> in which one column should have a <h:selectOneMenu> for the RoleStatus property of the Role entity. How can I implement this with or without OmniFaces?

Here's the enum:

public enum RoleStatus {

    ACTIVE(1, "Active"),
    DISABLE(2, "Disable");

    private final int intStatus;
    private final String status;

    private RoleStatus(int intStatus, String status) {
        this.intStatus = intStatus;
        this.status = status;
    }

    public int getIntStatus() {
        return status;
    }

    public String getStatus() {
        return status;
    }

}

Here's the backing bean:

@ManagedBean
@ViewScoped
public class RoleController {

    private List<Role> roles;

    @ManagedProperty("#{roleService}")
    private IRoleService roleService;

    @PostConstruct
    public void init() {
        roles = roleService.getRoles();
    }

    public List<Role> getRoles() {
        return roles;
    }

}

Finally, the data table where I'd like to have a <h:selectOneMenu> for the RoleStatus property of Role entity, showing all available enum values as select item options.

<h:form id="roleForm">
    <p:dataTable value="#{roleController.roles}" var="role">
        <p:column>
            <h:outputText value="#{role.roleid}" />
        </p:column>
        <p:column>
            <h:inputText value="#{role.role}" />
        </p:column>
        <p:column>
            <h:inputText value="#{role.description}" />
        </p:column>
        <p:column>
            <h:selectOneMenu value="#{role.roleStatus}">
                <!-- How??? -->
            </h:selectOneMenu>
        </p:column>
    </p:dataTable>
</h:form>

How can I achieve this? Do I need the OmniFaces SelectItemsConverter?

回答1:

You don't need a converter. JSF has already a builtin enum converter.

Without OmniFaces, here's how you could provide the enum values as available items of <h:selectOneMenu>:

1. Add this method to RoleController:

   public RoleStatus[] getRoleStatuses() {
       return RoleStatus.values();
   }
   

   This way, all enum values are available by #{roleController.roleStatuses}.

2. Then use this dropdown:

   <h:selectOneMenu value="#{role.roleStatus}">
       <f:selectItems value="#{roleController.roleStatuses}" var="roleStatus"
           itemValue="#{roleStatus}" itemLabel="#{roleStatus.status}" />
   </h:selectOneMenu>
   

   Note: as those values are static/applicationwide, it doesn't hurt to move the method to a separate @ApplicationScoped bean.

   ---

With OmniFaces, you could remove the additional getter and just import the enum directly via <o:importConstants>:

1. Add this somewhere in top of your template (assuming that it's in com.example package):

   <o:importConstants type="com.example.RoleStatus" />
   

   This way, the enum class itself is available by #{RoleStatus} (note the capitalization!).

2. Then use this dropdown:

   <h:selectOneMenu value="#{role.roleStatus}">
       <f:selectItems value="#{RoleStatus.values()}" var="roleStatus"
           itemValue="#{roleStatus}" itemLabel="#{roleStatus.status}" />
   </h:selectOneMenu>