Refactoring Vue 3's Composition API: How to Manage Computed Properties Effectively

Learn how to refactor computed properties in Vue 3's Composition API for better project organization. Isolate persistent and unique state management with clear examples.
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Refactoring Vue 3's Composition API: How to Manage Computed Properties Effectively

The introduction of Vue 3's Composition API has made state management much more modular and flexible. However, many developers, especially those new to this paradigm, might find it challenging to organize computed properties and state management effectively. This guide addresses a common question: How can I refactor a computed property into a separate file?

The Problem: Isolating Computed Properties

When writing components using the Composition API, developers often create computed properties within the same component file. While this approach works fine for smaller projects, it can become unwieldy as applications grow. The question arises: Should I create a new component for computed properties, or can they be housed in a separate JavaScript file?

Let's take a look at a working example of a Vue component and explore how to refactor the computed property for better organization.

The Original Component

Here’s the initial version of the Vue component where the favoriteRecipes computed property is defined directly within the setup() function:

[[See Video to Reveal this Text or Code Snippet]]

Initial Thoughts on Refactoring

The immediate approach to refactoring is to split the component into two files:

Create a state.js file for the state and computed property.

Adjust the recipes.vue file to import these elements.

Refactoring Steps

1. Creating state.js

First, you will want to define your state and computed properties in a separate file to enhance modularity. Here’s what the state.js would look like:

[[See Video to Reveal this Text or Code Snippet]]

2. Updating recipes.vue

Next, you will update the recipes.vue component to utilize the newly defined state and computed property:

[[See Video to Reveal this Text or Code Snippet]]

Important Consideration: State Persistence

While the above solution is clean and straightforward, it introduces a notable consideration: State persistence. By exporting state and favoriteRecipes directly, any change made in one component will affect all other components using the same state. This is not always desirable, especially if you want unique states per component.

Creating Unique Component States

To ensure that each component has its unique state, you can refactor state.js to return a function. This way, every time you call it, it will provide a fresh instance of state:

[[See Video to Reveal this Text or Code Snippet]]

Final Update to recipes.vue

Now, the recipes.vue will look like this:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

Refactoring computed properties and state management in Vue 3 using the Composition API is not just about moving code around—it's about setting up a more scalable and manageable architecture for your application. By leveraging separate JavaScript files and considering state persistence, you can build components that are clean, effective, and easy to maintain.

With these refactorings, you’ll be able to have both persistent and unique states across your applications. Happy coding with Vue 3!