Repeating a template from "content" does not work with repeat="d in data"

[FunkMonkey]

I am trying to repeat a template that is in the content of a polymer element within the shadow dom, just like it is achieved in polymer-list.

This works for repeat="{{data}}", but not for repeat="{{ d in data }}.

Here is a shortened version of polymer-list, that shows the problem:

<polymer-element name="x-repeat">
    <template>
        <div>
            <shadow></shadow>
        </div>
    </template>
    <script>Polymer('x-repeat', {
        data: ["foo", "bar"],
        enteredView: function() {
            this.template = this.querySelector('template');
          },

         templateChanged: function() {
            this.template.setAttribute('repeat', '{{ data }}'); // works
            // this.template.setAttribute('repeat', '{{ d in data }}'); // does not work
            this.template.model = this;
        }
    });</script>
</polymer-element>

And used like this:

<x-repeat>
    <template>
        <div>Data</div>
    </template>
</x-repeat>

repeat="{{data}}" will correctly create two divs, whereas switching the code to repeat="{{ d in data }} creates none.

Is this a bug or expected behaviour?

[dfreedm]

The "in" syntax is provided by the polymer-expressions library, and requires you to set "bindingDelegate" on the template to use that syntax.

this.template.bindingDelegate = new PolymerExpressions();
this.template.setAttribute('repeat', '{{ d in data }}');

Here is a working JSBin version: http://jsbin.com/UVIJoha/1/edit

[FunkMonkey]

thank you! works like a charm! :)