How to access static members in a Velocity template?
- by matt b
I'm not sure if there is a way to do this in Velocity or not:
I have a User POJO which a property named Status, which looks like an enum (but it is not, since I am stuck on Java 1.4), the definition looks something like this:
public class User {
// default status to User
private Status status = Status.USER;
public void setStatus(Status status) {
this.status = status;
}
public Status getStatus() {
return status;
}
And Status is a static inner class:
public static final class Status {
private String statusString;
private Status(String statusString) {
this.statusString = statusString;
}
public final static Status USER = new Status("user");
public final static Status ADMIN = new Status("admin");
public final static Status STATUS_X = new Status("blah");
//.equals() and .hashCode() implemented as well
}
With this pattern, a user status can easily be tested in a conditional such as
if(User.Status.ADMIN.equals(user.getStatus())) ...
... without having to reference any constants for the status ID, any magic numbers, etc.
However, I can't figure out how to test these conditionals in my Velocity template with VTL. I'd like to just print a simple string based upon the user's status, such as:
Welcome <b>${user.name}</b>!
<br/>
<br/>
#if($user.status == com.company.blah.User.Status.USER)
You are a regular user
#elseif($user.status == com.company.blah.User.Status.ADMIN)
You are an administrator
#etc...
#end
But this throws an Exception that looks like org.apache.velocity.exception.ParseErrorException: Encountered "User" at webpages/include/dashboard.inc[line 10, column 21] Was expecting one of: "[" ...
From the VTL User Guide, there is no mention of accessing a Java class/static member directly in VTL, it appears that the right hand side (RHS) of a conditional can only be a number literal, string literal, property reference, or method reference.
So is there any way that I can access static Java properties/references in a Velocity template? I'm aware that as a workaround, I could embed the status ID or some other identifier as a reference in my controller (this is a web MVC application using Velocity as the View technology), but I strongly do not want to embed any magic numbers or constants in the view layer.
