Accessing a Parent Component's Methods from Child Component in Vue.js

In Vue.js, component-based architecture forms the basis of building powerful, interactive applications. Sometimes, there might be a requirement to access a parent component’s methods from a child component. Vue.js does provide a way to interact between parent and child components, and shared methods are a part of this interaction.

The correct way to access a parent component’s methods from a child component is indeed by using this.$parent.methodName(). This allows the child component to call a method defined in its parent component in Vue.js.

Let's dive a little deeper with an example:

// Parent Component
Vue.component('parent-component', {
  methods: {
    parentMethod() {
      console.log('Parent method called');
    }
  },
  template: '<child-component></child-component>'
});

// Child Component
Vue.component('child-component', {
  mounted() {
    this.$parent.parentMethod();
  },
  template: '<div>Child Component</div>'
});

new Vue({ el: '#app' });

In this example, parentMethod() is defined in the parent-component. If the child-component needs to call this method, it should use this.$parent.parentMethod(), as seen within its mounted() lifecycle hook.

Considerations and Best Practices

While accessing parent methods from child component can be handy, it is important to use it with caution. This is because it makes the child component strongly coupled with the parent component, damaging the reusability of the child component.

It is therefore often recommended to use other forms of component interaction, like props for downlink communication (parent to child) and events for uplink communication (child to parent). Another best practice is using a centralized state management like Vuex to maintain shared data and functions.

In spectacle cases where the interaction between components is complex involving several layers of components, using this.$parent.methodName() can immediately become tricky to manage and debug.

Remember, applying the best way to interact between parent and child components varies according to the specific use case and requirements at hand. Accessibility, loose coupling and code readability should always be the top priority.