Reactivity
Declare state
Update state
Templating
Minimal template
Styling
import "./style.css";
export default function CssStyle() {
return (
<>
<h1 class="title">I am red</h1>
<button style={{ "font-size": "10rem" }}>I am a button</button>
</>
);
}
Loop
Event click
import { createSignal } from "solid-js";
export default function Counter() {
const [count, setCount] = createSignal(0);
function incrementCount() {
setCount(count() + 1);
}
return (
<>
<p>Counter: {count()}</p>
<button onClick={incrementCount}>+1</button>
</>
);
}
Dom ref
Conditional
import { createSignal, Switch, Match } from "solid-js";
const TRAFFIC_LIGHTS = ["red", "orange", "green"];
export default function TrafficLight() {
const [lightIndex, setLightIndex] = createSignal(0);
const light = () => TRAFFIC_LIGHTS[lightIndex()];
function nextLight() {
setLightIndex((lightIndex() + 1) % TRAFFIC_LIGHTS.length);
}
return (
<>
<button onClick={nextLight}>Next light</button>
<p>Light is: {light()}</p>
<p>
You must
<Switch>
<Match when={light() === "red"}>
<span>STOP</span>
</Match>
<Match when={light() === "orange"}>
<span>SLOW DOWN</span>
</Match>
<Match when={light() === "green"}>
<span>GO</span>
</Match>
</Switch>
</p>
</>
);
}
static const TRAFFIC_LIGHTS = ["red", "orange", "green"];
<let/lightIndex=0>
<const/light=TRAFFIC_LIGHTS[lightIndex]>
<button onClick() { lightIndex = (lightIndex + 1) % TRAFFIC_LIGHTS.length }>
Next light
</button>
<p>Light is: ${light}</p>
<p>
You must
<if=light === "red">STOP</if>
<else if=light === "orange">SLOW DOWN</else>
<else>GO</else>
</p>
Lifecycle
On mount
import { createSignal, onMount } from "solid-js";
export default function PageTitle() {
const [pageTitle, setPageTitle] = createSignal("");
onMount(() => {
setPageTitle(document.title);
});
return <p>Page title: {pageTitle()}</p>;
}
On unmount
import { createSignal, onCleanup } from "solid-js";
export default function Time() {
const [time, setTime] = createSignal(new Date().toLocaleTimeString());
const timer = setInterval(() => {
setTime(new Date().toLocaleTimeString());
}, 1000);
onCleanup(() => clearInterval(timer));
return <p>Current time: {time()}</p>;
}
Component composition
Props
Emit to parent
import { createSignal } from "solid-js";
import AnswerButton from "./AnswerButton.jsx";
export default function App() {
const [isHappy, setIsHappy] = createSignal(true);
function onAnswerNo() {
setIsHappy(false);
}
function onAnswerYes() {
setIsHappy(true);
}
return (
<>
<p>Are you happy?</p>
<AnswerButton onYes={onAnswerYes} onNo={onAnswerNo} />
<p style={{ "font-size": "50px" }}>{isHappy() ? "😀" : "😥"}</p>
</>
);
}
Slot
Slot fallback
Context
import { createSignal } from "solid-js";
import { UserContext } from "./UserContext";
import UserProfile from "./UserProfile";
export default function App() {
const [user, setUser] = createSignal({
id: 1,
username: "unicorn42",
email: "[email protected]",
});
function updateUsername(newUsername) {
setUser({ ...user(), username: newUsername });
}
return (
<>
<h1>Welcome back, {user().username}</h1>
<UserContext.Provider value={[user, updateUsername]}>
<UserProfile />
</UserContext.Provider>
</>
);
}
<let/user={
id: 1,
username: "unicorn42",
email: "[email protected]",
}>
<const/updateUsername(newUsername) {
user = { ...user, username: newUsername };
}>
<h1>Welcome back, ${user.username}</h1>
<context={ ...user, updateUsername }>
<UserProfile />
</context>
Form input
Input text
import { createSignal } from "solid-js";
export default function InputHello() {
const [text, setText] = createSignal("Hello world");
function handleChange(event) {
setText(event.target.value);
}
return (
<>
<p>{text()}</p>
<input value={text()} onInput={handleChange} />
</>
);
}
Checkbox
import { createSignal } from "solid-js";
export default function IsAvailable() {
const [isAvailable, setIsAvailable] = createSignal(false);
function handleChange() {
setIsAvailable((previousValue) => !previousValue);
}
return (
<>
<input
id="is-available"
type="checkbox"
checked={isAvailable()}
onChange={handleChange}
/>
<label for="is-available">Is available</label>
</>
);
}
Radio
import { createSignal } from "solid-js";
export default function PickPill() {
const [picked, setPicked] = createSignal("red");
function handleChange(event) {
setPicked(event.target.value);
}
return (
<>
<div>Picked: {picked()}</div>
<input
id="blue-pill"
checked={picked() === "blue"}
type="radio"
value="blue"
onChange={handleChange}
/>
<label for="blue-pill">Blue pill</label>
<input
id="red-pill"
checked={picked() === "red"}
type="radio"
value="red"
onChange={handleChange}
/>
<label for="red-pill">Red pill</label>
</>
);
}
Select
import { createSignal, For } from "solid-js";
const colors = [
{ id: 1, text: "red" },
{ id: 2, text: "blue" },
{ id: 3, text: "green" },
{ id: 4, text: "gray", isDisabled: true },
];
export default function ColorSelect() {
const [selectedColorId, setSelectedColorId] = createSignal(2);
function handleChange(event) {
setSelectedColorId(event.target.value);
}
return (
<select value={selectedColorId()} onChange={handleChange}>
<For each={colors}>
{(color) => (
<option value={color.id} disabled={color.isDisabled}>
{color.text}
</option>
)}
</For>
</select>
);
}
static const colors = [
{ id: 1, text: "red" },
{ id: 2, text: "blue" },
{ id: 3, text: "green" },
{ id: 4, text: "gray", isDisabled: true },
];
<let/selectedColorId=2>
<select value:=selectedColorId>
<for|{ id, isDisabled, text }| of=colors>
<option value=id disabled=isDisabled>
${text}
</option>
</for>
</select>
Webapp features
Render app
Fetch data
import { createResource, For, Switch, Match } from "solid-js";
async function fetchUsers() {
return (await fetch("https://randomuser.me/api/?results=3")).json();
}
export default function App() {
const [data] = createResource(fetchUsers);
const users = () => data()?.results;
return (
<Switch>
<Match when={data.loading}>
<p>Fetching users...</p>
</Match>
<Match when={data.error}>
<p>An error occurred while fetching users</p>
</Match>
<Match when={users()}>
<ul>
<For each={users()}>
{(user) => (
<li>
<img src={user.picture.thumbnail} alt="user" />
<p>
{user.name.first} {user.name.last}
</p>
</li>
)}
</For>
</ul>
</Match>
</Switch>
);
}
<try>
<await|{ results: users }|=fetch("https://randomuser.me/api/?results=3").then(res => res.json())>
<ul>
<for|{ picture, name }| of=users>
<li>
<img src=picture.thumbnail alt="user">
<p>${name.first} ${name.last}</p>
</li>
</for>
</ul>
</await>
<@placeholder>
<p>Fetching users...</p>
</@placeholder>
<@catch|error|>
<p>An error occurred while fetching users</p>
</@catch>
</try>