title: [dom-bind::_createEventHandler]: listener method not defined
body: <p>I am trying out polymer, but am having a problem in registering methods and calling them, I tried everything on the internet and nothing seems to work, I spent too many hours on this but with no results, please help me</p>
  
  <p>here is my code:</p>
  
  <pre><code>&lt;dom-module id="products-list"&gt;
  &lt;template&gt;
  &lt;template is="dom-bind"&gt;
     &lt;iron-ajax id="ajax" auto
         handle-as="json"
         last-response="{{ajaxResponse}}"&gt;&lt;/iron-ajax&gt;
     &lt;div class="main"&gt;
       &lt;template is="dom-repeat" items="[[ajaxResponse.dataResult]]"&gt;
         &lt;paper-card heading="[[item.name]]" image="[[item.image]]" class="pb16 w100 flex layout horizontal"&gt;
              &lt;div class="card-content"&gt;[[item.desc]]&lt;/div&gt;
              &lt;div class="card-actions"&gt;
                  &lt;paper-item&gt;
                      &lt;strong&gt;[[item.price]]&lt;/strong&gt;
                      &lt;div class="flex"&gt;&lt;/div&gt;
                      &lt;paper-button on-click="_addToCart" raised&gt;&lt;iron-icon icon="icons:add-shopping-cart"&gt;&lt;/iron-icon&gt;Add to cart&lt;/paper-button&gt;
                  &lt;/paper-item&gt;
              &lt;/div&gt;
         &lt;/paper-card&gt;
       &lt;/template&gt;
   &lt;/div&gt;
  &lt;/template&gt;
  &lt;/template&gt;
   &lt;script&gt;
      Polymer({
          is: "products-list",
          ready: function() {
              var baseUrl = getBaseURL();
              var token = getAccessToken();
              var namespace = getNamespace();
              var appKey = getAppKey();
              var appSecret = getAppSecret();
              var url = baseUrl + '/stream/product.json';
              var params = {
                  'page' : 0,
                  'size' : 25
              };
              var headers = {
                  'X-Auth-Token' : token,
                  'X-NAME-SPACE' : namespace,
                  'X-APP-KEY' : appKey,
                  'X-APP-SECRET' : appSecret,
              };
              var ajax = document.querySelector("#ajax");
              ajax.url = url;
              ajax.headers = headers;
          },
          properties: {
  
          },
          _addToCart: function (e) {
              console.log('You pressed button ' + e.model.item.name);
          }
      });
   &lt;/script&gt;
  </code></pre>
  
  <p>
    </p>
  
  <p>Everything works fine except for clicking the button, I am getting the following error:</p>
  
  <pre><code>[dom-bind::_createEventHandler]: listener method `_addToCart` not defined
  </code></pre>