with-react.mdx

title	description
Build a User Management App with React	Learn how to use Supabase in your React App.

If you get stuck while working through this guide, refer to the full example on GitHub.

Building the app

Let's start building the React app from scratch.

Initialize a React app

We can use Vite to initialize an app called supabase-react:

npm create vite@latest supabase-react -- --template react
cd supabase-react

Then let's install the only additional dependency: supabase-js.

npm install @supabase/supabase-js

And finally we want to save the environment variables in a .env.local file. All we need are the API URL and the key that you copied earlier.

VITE_SUPABASE_URL=YOUR_SUPABASE_URL
VITE_SUPABASE_ANON_KEY=YOUR_SUPABASE_ANON_KEY

Now that we have the API credentials in place, let's create a helper file to initialize the Supabase client. These variables will be exposed on the browser, and that's completely fine since we have Row Level Security enabled on our Database.

Create and edit src/supabaseClient.js:

import { createClient } from '@supabase/supabase-js'

const supabaseUrl = import.meta.env.VITE_SUPABASE_URL
const supabaseAnonKey = import.meta.env.VITE_SUPABASE_ANON_KEY

export const supabase = createClient(supabaseUrl, supabaseAnonKey)

App styling (optional)

An optional step is to update the CSS file src/index.css to make the app look nice. You can find the full contents of this file here.

Set up a login component

Let's set up a React component to manage logins and sign ups. We'll use Magic Links, so users can sign in with their email without using passwords.

Create and edit src/Auth.jsx:

import { useState } from 'react'
import { supabase } from './supabaseClient'

export default function Auth() {
  const [loading, setLoading] = useState(false)
  const [email, setEmail] = useState('')

  const handleLogin = async (event) => {
    event.preventDefault()

    setLoading(true)
    const { error } = await supabase.auth.signInWithOtp({ email })

    if (error) {
      alert(error.error_description || error.message)
    } else {
      alert('Check your email for the login link!')
    }
    setLoading(false)
  }

  return (
    <div className="row flex flex-center">
      <div className="col-6 form-widget">
        <h1 className="header">Supabase + React</h1>
        <p className="description">Sign in via magic link with your email below</p>
        <form className="form-widget" onSubmit={handleLogin}>
          <div>
            <input
              className="inputField"
              type="email"
              placeholder="Your email"
              value={email}
              required={true}
              onChange={(e) => setEmail(e.target.value)}
            />
          </div>
          <div>
            <button className={'button block'} disabled={loading}>
              {loading ? <span>Loading</span> : <span>Send magic link</span>}
            </button>
          </div>
        </form>
      </div>
    </div>
  )
}

Account page

After a user is signed in we can allow them to edit their profile details and manage their account.

Let's create a new component for that called src/Account.jsx.

import { useState, useEffect } from 'react'
import { supabase } from './supabaseClient'

export default function Account({ session }) {
  const [loading, setLoading] = useState(true)
  const [username, setUsername] = useState(null)
  const [website, setWebsite] = useState(null)
  const [avatar_url, setAvatarUrl] = useState(null)

  useEffect(() => {
    let ignore = false
    async function getProfile() {
      setLoading(true)
      const { user } = session

      const { data, error } = await supabase
        .from('profiles')
        .select(`username, website, avatar_url`)
        .eq('id', user.id)
        .single()

      if (!ignore) {
        if (error) {
          console.warn(error)
        } else if (data) {
          setUsername(data.username)
          setWebsite(data.website)
          setAvatarUrl(data.avatar_url)
        }
      }

      setLoading(false)
    }

    getProfile()

    return () => {
      ignore = true
    }
  }, [session])

  async function updateProfile(event, avatarUrl) {
    event.preventDefault()

    setLoading(true)
    const { user } = session

    const updates = {
      id: user.id,
      username,
      website,
      avatar_url: avatarUrl,
      updated_at: new Date(),
    }

    const { error } = await supabase.from('profiles').upsert(updates)

    if (error) {
      alert(error.message)
    } else {
      setAvatarUrl(avatarUrl)
    }
    setLoading(false)
  }

  return (
    <form onSubmit={updateProfile} className="form-widget">
      <div>
        <label htmlFor="email">Email</label>
        <input id="email" type="text" value={session.user.email} disabled />
      </div>
      <div>
        <label htmlFor="username">Name</label>
        <input
          id="username"
          type="text"
          required
          value={username || ''}
          onChange={(e) => setUsername(e.target.value)}
        />
      </div>
      <div>
        <label htmlFor="website">Website</label>
        <input
          id="website"
          type="url"
          value={website || ''}
          onChange={(e) => setWebsite(e.target.value)}
        />
      </div>

