title: How to prevent props from reseting when child component updates?
body: <p><code>avatarid</code> and <code>relationlist</code> are passed from parent, when an image is uploaded, avatarid changed, but avatarid will be reseted to original if relationlist is changed (add or remove item from RelationTable component).</p>
  <p>I think it is that the<code>RelationTable</code> rerendering causes the parent to reload. How can I stop such reseting when child component updates. Thanks.</p>
  <pre><code>&lt;template&gt;
  
      &lt;el-upload
        class=&quot;avatar-uploader&quot;
        action
        :http-request=&quot;uploadAvatar&quot;
        accept=&quot;image/jpeg,image/jpg,image/png&quot;
        :after-upload=&quot;uploadAvatarSucc&quot;
      &gt;
      &lt;RelationTable ref=&quot;relationTable&quot; :relationlist=&quot;relationlist&quot; @delete=&quot;removeRelation&quot; /&gt;
  
  &lt;/template&gt;
  
  export default {
    name: 'relation-component',
    props: {
      avatarid: {
        type: String,
        default: ''
      },
      relationlist: {
        type: Array,
        default: null
      }
    },
    methods: {
      uploadAvatarSucc(res) {
        this.avatarid = res.imageId
      },
      removeRelation(index) {
        if (this.relationlist.length &gt; 0) {
          this.relationlist.splice(index, 1)
        }
      }
    }
  }
  </code></pre>