Logical Operators doesn't work anymore in 0.9

[drxcheng]

! || &&

Or is there an alternative way?

[arthurevans]

0.9 doesn't support any expressions, except for simple negation (!).

https://www.polymer-project.org/0.9/docs/migration.html#data-binding

In most cases, what you want is a computed binding:

<span>{{userType(user.type, defaultType)}}</span>

Where userType is a function like:

userType: function(type, default) {
 return type || default;
}

Note that in 0.9, computed bindings don't accept literal arguments at this point (that is, I can't use {{userType(user.type, "End User")}}. However I believe that's already checked in to master and should be in 1.0.