vue实现从外部修改组件内部的变量的值

Vue.component('option-item-template', {
  props: ['item', 'optionitems', 'answer','hassub'],
  data: function () {
    return {
      classname: {
        "choose-content": true,
        "stan-answer": false
      }
    }
  },
  watch: {
    hassub: function (newValue, oldValue) {//当hassub属性的值发生改变时会执行下面的代码
      this.changeStanAnswer(newValue, this.answer);
    }
  },
  mounted: function () {//模块编译/挂载之后执行
    this.changeStanAnswer(this.hassub,this.answer);
  },
  methods: {
    changeStanAnswer: function (sub, answer) {
      if (sub && (answer.indexOf(this.optionitems.chooseName) != -1)) {
        this.classname = {
          "choose-content": true,
          "stan-answer": true
        };
      } else {
        this.classname = {
          "choose-content": true,
          "stan-answer": false
        };
      }
    }
  },
  template: '<li class="mui-table-view-cell" v-if="optionitems.selectName || optionitems.selectImage">'
    + '<label :class="classname">'
    + '<input v-if= "item.data.itemType==2" type="checkbox" :name="item.data.tiKuId" v-bind:data-number="item.data.shiJuanNumber" data-type="checkbox" :value="optionitems.chooseName" />'
    + '<input v-else type="radio" :name="item.data.tiKuId" v-bind:data-number="item.data.shiJuanNumber" :value="optionitems.chooseName" data-type="radio" />'
    + '<span class= "choose-btn" >{{optionitems.chooseName}}</span>'
    + '<span class="choose-text">'
    + '{{optionitems.selectName}}'
    + '![在这里插入图片描述]()'
    + '</span>'
    + '</label></li>'
});