title: How to bind an array of objects in Polymer 1.0?
body: <p>I have a menu who calls with iron-ajax the content of the page, this content is an html file who has the polymer element requested, this works fine. The problem I have is to change icons in the paper-toolbar depending of the content requested.
  It works fine in polymer 0.5, but in polymer 1.0 doesn't work.</p>
  
  <p>Here is my dom-repeat to put icons in dom</p>
  
  <pre><code>&lt;template is="dom-repeat" items="{{content.contextualButtons}}" as="button" id="repiteBotones"&gt;
     &lt;paper-icon-button contextual-action="{{button.action}}" icon="{{button.icon}}" on-tap="{{onContextualButtonTap}}"&gt;&lt;/paper-icon-button&gt;
  &lt;/template&gt;
  </code></pre>
  
  <p>This is my function to observer mutations, I didn't do this function, so I can't fully understand what this function does.</p>
  
  <pre><code>       attached: function () {
                     var self = this;
                     this.mo = new MutationObserver(function (mutations) {
                          mutations.forEach(function (m) {
                              for (i = 0; i &lt; m.removedNodes.length; i++) {
                                  self.content = null;
                              }
                              for (i = 0; i &lt; m.addedNodes.length; i++) {
                                  self.content = m.addedNodes[i];
                              }
                          });
                     }.bind(this));
                      this.mo.observe(this.$.content, { childList: true });
                  }
  </code></pre>
  
  <p>So, when I call some content, first time changes the contextual buttons, but other times nothing happened, I checked the array using </p>
  
  <pre><code>$0.contextualButtons
  </code></pre>
  
  <p>and the array changes as I expected, even I push extra objects into the array, but dom does not changes</p>
  
  <pre><code>$0.contextualButtons.push({ icon: 'social:person-addss', action: 'new' })
  </code></pre>
  
  <p>The declaration of my array is like this:</p>
  
  <pre><code>contextualButtons: {
                      type: Array,
                      value: function () { return []; },
                      observer: '_contextualButtonsChange'
                      //reflectToAttribute: true,
                      //notify: true
  
                  }
  </code></pre>
  
  <p>I tried to use observer, reflectToAttribute and notify but it not works, maybe I cant fully understand how it works.</p>
  
  <p>Anyone can help me? By the way, sorry for my english. Thaks!</p>