message: vue
  -- implemented render
diff: import * as Vue from 'vue'
  import {Component, Prop} from 'vue-property-decorator'
  import {surveyCss} from "../defaultCss/cssstandard"
  - import {SurveyModel} from '../survey'
  + import {VueSurveyModel as SurveyModel} from './surveyModel'
  @Component
  export default class Survey extends Vue {
  @Prop
  survey: SurveyModel
  + forceUpdate() {
  + this.$forceUpdate();
  + }
  +
  constructor () {
  super();
  }
  +
  + mounted() {
  + this.survey.renderCallback = this.forceUpdate;
  + }
  + beforeDestroy() {
  + this.survey.renderCallback = undefined;
  + }
  +
  get hasTitle () {
  return !!this.survey.title && this.survey.showTitle;
  }
  