Communicating between Components with Vue.js and 'v-bind'

In Vue.js framework, data is communicated down the component hierarchy through props. The built-in directive v-bind is the recommended and essential tool for this task. 'v-bind' is used to bind data to a child component's attributes, which can then be accessed as props within the child component.

Here's how you can use v-bind:

// Parent Component
<template>
  <div>
    <child-component v-bind:parentData="message"></child-component>
  </div>
</template>

<script>
import ChildComponent from './ChildComponent.vue';

export default {
  components: {
    ChildComponent
  },
  data() {
    return {
      message: 'Hello from parent!'
    }
  }
}
</script>

// Child Component
<template>
  <div>
    <p>{{ parentData }}</p>
  </div>
</template>

<script>
export default {
  props: ['parentData']
}
</script>

In the above example, the v-bind directive is used in the parent component to bind the message data to the attribute parentData of the child component. The child component receives this data as a prop and can access its value.

Directly setting properties on the child component instance or modifying the child component's 'data' object are considered bad practices. It breaks the one-way data flow since Vue.js promotes component communication where parent components pass data to child components via props, and child components emit events to communicate with parent components. These practices can also lead to unexpected behavior due to the reactivity system of Vue.js.

Using a global event bus to pass data between components could be an overkill and leads to code that is difficult to trace and understand. Props and events are perfectly sufficient for most cases, while more complex state management can be handled with Vuex - Vue.js's own state management library.

In conclusion, understanding and correctly using 'v-bind' to pass data to child components can lead to more readable, maintainable, and bug-free code in Vue.js.