Sorting an array can result in an *Changed method firing

[sorvell]

If an element defines an array property foo and want to keep the array sorted, one might write code like this:

fooChanged: function() {
  this.foo.sort();
}

However, if the sort mutates the order of the array, the fooChanged method will be called again. This is because polymer reports array mutations as changes. This is appropriate for this use case. One probably wants to sort the array if it's new or if it mutates.

To fix this, we might consider adding a way to squelch changes.

[rafaelw]

This seems like an antipattern to me. If you mutate the data that you are observing in the callback which is called when it changes, you are going to have a bad time.

[sorvell]

Agree, I kept it open because it was related to arrays.

This type of thing calls for a computed property and now that we have computed properties I think we can just close this.