chart-property-behavior.html

<script>
  var ChartBehaviors = ChartBehaviors || {};
  /** @polymerBehavior */
  ChartBehaviors.ChartPropertyBehavior = Polymer.dedupingMixin(function(superClass) {
    return class extends superClass {
      static get properties() {
        return {
          type: {
            type: String,
            readOnly: true,
            value: 'bar',
          },

          chart: {
            notify: true
          },

          data: {
            type: Object,
            value: function () {
              return {};
            }
          },

          options: {
            type: Object,
            value: function () {
              return {};
            }
          }
        };
      }

      static get observers() {
        return [
          '_configurationChanged(data.*, options.*)'
        ];
      }

      _configurationChanged(dataRecord, optionsRecord) {
        if (dataRecord.base.labels && dataRecord.base.datasets) {
          this.hasData = true;
        } else {
          this.hasData = false;
        }

        if (this.hasData && this.isAttached) {
          this._queue();
        }
      }
    }
  });

</script>