Getting started with SolidJS

#Automatic Setup With Create Instant App

The fastest way to get started with Instant and SolidJS is to use create-instant-app to scaffold a new project with Instant already set up.

To get started, run:

npx create-instant-app -b solidjs-vite

#Manual Setup

Create a blank Vite SolidJS App:

npx create-vite@latest -t solid-ts

Add the InstantDB SolidJS Library:

npm i @instantdb/solidjs

Use instant-cli to set up a new Instant project. This will prompt you to log in if you haven't already. It will then create schema and permissions files and update your .env file.

npx instant-cli init

Create a database client in src/lib/db.ts:

src/lib/db.ts

import { init } from '@instantdb/solidjs';
import schema from '../instant.schema';
 
export const db = init({
  appId: import.meta.env.VITE_INSTANT_APP_ID!,
  schema,
  useDateObjects: true,
});

You're now ready to run queries and transactions against your database!

#Creating a To-Do List App

Let's add a "todo" entity to our schema file at src/instant.schema.ts:

src/instant.schema.ts

import { i } from '@instantdb/solidjs';
 
const _schema = i.schema({
  entities: {
    $files: i.entity({
      path: i.string().unique().indexed(),
      url: i.string(),
    }),
    $users: i.entity({
      email: i.string().unique().indexed().optional(),
      imageURL: i.string().optional(),
      type: i.string().optional(),
    }),
    todos: i.entity({
      text: i.string(),
      done: i.boolean(),
      createdAt: i.date(),
    }),
  },
  links: {
    $usersLinkedPrimaryUser: {
      forward: {
        on: '$users',
        has: 'one',
        label: 'linkedPrimaryUser',
        onDelete: 'cascade',
      },
      reverse: {
        on: '$users',
        has: 'many',
        label: 'linkedGuestUsers',
      },
    },
  },
  rooms: {},
});
 
//...

Push the schema:

npx instant-cli push

Replace the content of src/App.tsx with the following:

src/App.tsx

import { id, type InstaQLEntity } from "@instantdb/solidjs";
import { createSignal, For, Show, type Component } from "solid-js";
import { db } from "./lib/db";
import type { AppSchema } from "./instant.schema";
 
type Todo = InstaQLEntity<AppSchema, "todos">;
 
const App: Component = () => {
  const state = db.useQuery({ todos: {} });
  const todos = () => state().data?.todos ?? [];
 
  return (
    <Show when={!state().isLoading}>
      <Show
        when={!state().error}
        fallback={
          <div class="text-red-500 p-4">Error: {state().error?.message}</div>
        }
      >
        <div class="p-8 grid-cols-2 items-start gap-2 grid">
          <Welcome />
          <div class="bg-white rounded-lg p-6 border border-neutral-200 shadow flex flex-col">
            <h2 class="tracking-wide text-[#F54A00] text-2xl">Todos</h2>
            <div class="text-xs pb-4">
              Open another tab to see todos update in realtime!
            </div>
            <div class="border rounded border-neutral-300">
              <TodoForm />
              <TodoList todos={todos()} />
              <ActionBar todos={todos()} />
            </div>
          </div>
        </div>
      </Show>
    </Show>
  );
};
 
function addTodo(text: string) {
  db.transact(
    db.tx.todos[id()].update({
      text,
      done: false,
      createdAt: Date.now(),
    }),
  );
}
 
function deleteTodo(todo: Todo) {
  db.transact(db.tx.todos[todo.id].delete());
}
 
function toggleDone(todo: Todo) {
  db.transact(db.tx.todos[todo.id].update({ done: !todo.done }));
}
 
function deleteCompleted(todos: Todo[]) {
  const completed = todos.filter((todo) => todo.done);
  if (completed.length === 0) return;
  const txs = completed.map((todo) => db.tx.todos[todo.id].delete());
  db.transact(txs);
}
 