      <div>
        <button className="button block primary" type="submit" disabled={loading}>
          {loading ? 'Loading ...' : 'Update'}
        </button>
      </div>

      <div>
        <button className="button block" type="button" onClick={() => supabase.auth.signOut()}>
          Sign Out
        </button>
      </div>
    </form>
  )
}

Launch!

Now that we have all the components in place, let's update src/App.jsx:

import './App.css'
import { useState, useEffect } from 'react'
import { supabase } from './supabaseClient'
import Auth from './Auth'
import Account from './Account'

function App() {
  const [session, setSession] = useState(null)

  useEffect(() => {
    supabase.auth.getSession().then(({ data: { session } }) => {
      setSession(session)
    })

    supabase.auth.onAuthStateChange((_event, session) => {
      setSession(session)
    })
  }, [])

  return (
    <div className="container" style={{ padding: '50px 0 100px 0' }}>
      {!session ? <Auth /> : <Account key={session.user.id} session={session} />}
    </div>
  )
}

export default App

Once that's done, run this in a terminal window:

npm run dev

And then open the browser to localhost:5173 and you should see the completed app.

Bonus: Profile photos

Every Supabase project is configured with Storage for managing large files like photos and videos.

Create an upload widget

Let's create an avatar for the user so that they can upload a profile photo. We can start by creating a new component:

Create and edit src/Avatar.jsx:

import { useEffect, useState } from 'react'
import { supabase } from './supabaseClient'

export default function Avatar({ url, size, onUpload }) {
  const [avatarUrl, setAvatarUrl] = useState(null)
  const [uploading, setUploading] = useState(false)

  useEffect(() => {
    if (url) downloadImage(url)
  }, [url])

  async function downloadImage(path) {
    try {
      const { data, error } = await supabase.storage.from('avatars').download(path)
      if (error) {
        throw error
      }
      const url = URL.createObjectURL(data)
      setAvatarUrl(url)
    } catch (error) {
      console.log('Error downloading image: ', error.message)
    }
  }

  async function uploadAvatar(event) {
    try {
      setUploading(true)

      if (!event.target.files || event.target.files.length === 0) {
        throw new Error('You must select an image to upload.')
      }

      const file = event.target.files[0]
      const fileExt = file.name.split('.').pop()
      const fileName = `${Math.random()}.${fileExt}`
      const filePath = `${fileName}`

      const { error: uploadError } = await supabase.storage.from('avatars').upload(filePath, file)

      if (uploadError) {
        throw uploadError
      }

      onUpload(event, filePath)
    } catch (error) {
      alert(error.message)
    } finally {
      setUploading(false)
    }
  }

  return (
    <div>
      {avatarUrl ? (
        <img
          src={avatarUrl}
          alt="Avatar"
          className="avatar image"
          style={{ height: size, width: size }}
        />
      ) : (
        <div className="avatar no-image" style={{ height: size, width: size }} />
      )}
      <div style={{ width: size }}>
        <label className="button primary block" htmlFor="single">
          {uploading ? 'Uploading ...' : 'Upload'}
        </label>
        <input
          style={{
            visibility: 'hidden',
            position: 'absolute',
          }}
          type="file"
          id="single"
          accept="image/*"
          onChange={uploadAvatar}
          disabled={uploading}
        />
      </div>
    </div>
  )
}

Add the new widget

And then we can add the widget to the Account page at src/Account.jsx:

// Import the new component
import Avatar from './Avatar'

// ...

return (
  <form onSubmit={updateProfile} className="form-widget">
    {/* Add to the body */}
    <Avatar
      url={avatar_url}
      size={150}
      onUpload={(event, url) => {
        updateProfile(event, url)
      }}
    />
    {/* ... */}
  </form>
)

At this stage you have a fully functional application!