Using Svelte Store in a Vite Project

1. Introduction

This tutorial aims to guide you through the process of using Svelte Store, a state management solution, within a Vite project. By the end of this tutorial, you'll be able to create, update, and react to changes in your application's state using Svelte Store.

You will learn:

• What Svelte Store is and how it works
• How to install and set up Svelte Store in a Vite project
• How to create, update, and subscribe to a Svelte Store

Prerequisites:

• Basic knowledge of JavaScript and Svelte
• Basic understanding of state management
• Installed Node.js and npm on your machine

2. Step-by-Step Guide

Setting up a new Vite project

First, we'll need to set up a new Vite project. Open your terminal and run the following command:

npx create-vite my-app --template svelte

This will create a new Vite project using the Svelte template.

Installing Svelte Store

Svelte Store is included in the Svelte package, so you don't need to install it separately. If you're using a different state management solution and want to switch to Svelte Store, you just need to import it from 'svelte/store' in your component files.

Creating a Svelte Store

To create a Svelte Store, import writable from 'svelte/store' and call it with an initial value:

import { writable } from 'svelte/store';

const count = writable(0); // Creates a store with an initial value of 0

Updating a Svelte Store

Updating the state of a Svelte Store is done by calling the update or set methods:

count.set(5); // Sets the state to 5

count.update(n => n + 1); // Increments the state by 1

Subscribing to a Svelte Store

You can subscribe to a Svelte Store using the subscribe method. This method takes a function that will be called whenever the state changes:

count.subscribe(value => {
  console.log(value); // Logs the current state
});

3. Code Examples

Example 1: Counter Component

<script>
  // Import the writable store
  import { writable } from 'svelte/store';

  // Create the count store with an initial value of 0
  const count = writable(0);
</script>

<button on:click={() => count.update(n => n + 1)}>
  Increment
</button>

<!-- Use the $ syntax to access the current value of the store -->
<p>{$count}</p>

In this example, we create a counter component. Each time the "Increment" button is clicked, the count store is incremented by 1, and the new value is displayed in the paragraph.

Example 2: Todo List Component

<script>
  import { writable } from 'svelte/store';

  const todos = writable([]);

  function addTodo(title) {
    todos.update(list => [...list, { title, done: false }]);
  }
</script>

<input bind:value={title} type="text">
<button on:click={() => addTodo(title)}>
  Add Todo
</button>

<ul>
  {$todos.map(todo => (
    <li>
      <input type="checkbox" bind:checked={todo.done}>
      {todo.title}
    </li>
  ))}
</ul>

In this example, we create a todo list component. The todos store is an array of todo objects. Each todo object has a title and a done property. The addTodo function adds a new todo to the list.

4. Summary

In this tutorial, you learned how to use Svelte Store in a Vite project. You learned how to create, update, and subscribe to a Svelte Store, and you saw examples of how to use a Svelte Store in a Svelte component.

Next, I recommend learning about derived stores and custom stores in Svelte Store. Derived stores allow you to create stores based on the state of other stores, and custom stores allow you to define your own methods for updating the state.

Here are some resources to help you continue learning:

• Svelte Store Documentation
• Vite Documentation

5. Practice Exercises

Exercise 1: Counter Component

Create a counter component with increment and decrement buttons. The state of the counter should be stored in a Svelte Store.

Exercise 2: Todo List Component

Create a todo list component with the ability to mark todos as done. The list of todos should be stored in a Svelte Store.

Exercise 3: Weather Component

Create a weather component that displays the current temperature. The temperature should be stored in a Svelte Store and updated every second.

Remember to practice regularly and apply what you've learned in your own projects. Happy coding!