Reactivity

Declare state

logo of Solid.js Solid.js

import { createSignal } from "solid-js";

export default function Name() {
  const [name] = createSignal("John");

  return <h1>Hello {name()}</h1>;
}

logo of Marko Marko

<let/name="John">
<h1>Hello ${name}</h1>

Update state

logo of Solid.js Solid.js

import { createSignal } from "solid-js";

export default function Name() {
  const [name, setName] = createSignal("John");
  setName("Jane");

  return <h1>Hello {name()}</h1>;
}

logo of Marko Marko

<let/name="John">
<script>name = "Jane"</script>
<h1>Hello ${name}</h1>

Computed state

logo of Solid.js Solid.js

import { createSignal } from "solid-js";

export default function DoubleCount() {
  const [count] = createSignal(10);
  const doubleCount = () => count() * 2;

  return <div>{doubleCount()}</div>;
}

logo of Marko Marko

<let/count=10>
<const/doubleCount=count * 2>
<div>${doubleCount}</div>

Templating

Minimal template

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export default function HelloWorld() {
  return <h1>Hello World!</h1>;
}

logo of Marko Marko

<h1>Hello world</h1>

Styling

logo of Solid.js Solid.js

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>
    </>
  );
}

logo of Marko Marko

<h1.title>I am red</h1>
<button style={ "font-size": "10rem" }>I am a button</button>
<button class=scopedButton>I am a style-scoped button</button>

<style>
  .title {
    color: red;
  }
</style>
<style/{ scopedButton }>
  .scopedButton {
    font-size: 10rem;
  }
</style>

Loop

logo of Solid.js Solid.js

import { For } from "solid-js";

export default function Colors() {
  const colors = ["red", "green", "blue"];

  return (
    <ul>
      <For each={colors}>{(color) => <li>{color}</li>}</For>
    </ul>
  );
}

logo of Marko Marko

<ul>
  <for|color| of=["red", "green", "blue"]>
    <li>${color}</li>
  </for>
</ul>

Event click

logo of Solid.js Solid.js

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>
    </>
  );
}

logo of Marko Marko

<let/count=0>
<p>Counter: ${count}</p>
<button onClick() { count++ }>+1</button>

Dom ref

logo of Solid.js Solid.js

import { onMount } from "solid-js";

export default function InputFocused() {
  let inputElement;

  onMount(() => inputElement.focus());

  return <input ref={inputElement} type="text" />;
}

logo of Marko Marko

<input/inputElement>
<script>
  inputElement().focus();
</script>

Conditional

logo of Solid.js Solid.js

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>
    </>
  );
}

logo of Marko Marko

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

logo of Solid.js Solid.js

import { createSignal, onMount } from "solid-js";

export default function PageTitle() {
  const [pageTitle, setPageTitle] = createSignal("");

  onMount(() => {
    setPageTitle(document.title);
  });

  return <p>Page title: {pageTitle()}</p>;
}

logo of Marko Marko

<let/pageTitle="">
<script>pageTitle = document.title</script>
<p>Page title: ${pageTitle}</p>

On unmount

logo of Solid.js Solid.js

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>;
}

logo of Marko Marko

<let/time=new Date()>
<script>
  const id = setInterval(() => time = new Date(), 1000);
  $signal.onabort = () => clearInterval(id)
</script>
<p>Current time: ${time.toLocaleTimeString()}</p>

Component composition

Props

logo of Solid.js Solid.js

import UserProfile from "./UserProfile.jsx";

export default function App() {
  return (
    <UserProfile
      name="John"
      age={20}
      favouriteColors={["green", "blue", "red"]}
      isAvailable
    />
  );
}

logo of Marko Marko

<UserProfile
  name="John"
  age=20
  favouriteColors=["green", "blue", "red"]
  isAvailable
/>

Emit to parent

logo of Solid.js Solid.js

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>
    </>
  );
}

logo of Marko Marko

<let/isHappy=true>
<p>Are you happy?</p>
<AnswerButton
  onYes() { isHappy = true }
  onNo() { isHappy = false }
/>
<p style={ "font-size": 50 }>${isHappy ? "😀" : "😥"}</p>

Slot

logo of Solid.js Solid.js

import FunnyButton from "./FunnyButton.jsx";

export default function App() {
  return <FunnyButton>Click me!</FunnyButton>;
}

logo of Marko Marko

<FunnyButton>Click me!</FunnyButton>

Slot fallback

logo of Solid.js Solid.js

import FunnyButton from "./FunnyButton.jsx";

export default function App() {
  return (
    <>
      <FunnyButton />
      <FunnyButton>I got content!</FunnyButton>
    </>
  );
}

logo of Marko Marko

<FunnyButton/>
<FunnyButton>I got content!</FunnyButton>

Context

logo of Solid.js Solid.js

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>
    </>
  );
}

logo of Marko Marko

<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

logo of Solid.js Solid.js

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} />
    </>
  );
}

logo of Marko Marko

<let/text="Hello world">
<p>${text}</p>
<input value:=text>

Checkbox

logo of Solid.js Solid.js

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>
    </>
  );
}

logo of Marko Marko

<input#is-available
  type="checkbox"
  checked:=input.isAvailable
>
<label for="is-available">Is available</label>

Radio

logo of Solid.js Solid.js

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>
    </>
  );
}

logo of Marko Marko

<let/picked="red">

<div>Picked: ${picked}</div>
<input#blue-pill
  type="radio"
  value="blue"
  checkedValue:=picked
>
<label for="blue-pill">Blue pill</label>

<input#red-pill
  type="radio"
  value="red"
  checkedValue:=picked
>
<label for="red-pill">Red pill</label>

Select

logo of Solid.js Solid.js

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>
  );
}

logo of Marko Marko

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

logo of Solid.js Solid.js

<!doctype html>
<html>
  <body>
    <div id="app"></div>
    <script type="module" src="./main.jsx"></script>
  </body>
</html>

logo of Marko Marko

<!doctype html>
<html>
  <body>
    <div id="app"></div>
    <script type="module" src="./app.js"></script>
  </body>
</html>

Fetch data

logo of Solid.js Solid.js

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>
  );
}

logo of Marko Marko

<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>