function TodoForm() {
  const [text, setText] = createSignal("");
  return (
    <div class="flex items-center h-10 border-neutral-300">
      <form
        class="flex-1 h-full"
        onSubmit={(e) => {
          e.preventDefault();
          if (!text()) return;
          addTodo(text());
          setText("");
        }}
      >
        <input
          value={text()}
          onInput={(e) => setText(e.currentTarget.value)}
          class="w-full h-full placeholder-neutral-300 px-2 outline-none bg-transparent"
          autofocus
          placeholder="What needs to be done?"
          type="text"
          name="input"
        />
      </form>
    </div>
  );
}
 
function TodoList(props: { todos: Todo[] }) {
  return (
    <div class="divide-y divide-neutral-300">
      <For each={props.todos}>
        {(todo) => (
          <div class="flex items-center h-10">
            <div class="h-full px-2 flex items-center justify-center">
              <div class="w-5 h-5 flex items-center justify-center">
                <input
                  type="checkbox"
                  class="cursor-pointer"
                  checked={todo.done}
                  onChange={() => toggleDone(todo)}
                />
              </div>
            </div>
            <div class="flex-1 px-2 overflow-hidden flex items-center">
              <span classList={{ "line-through": todo.done }}>{todo.text}</span>
            </div>
            <button
              class="h-full px-2 flex items-center justify-center text-neutral-300 hover:text-neutral-500"
              onClick={() => deleteTodo(todo)}
            >
              X
            </button>
          </div>
        )}
      </For>
    </div>
  );
}
 
function ActionBar(props: { todos: Todo[] }) {
  return (
    <div class="flex justify-between items-center h-10 px-2 text-xs border-t border-neutral-300">
      <div>
        Remaining todos: {props.todos.filter((todo) => !todo.done).length}
      </div>
      <button
        class=" text-neutral-300 hover:text-neutral-500"
        onClick={() => deleteCompleted(props.todos)}
      >
        Delete Completed
      </button>
    </div>
  );
}
 
function Welcome() {
  return (
    <div class="bg-white p-6 rounded-lg border border-neutral-200 shadow flex justify-center flex-col gap-2">
      <h2 class="tracking-wide text-[#F54A00] text-2xl text-center">
        Solid + Vite + InstantDB
      </h2>
      <div class="grid grid-cols-1 md:grid-cols-2 grow gap-2">
        <a
          href="https://docs.solidjs.com/"
          target="_blank"
          rel="noopener noreferrer"
          class="border hover:bg-neutral-100 py-8 shadow flex flex-col gap-2 items-center justify-center font-semibold border-neutral-200 rounded"
        >
          <img
            src="https://www.solidjs.com/img/logo/without-wordmark/logo.svg"
            width={34}
          />
          Solid Docs
        </a>
        <a
          target="_blank"
          href="https://www.instantdb.com/docs"
          rel="noopener noreferrer"
          class="border shadow flex flex-col py-8 gap-2 hover:bg-neutral-100 items-center justify-center font-semibold border-neutral-200 rounded"
        >
          <img
            src="https://www.instantdb.com/img/icon/logo-512.svg"
            width={34}
          />
          Instant Docs
        </a>
      </div>
    </div>
  );
}
 
export default App;

Go to localhost:5173, and huzzah 🎉 You've got a fully functional todo list running!

#Reactivity

In Solid, query results are returned as Signals. This means that they cannot be destructured without preserving reactivity.

Incorrect Usage:

// ❌ Data cannot be destructured from an Accessor
const { data } = db.useQuery({ todos: {} });
 
// ❌ state().data() must be called from a Tracking Scope
const state = db.useQuery({ todos: {} });
const todos = state().data().todos;

Correct Usage:

// ✅ state().data() can be called in JSX
const TodoCount = () => {
  const state = db.useQuery({ todos: {} });
 
  return (
    <div>{state().data()?.todos.length} todos</div>
  )
}

Alternatively:

// ✅ Create a new signal for todos
const TodoCount = () => {
  const state = db.useQuery({ todos: {} });
  const todos = () => state().data?.todos ?? [];
 
  return (
    <div>{todos().length} todos</div>
  )
}

Transactions in Solid work the same way they do in React via db.transact. To learn more, see our writing data docs.

instant

instant

Pick your app

#Automatic Setup With Create Instant App

#Manual Setup

#Creating a To-Do List App

#Reactivity