Book Image

Real-World Svelte

By : Tan Li Hau
4.3 (4)
Book Image

Real-World Svelte

4.3 (4)
By: Tan Li Hau

Overview of this book

Svelte has quickly become a popular choice among developers seeking to build fast, responsive, and efficient web applications that are high-performing, scalable, and visually stunning. This book goes beyond the basics to help you thoroughly explore the core concepts that make Svelte stand out among other frameworks. You’ll begin by gaining a clear understanding of lifecycle functions, reusable hooks, and various styling options such as Tailwind CSS and CSS variables. Next, you’ll find out how to effectively manage the state, props, and bindings and explore component patterns for better organization. You’ll also discover how to create patterns using actions, demonstrate custom events, integrate vanilla JS UI libraries, and progressively enhance UI elements. As you advance, you’ll delve into state management with context and stores, implement custom stores, handle complex data, and manage states effectively, along with creating renderless components for specialized functionalities and learning animations with tweened and spring stores. The concluding chapters will help you focus on enhancing UI elements with transitions while covering accessibility considerations. By the end of this book, you’ll be equipped to unlock Svelte's full potential, build exceptional web applications, and deliver performant, responsive, and inclusive user experiences.
Table of Contents (22 chapters)
1
Part 1: Writing Svelte Components
6
Part 2: Actions
10
Part 3: Context and Stores
16
Part 4: Transitions

Defining the Svelte store

To understand why Svelte reactivity is limited within a Svelte component, we must first understand how Svelte’s reactivity works.

Unlike some other frameworks, Svelte reactivity works during build time. As Svelte compiles a Svelte component into JavaScript, Svelte looks at each variable and tracks the variable to see when the variable changes.

Instead of tracking all the variables throughout the application, Svelte limits itself to only analyzing and compiling one file at a time. This allows Svelte to compile multiple Svelte component files in parallel but also means that a Svelte component would not be aware of variable changes that happen in other files.

A common situation where a variable change is not tracked is when the variable is defined in a separate file and imported into the current component.

In the following code snippet, the quantity variable is imported from a separate file. Svelte will not track any changes to the quantity...