Firebase Element: Error if setting location declaratively from parent

[ebidel]

From @chriswalz on December 31, 2015 4:54

I have this code below in an element called

In another element I have this declaration.

I get this error: 'FIREBASE FATAL ERROR: Cannot parse Firebase url. Please use https://.firebaseio.com'

Copied from original issue: Polymer/polymer#3257

[ebidel]

From @chriswalz on December 31, 2015 5:3

My work clunky work around by creating a second property 'a'

<spark-input store="posts"></spark-input>
<firebase-collection location="https://removed.firebaseio.com/{{a}}" >
</firebase-collection>
   post: function() {
        this.a = this.store;
        // post code
  }