(Vue.js 3 Options API) How do I access a child method?-CodePudding

I need to access a child component's method using Vue.js 3 with Options API. There is an answer at How to access to a child method from the parent in vue.js, but it is for Vue.js 2 and Vue.js 3 but with Composition API.

I still tried this, all in the parent component:

<dropdown-list @update="updateChildComponents"></dropdown-list>
<child-component-1 ref="childComponent1Ref" :url="url"></child-component-1>
<child-component-2 ref="childComponent2Ref" :url="url"></child-component-2>

and

methods: {
  updateChildComponents() {
    this.$refs.childComponent1Ref.childComponentMethod();
    this.$refs.childComponent2Ref.childComponentMethod();
  }
}

This actually successfully accesses the method, but I think this may not be the right way.

Secondly, I use a prop in the child component that I update in the parent and use in the child component's method, which updates only after the second event. I think these two may be related.

Child component:

props: ['url'],
methods: {
  childComponentMethod() {
    console.log(this.url); // can access the value from the previous event 
  }
}

I appreciate any help.

CodePudding user response：

For communication between the parent and the children you should trasfer the value with props. In case the value is changing in the parent you must add watch. It called 1 way binding because the parent cant see the changes in the child component.

Parent -> child = use props.

Child -> parent = use emits and on event.

<script>
import { reactive,watch, computed,onMounted } from "vue";


export default {
  components: { 
  },
  props: { metadata: String },
  emits: [""],
  setup(props) {
    onMounted(async () => {
    //first initilize 
      if (props.metadata) {
        state.metadataName = props.metadata;
      }
    });
    //track after the changes in the parent
    watch(
      () => props.metadata,
      async (metadata) => {
        if (metadata) {
          
        }
      }
    );
    return {
     
    };
  },
};
</script>