logo

Component Party

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 Mithril Mithril

import m from "mithril";

export default function Name() {
  let name = "John";

  return {
    view: () => m("h1", `Hello ${name}`),
  };
}

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 Mithril Mithril

import m from "mithril";

export default function Name() {
  let name = "John";
  name = "Jane";
  return {
    view: () => m("h1", `Hello ${name}`),
  };
}

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 Mithril Mithril

import m from "mithril";

export default function DoubleCount() {
  let count = 10;
  let doubleCount = count * 2;
  return {
    view: () => m("div", doubleCount),
  };
}

Templating

Minimal template

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

logo of Mithril Mithril

import m from "mithril";

export default function HelloWorld() {
  return {
    view: () => m("h1", "Hello World"),
  };
}

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 Mithril Mithril

import "./style.css";
import m from "mithril";

export default function CssStyle() {
  return {
    view: () =>
      m(
        "div",
        m("h1.title", "I am red"),
        m("button", { style: { fontSize: "10rem" } }, "I am a button"),
      ),
  };
}

Loop

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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 Mithril Mithril

import m from "mithril";

export default function Colors() {
  const colors = ["red", "green", "blue"];
  return {
    view: () =>
      m(
        "ul",
        colors.map((color, idx) => m("li", { key: idx }, color)),
      ),
  };
}

Event click

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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 Mithril Mithril

import m from "mithril";

export default function Counter() {
  let count = 0;
  const incrementCount = () => (count = count + 1);
  return {
    view: () =>
      m(
        "div",
        m("p", `Counter: ${count}`),
        m("button", { onclick: incrementCount }, "+1"),
      ),
  };
}

Dom ref

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import { onMount } from "solid-js";

export default function InputFocused() {
  let inputElement;

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

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

logo of Mithril Mithril

import m from "mithril";

export default function InputFocused() {
  let value = "";
  return {
    view: () =>
      m("input", {
        oncreate: ({ dom }) => dom.focus(),
        type: "text",
        value,
        oninput: (e) => (value = e.target.value),
      }),
  };
}

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 Mithril Mithril

import m from "mithril";
const TRAFFIC_LIGHTS = ["red", "orange", "green"];

export default function TrafficLight() {
  let lightIndex = 0;
  let currentLight = () => TRAFFIC_LIGHTS[lightIndex];

  const nextLight = () => (lightIndex + 1) % TRAFFIC_LIGHTS.length;

  const instructions = () => {
    switch (currentLight()) {
      case "red":
        return "STOP";
      case "orange":
        return "SLOW DOWN";
      case "green":
        return "GO";
    }
  };

  return {
    view: () =>
      m(
        "div",
        m("button", { onclick: nextLight }, "Next light"),
        m("p", `Light is: ${currentLight()}`),
        m("p", "You must ", m("span", instructions())),
      ),
  };
}

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 Mithril Mithril

import m from "mithril";

export default function PageTitle() {
  return {
    view: () => m("p", `Page title: ${document.title}`),
  };
}

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 Mithril Mithril

import m from "mithril";

export default function Time() {
  let time = new Date().toLocaleTimeString();

  const timer = setInterval(() => {
    time = new Date().toLocaleTimeString();
    m.redraw();
  }, 1000);

  return {
    view: () => m("p", `Current time: ${time}`),
    onremove: () => clearInterval(timer),
  };
}

Component composition

Props

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import UserProfile from "./UserProfile.jsx";

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

logo of Mithril Mithril

import m from "mithril";
import UserProfile from "./UserProfile.js";

export default function App() {
  return {
    view: () =>
      m(UserProfile, {
        name: "john",
        age: 20,
        favouriteColors: ["green", "blue", "red"],
        isAvailable: true,
      }),
  };
}

Emit to parent

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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 Mithril Mithril

import m from "mithril";
export const AnswerButton = ({ attrs: { onYes, onNo } }) => ({
  view: () =>
    m(
      "div",
      m("button", { onclick: onYes }, "YES"),
      m("button", { onclick: onNo }, "NO"),
    ),
});

Slot

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import FunnyButton from "./FunnyButton.jsx";

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

logo of Mithril Mithril

import m from "mithril";
import { FunnyButton } from "./FunnyButton.jsx";

export default function App() {
  return {
    view: () => m(FunnyButton, "Click me!"),
  };
}

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 Mithril Mithril

import m from "mithril";
import FunnyButton from "./FunnyButton.jsx";

export default function App() {
  return {
    view: () => m("", m(FunnyButton), m(FunnyButton, "I got Content")),
  };
}

Context

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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 Mithril Mithril

import m from "mithril";
import UserProfile from "./UserProfile";

export default function App() {
  const user = {
    id: 1,
    username: "unicorn42",
    email: "[email protected]",
  };

  const updateUsername = (username) => (user.username = username);

  return {
    view: () =>
      m(
        "",
        m("h1", `Welcome Back, ${user.username}`),
        m(UserProfile, { user, updateUsername }),
      ),
  };
}

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 Mithril Mithril

import m from "mithril";

export default function InputHello() {
  let text = "Hello world";
  const handleChange = ({ target: { value } }) => (text = value);

  return {
    view: () =>
      m("", m("p", text), m("input", { value: text, onchange: handleChange })),
  };
}

Checkbox

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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 Mithril Mithril

import m from "mithril";

export default function IsAvailable() {
  let isAvailable = false;
  const onUpdate = () => (isAvailable = !isAvailable);

  return {
    view: () =>
      m(
        "",

        m("input", {
          id: "is-available",
          type: "checkbox",
          checked: isAvailable,
          onchange: onUpdate,
        }),
        m("label", { for: "is-available" }, "Is available"),
      ),
  };
}

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 Mithril Mithril

import m from "mithril";

export default function PickPill() {
  let picked = "red";
  let pills = ["red", "green", "blue"];
  const handleChange = ({ target: { value } }) => (picked = value);

  return {
    view: () =>
      m(
        "",
        m("", `Picked: ${picked}`),
        pills.map((pill) =>
          m(
            ".",
            m("input", {
              id: pill,
              checked: picked == pill,
              type: "radio",
              value: pill,
              onchange: handleChange,
            }),
            m("label", { for: pill }, pill),
          ),
        ),
      ),
  };
}

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 Mithril Mithril

import m from "mithril";
const colors = [
  { id: 1, text: "red" },
  { id: 2, text: "blue" },
  { id: 3, text: "green" },
  { id: 4, text: "gray", isDisabled: true },
];

export default function ColorSelect() {
  let selectedColorId = 2;

  const handleSelect = ({ target: { value } }) => (selectedColorId = value);

  return {
    view: () =>
      m(
        "select",
        { value: selectedColorId, onchange: handleSelect },
        colors.map(({ id, text, isDisabled }) =>
          m("option", { key: id, id, disabled: isDisabled, value: id }, text),
        ),
      ),
  };
}

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 Mithril Mithril

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

import m from "mithril";

export default function App() {
  let isLoading = false;
  let error = null;
  let users = [];

  async function fetchUsers() {
    isLoading = true;
    try {
      const { results } = await m.request(
        "https://randomuser.me/api/?results=3",
      );
      users = results;
    } catch (err) {
      error = err;
    }
    isLoading = false;
  }

  return {
    oninit: fetchUsers,
    view() {
      if (isLoading) return m("p", "Fetching users...");
      if (error) return m("p", "An error occurred while fetching users");
      return users.map((user) =>
        m(
          "li",
          { key: user.login.uuid },
          m("img", { src: user.picture.thumbnail, alt: "user" }),
          m("p", `${user.name.first} ${user.name.last}`),
        ),
      );
    },
  };
}