Using iron-ajax to grab string and insert onto page - ajax

Question

<template is="dom-bind">
<iron-ajax
auto
url="http://localhost:9000/api/version"
last-response="{{versionNumber}}"
verbose
></iron-ajax>
<template is="dom-repeat" items="{{versionNumber}}">
<small class="u-ml+">{{item.first}}</small>
</template>
<template>
<small>[[versionNumber]]</small>
</template>
</template>
I'm a little bit lost with Polymer - I have an iron-ajax element which is set up to talk an API endpoint, which is returning the current version of my application.
I want to be able to bind this version number directly on the page. Is there something I'm doing incorrectly in the above code?
I tried using a dom-repeat template and attempting to grab the first item, but I don't seem to be getting anything. Same with attempting to one-way bind inside of a <small> tag.
My understanding is that if I'm within a dom-bind template, I don't have to define a custom element.

Answer 1

Yes, data-binding works inside of a dom-bind template without the need for a custom element.
One problem in your code is the template tag around <small>
<template>
<small>[[versionNumber]]</small>
</template>
The content of a template by itself won't be shown/rendered in the DOM. See http://www.html5rocks.com/en/tutorials/webcomponents/template/ for some detailed information about templates).
Using <small>[[versionNumber]]</small> inside of your dom-bind template with the extra template tag should work.
Another issue is, that iron-ajax by default handles responses as JSON, so will probably run into a parse error when it receives a string and last-response will get no value.
You would have to specify the handleAs property of iron-ajax accordingly.
<iron-ajax handle-as="text" ...>
And dom-repeat will only work for arrays.