bower_components/polymer-element-catalog/app/elements/app-link/app-link.html

<script>
Polymer({
  is: 'app-link',
  extends: 'a',
  properties: {
    skipNav: Boolean
  },
  listeners: {
    'click': 'navigate'
  },
  navigate: function(e) {
    // allow for ctrl+click to open in new window
    if (e.ctrlKey || e.metaKey) {
      return true;
    } else {
      e.preventDefault();
      if (!this.skipNav) this.fire('nav', {url: this.href});
    }
  }
});
</script>