State machines with composables in Vue - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a state machine in the context of Vue composables?

A state machine is a way to manage different states and transitions between them in a predictable way, often implemented inside Vue composables to organize component logic clearly.

beginner

Why use composables for state machines in Vue?

Composables let you reuse state machine logic across components, keep code clean, and separate state management from UI, making apps easier to maintain.

intermediate

What Vue Composition API functions are commonly used in state machines?

Functions like ref to hold state, computed for derived states, and watch to react to state changes are commonly used in state machines.

intermediate

How do transitions work in a state machine composable?

Transitions are functions that change the current state to a new state based on rules, ensuring the app moves only between allowed states.

beginner

Give an example of a simple state machine with composables in Vue.

A simple toggle state machine can have states 'on' and 'off' with a transition function to switch between them, implemented using ref and a toggle method inside a composable.

What Vue function is best to hold the current state in a state machine composable?

A ref

B computed

C watch

D provide

ref holds reactive state values, perfect for the current state in a state machine.

What is the main purpose of transitions in a state machine?

A To change states following rules

B To render UI elements

C To fetch data from server

D To style components

Transitions control how the state changes, ensuring valid moves between states.

Which Vue Composition API function helps react to state changes in a state machine?

A computed

B ref

C watch

D inject

watch runs code when reactive data changes, useful for side effects on state changes.

Why is using composables for state machines better than putting logic directly in components?

A It makes components slower

B It allows reuse and cleaner code

C It hides the UI

D It disables reactivity

Composables help keep logic reusable and components focused on UI.

What would be a valid state transition in a toggle state machine?

A 'on' to 'loading'

B 'loading' to 'error'

C 'off' to 'error'

D 'on' to 'off'

A toggle machine usually switches only between 'on' and 'off' states.

Explain how you would build a simple toggle state machine using Vue composables.

Think about holding the current state and a function to change it.

Describe the benefits of managing component states with state machines inside composables.

Consider how state machines help organize logic and composables help share it.