God's Vue: An immersive tale (Chapter 2)
Tags: vue, webdev, javascript, learning
Published: 2024-07-14 16:56:31

**Chapter 2: Let There Be Light**

**The Birth of An Instance**

After laying down the foundation of Eden, the next step in the developer's journey was to bring light and structure to this nascent world.
 
With a clear vision in his mind, he placed his fingers on the cosmic keyboard and conjured the `createApp` function—an entity of mystical origin, responsible for the initiation of every Vue application in existence. To perform this task, the `createApp` function demanded the root component as an object, and in return, it created an application instance. This instance, now imbued with the essence of the developer’s vision, was destined to play a crucial role in the development ahead.

**Root and The Tree of Life**

To fully understand the gravity of the transaction that took place between the `createApp` function and the developer, we must grasp the significance of the root component and its role. 

The root component serves as the origin from which every other child component blooms, regardless of size, to play its part in developing the new world. It encapsulates the structure and behavior of the entire creation process. 

The developer was fully aware of the importance of this transaction and its outcome. It was the only way to give birth to a new instance and proceed with his plans. 

According to some divine sources, the following commandments were authored by the developer to perform the holy transaction:

```
import { createApp } from 'vue'
import App from './App.vue'

const app = createApp(App)
```

After the transaction, an instance was born, allowing the Vue application to be organized into a tree of nested and reusable components, initially branching from the root itself. This hierarchical structure allowed for a modular and scalable approach to the creation of the intended world. Each component serving a specific purpose, contributing to the overall harmony and functionality of the creation.

**Divine Configurations**

With the application instance in hand, the developer knew the greatness he could achieve and the glory that awaited Eden. This new world would soon be unleashed in its full splendor. The application instance was more than just a beginning; it was a divine tool imbued with the power to shape the very fabric of Eden. Among its many powers, the `.config` object stood out, allowing the developer to configure app-level options with precision and care.

The `.config` object was akin to a celestial scepter, giving the developer control over vital aspects of the application’s behavior. One such control was error handling, a safeguard to capture and manage errors from all descendant components:

```
app.config.errorHandler = (err, vm, info) => {
  // Handle the error gracefully
  console.error('Error captured: ', err)
}
```

It was crucial for the developer to apply these divine configurations before mounting the application, to define its behavior and environment. These configurations ensured that the application operated according to the developer’s divine intent, setting the stage for a harmonious and well-ordered process.

**App-Scoped Assets**

As the developer continued to wield the power of the application instance, he discovered even more remarkable capabilities that lay within his grasp. Among these were the methods for registering app-scoped assets. These assets, such as components, were essential elements that would be accessible throughout the entire realm of Eden, ensuring that the creation was both cohesive and versatile.

```
app.component('MyComponent', {
  template: '<div>A holy component</div>'
})
```

The application instance was not merely a static foundation; it was a living, breathing entity capable of growth and adaptation. By registering app-scoped assets, the developer could make sure Eden could reuse and access key elements from anywhere within its vast realm.

**Mounting the Creation**

After fully exploring the vast potential of the application instance, the time had come for the developer to finally bring light to his nascent world and begin its true development. However, despite all the power at hand, the application instance refused to render anything unless the `.mount()` method was called.

This method should be invoked after all app configurations and asset registrations. The return value of the `.mount()` method is the root component instance, unlike asset registration methods which return the application instance. The `.mount()` method also expected a container argument, symbolized by the ID `#app`. The container was a special vessel, an empty shell awaiting the essence of creation.

Hence, the developer provided it with the `#app` and invoked the sacred method:

```
app.mount('#app')
```

Suddenly, a burst of light exploded throughout Eden, and it finally started to breathe. The content of the app's root component was rendered inside this container element, which acted as a frame through which the masterpiece of Eden was revealed, showcasing the intricate structure and boundless possibilities of the developer's creation.

This act of mounting anchored the new world into the fabric of reality, setting the stage for the developer to begin what he was truly known for: the development of a great world.