Using scoped models impacts 2-way property binding

[sorvell]

Given this type of usage:

<polymer-element name="x-thing">
  <template>
    <template repeat="{{user in users}}">
      <x-item manager="{{manager}}"></x-item>
    </template>
  </template>
  <script>
    Polymer('x-thing', {
      ready: function() {
        this.manager = {name: "Bob"};
      }
    });
  </script>
</polymer-element>

The expectation here is that x-thing's manager property is bound directly to x-item's manager property.

However, the use of the scoped model {{user in users}} makes the binding 1-way instead of 2-way. The model used to populate x-item is no longer x-thing but instead an object with a user property an x-thing as its prototype. Therefore, when x-item sets manager is does not change the value in x-thing.

This behavior can be worked around by setting a reference to the element inside itself like this:

<polymer-element name="x-thing">
  <template>
    <template repeat="{{user in users}}">
      <x-item manager="{{self.manager}}"></x-item>
    </template>
  </template>
  <script>
    Polymer('x-thing', {
      ready: function() {
        this.self = this;
        this.manager = {name: "Bob"};
      }
    });
  </script>
</polymer-element>

[sorvell]

This has been fixed.