Always wanted to check out @sveltejs (aka. "the next big thing in web dev") but never got time for it? ⏰
🔥 I've got a 10-tweet crash course for you! 👇
(Spoiler alert: Svelte is so intuitive and easy to use that you may feel like you already know it! 🥳)
#javascript #svelte
🔥 I've got a 10-tweet crash course for you! 👇
(Spoiler alert: Svelte is so intuitive and easy to use that you may feel like you already know it! 🥳)
#javascript #svelte
1/10
How Svelte works:
- Compiler: Doesn't ship a Svelte "library" to users, but build-time optimized plain JS
- Components: App is made up of composable UI elements
- Reactive: Event/User interaction triggers chain of state changes, autoupdating components throughout entire app
How Svelte works:
- Compiler: Doesn't ship a Svelte "library" to users, but build-time optimized plain JS
- Components: App is made up of composable UI elements
- Reactive: Event/User interaction triggers chain of state changes, autoupdating components throughout entire app
2/10
UI is a component tree. A component defines how your app should interpret some abstract "state" values, so that it can turn them into DOM elements in your browser, and ultimately pixels on your screen.
UI is a component tree. A component defines how your app should interpret some abstract "state" values, so that it can turn them into DOM elements in your browser, and ultimately pixels on your screen.
3/10
Each .svelte file contains a single component, consisting of 3 parts:
- <script> is component logic in JS
- <style> is CSS styling, scoped and applied to only the current component
- Svelte template, based on HTML but can use custom components and inline logic (like JSX)
Each .svelte file contains a single component, consisting of 3 parts:
- <script> is component logic in JS
- <style> is CSS styling, scoped and applied to only the current component
- Svelte template, based on HTML but can use custom components and inline logic (like JSX)
4/10
The Svelte template allows us to use our own custom components in addition to HTML elements. The `.svelte` file extension is optional if there's no ambiguity, but the first letter of a custom component MUST be in uppercase.
We can use JS expressions inside curly braces { }.
The Svelte template allows us to use our own custom components in addition to HTML elements. The `.svelte` file extension is optional if there's no ambiguity, but the first letter of a custom component MUST be in uppercase.
We can use JS expressions inside curly braces { }.
5/10
A common way to "control" how a child component behaves is to pass data into it as props (properties).
To accept a prop, expose a variable with `export`. It's important to use `let` because `const` is not reassignable.
Setting a prop is just like doing normal HTML.
A common way to "control" how a child component behaves is to pass data into it as props (properties).
To accept a prop, expose a variable with `export`. It's important to use `let` because `const` is not reassignable.
Setting a prop is just like doing normal HTML.
6/10
User actions trigger events. `on:` lets us listen to events and fire functions to update states. State changes will auto-update the UI.
Data generally flows from a parent to a child, but we can use `bind:` to simplify the state-update logic by allowing two-way data flow.
User actions trigger events. `on:` lets us listen to events and fire functions to update states. State changes will auto-update the UI.
Data generally flows from a parent to a child, but we can use `bind:` to simplify the state-update logic by allowing two-way data flow.
7/10
"Reactive statements" are those marked by `$:`
Svelte analyzes which variables they depend on. When any of those dependencies changes, the corresponding reactive statements will be rerun. Very useful for declaring derived states, or triggering "side effects".
"Reactive statements" are those marked by `$:`
Svelte analyzes which variables they depend on. When any of those dependencies changes, the corresponding reactive statements will be rerun. Very useful for declaring derived states, or triggering "side effects".
8/10
A reactive "store" makes it easy to share states across many components. It can exist in a separate JS file. To create a store, just wrap `writable` around a value.
In a component, we prefix store names with a `$` in order to directly use or update them. Compiler magic!
A reactive "store" makes it easy to share states across many components. It can exist in a separate JS file. To create a store, just wrap `writable` around a value.
In a component, we prefix store names with a `$` in order to directly use or update them. Compiler magic!
10/10
It's super easy to do asynchronous stuff like API requests with Svelte.
We can simply {#await} a Promise to resolve, displaying a "loading" placeholder before the result is ready.
Note that we await the Promise in the template section, so no `await` keyword in <script>.
It's super easy to do asynchronous stuff like API requests with Svelte.
We can simply {#await} a Promise to resolve, displaying a "loading" placeholder before the result is ready.
Note that we await the Promise in the template section, so no `await` keyword in <script>.
BONUS/10
Svelte comes with neat animated transitions built-in. Try giving your components a `transition:fly` property! There're also other types like fade, slide etc. You can use also `in:` `out:` to separately define intro/outros.
Attached to the transition prop are the params.
Svelte comes with neat animated transitions built-in. Try giving your components a `transition:fly` property! There're also other types like fade, slide etc. You can use also `in:` `out:` to separately define intro/outros.
Attached to the transition prop are the params.
👆 That's it - everything you need to get started with @sveltejs. 😁
Have fun! 🥳
(Thread crash course format inspired by @chrisachard 😁)
Have fun! 🥳
(Thread crash course format inspired by @chrisachard 😁)
I made a mistake here 🙈 It should be `bind:value` instead of `bind:input`. Sorry! 🙈🙈
Corrected pic 👇
Corrected pic 👇
