Custom refs with customRef in Vue - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a customRef in Vue?

A customRef lets you create a reactive reference with custom behavior for tracking and triggering updates. It gives you control over when Vue tracks dependencies and triggers reactivity.

beginner

How do you create a customRef in Vue?

You import <code>customRef</code> from Vue and call it with a factory function that returns <code>{ get, set }</code> methods to control tracking and triggering.

intermediate

Why would you use customRef instead of a normal ref?

Use customRef when you want to customize how and when Vue tracks dependencies or triggers updates, like debouncing input or throttling updates.

intermediate

What do the track and trigger functions do inside a customRef?

track tells Vue to watch this ref for changes, and trigger tells Vue to update any watchers when the ref changes.

intermediate

Give a simple example use case for customRef.

Debouncing a text input so Vue only updates the model after the user stops typing for a moment, reducing unnecessary updates.

What does customRef allow you to customize in Vue?

A How reactivity tracks and triggers updates

B The HTML template syntax

C The component lifecycle hooks

D The CSS styles of components

customRef customizes how Vue tracks dependencies and triggers reactive updates.

Which two methods must you provide inside the factory function passed to customRef?

A watch and unwatch

B render and update

C mount and unmount

D get and set

The factory function returns an object with get and set methods to control reactivity.

What is the purpose of the track function inside customRef?

A To stop Vue from tracking changes

B To tell Vue to watch this ref for changes

C To update the DOM immediately

D To reset the ref value

track registers the ref as reactive so Vue knows to watch it.

When might you want to use customRef?

A To debounce or throttle reactive updates

B To style components with CSS

C To define routes in Vue Router

D To create global Vuex stores

customRef is useful for controlling update timing like debouncing.

What happens if you don’t call trigger inside set in a customRef?

A The ref value won’t change

B Vue will throw an error

C Vue won’t update watchers when the value changes

D The component will unmount

Without calling trigger, Vue won’t notify watchers of changes.

Explain how customRef works in Vue and why you might use it.

Think about controlling when Vue notices changes.

Describe a simple example where customRef improves user experience in a Vue app.

Consider typing in a search box.