1. Introduction

In this tutorial, we will learn how to work with actions and asynchronous (async) data in Vuex. Vuex is a state management pattern + library for Vue.js applications. It serves as a centralized store for all the components in an application.

Goals

• Understand how to handle actions in Vuex
• Learn how to manage async operations
• Get a grip on committing mutations in Vuex

Learning Outcomes

• You'll be able to use Vuex actions to dispatch mutations
• You'll learn how to handle async operations in Vuex
• You'll understand the best practices for committing mutations

Prerequisites

• Basic knowledge of Vue.js
• Familiarity with JavaScript ES6 syntax
• Understanding of asynchronous programming in JavaScript

2. Step-by-Step Guide

Actions in Vuex are similar to mutations, but there are two main differences:
- Actions commit mutations.
- Actions can contain arbitrary asynchronous operations.

Let's look at an example of an action:

actions: {
  incrementAsync ({ commit }) {
    setTimeout(() => {
      commit('increment')
    }, 1000)
  }
}

In this example, we use the setTimeout JavaScript function to simulate an async operation. After one second, our action commits the increment mutation.

3. Code Examples

Example 1: Simple Action

// Defining the Vuex store
const store = new Vuex.Store({
  state: {
    count: 0
  },
  mutations: {
    increment (state) {
      state.count++
    }
  },
  actions: {
    increment ({ commit }) {
      commit('increment')
    }
  }
})

// Dispatching the action
store.dispatch('increment')

In this example, we define a Vuex store with a simple state: count. We then define a mutation increment which increases the count by 1, and an action increment which commits the increment mutation. Finally, we dispatch the increment action, which results in the count being increased by 1.

Example 2: Async Action

// Defining the Vuex store
const store = new Vuex.Store({
  state: {
    count: 0
  },
  mutations: {
    increment (state) {
      state.count++
    }
  },
  actions: {
    incrementAsync ({ commit }) {
      setTimeout(() => {
        commit('increment')
      }, 1000)
    }
  }
})

// Dispatching the async action
store.dispatch('incrementAsync')

In this example, we define an async action incrementAsync. This action waits for 1 second before committing the increment mutation.

4. Summary

In this tutorial, we've learned how to handle actions and async operations in Vuex. We've learned how to commit mutations and dispatch actions.

For further learning, you can look into Vuex modules, which allow for more complex state management. You can also explore how to use Vuex with Vue Router for route-level state management.

5. Practice Exercises

1. Exercise 1: Create a Vuex store with a state that contains a list of todos. Each todo should have a title and a completed property. Define a mutation addTodo that adds a new todo to the list, and an action addTodoAsync that commits the addTodo mutation after a delay of 1 second.

2. Exercise 2: Extend the Vuex store from exercise 1 by adding a mutation toggleTodo that toggles the completed property of a todo, and an action toggleTodoAsync that commits the toggleTodo mutation after a delay of 1 second.

3. Exercise 3: Further extend the Vuex store from exercise 2 by adding a getter completedTodos that returns all todos where completed is true.