can.stache and lists {{#data.items}}

[justinbmeyer]

If data in {{#data.items}} changes from {} to {items: new can.List()} and then items are inserted in the can.List, live binding does not work.

This is due to the function created by makeEvaluator being only singly bound with:

can.compute(evaluator, null, false, true)

This is a performance improvement. In most cases, just the single value retrieved by the evaluator function is enough to be responding to. However, in this case, we need to not only bind to the evaluator data, but also the "length" property of the list value returned by evaluator.