Polymer 1.0 Dom-Repeat Bind Array <p>In my try to update to Polymer 1.0 I got the following problem with Data-Binding:</p> <p>My Polymer 0.5 Webapp uses a Repeat-Template to generate Checkboxes for some Categories. All <code>checked</code> values are bound to an array (<code>sortedCatsArray</code>) with the category-ids as key. Here is my first attempt to update that part to Polymer 1.0, but it doesn't work...</p> <pre><code> &lt;template is="dom-repeat" items="{{sortedCatsArray}}" as="category"&gt; &lt;paper-checkbox for category$="{{category.id}}" checked="{{filterChkboxes[category.id]}}"&gt;&lt;/paper-checkbox&gt; &lt;/template&gt; </code></pre> <p>As you may read in the <a href="https://www.polymer-project.org/1.0/docs/devguide/data-binding.html#path-binding" rel="nofollow">docs</a>, it is no longer possible to bind to Array-Properties with square-brackets (now that way: <code>object.property</code>). May anybody tell me if it's still possible to bind all generated checkbox-values in one array? </p> <p><strong>Update #1</strong></p> <p>As you may read in the <a href="https://www.polymer-project.org/1.0/docs/devguide/data-binding.html#array-binding" rel="nofollow">docs</a>, Array-Binding by index is not supported. So I tried to use that example from the docs for my case and wrote the following code. If I run this code, it seems to work as expected: the first and third checkbox is checked. But I also want the array to be changed if I manual check/uncheck a checkbox. That does not happen, only if I change the array (in the <code>ready</code>-function) the checkbox gets checked...</p> <pre><code>&lt;dom-module id="my-index"&gt; &lt;link rel="import" type="css" href="/css/index.css"&gt; &lt;template&gt; &lt;template is="dom-repeat" items="{{sortedCatsArray}}" as="category"&gt; &lt;paper-checkbox for category$="{{category.id}}" checked="{{arrayItem(filterChkboxes.*,category.id)}}" on-change="test"&gt;&lt;/paper-checkbox&gt; &lt;/template&gt; &lt;/template&gt; &lt;/dom-module&gt; &lt;script&gt; Polymer({ is: "my-index", properties: { filterChkboxes: { type: Array, notify: true, observer: "filterChkboxesChanged", value: function(){return[true,false,true,false];} }, sortedCatsArray: { type: Array, value: function(){return[{id: 0}, {id: 1},{id: 2},{id: 3}]}, notify: true }, }, ready: function(){ this.set('filterChkboxes.1',true); }, test: function(){ console.log(this.filterChkboxes); }, observers: [ 'filterChkboxesChanged(filterChkboxes.*)' ], arrayItem: function(array, key){ return this.get(key, array.base); }, filterChkboxesChanged: function(changes){ console.log(changes); }, }); &lt;/script&gt; </code></pre>