Quickstart: React
This example provides the steps to build a basic user management app. It includes:
- Supabase Database: a Postgres database for storing your user data.
- Supabase Auth: users can sign in with magic links (no passwords, only email).
- Supabase Storage: users can upload a photo.
- Row Level Security: data is protected so that individuals can only access their own data.
- Instant APIs: APIs will be automatically generated when you create your database tables.
By the end of this guide you'll have an app which allows users to login and update some basic profile details:
GitHub#
Should you get stuck while working through the guide, refer to this repo.
Project set up
Before we start building we're going to set up our Database and API. This is as simple as starting a new Project in Supabase and then creating a "schema" inside the database.
Create a project#
- Go to app.supabase.com.
- Click on "New Project".
- Enter your project details.
- Wait for the new database to launch.
Set up the database schema#
Now we are going to set up the database schema. We can use the "User Management Starter" quickstart in the SQL Editor, or you can just copy/paste the SQL from below and run it yourself.
- Go to the SQL Editor page in the Dashboard.
- Click User Management Starter.
- Click Run.
Get the API Keys#
Now that you've created some database tables, you are ready to insert data using the auto-generated API.
We just need to get the URL and anon
key from the API settings.
- Go to the Settings page in the Dashboard.
- Click API in the sidebar.
- Find your API
URL
,anon
, andservice_role
keys on this page.
Building the App#
Let's start building the React app from scratch.
Initialize a React app#
We can use Create React App to initialize
an app called supabase-react
:
1npx create-react-app supabase-react 2cd supabase-react
Then let's install the only additional dependency: supabase-js.
1npm 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 anon
key that you copied earlier.
1REACT_APP_SUPABASE_URL=YOUR_SUPABASE_URL 2REACT_APP_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 = process.env.REACT_APP_SUPABASE_URL const supabaseAnonKey = process.env.REACT_APP_SUPABASE_ANON_KEY export const supabase = createClient(supabaseUrl, supabaseAnonKey)
And one 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.js
:
import { useState } from 'react'
import { supabase } from './supabaseClient'
export default function Auth() {
const [loading, setLoading] = useState(false)
const [email, setEmail] = useState('')
const handleLogin = async (e) => {
e.preventDefault()
try {
setLoading(true)
const { error } = await supabase.auth.signInWithOtp({ email })
if (error) throw error
alert('Check your email for the login link!')
} catch (error) {
alert(error.error_description || error.message)
} finally {
setLoading(false)
}
}
return (
<div className="row flex-center flex">
<div className="col-6 form-widget" aria-live="polite">
<h1 className="header">Supabase + React</h1>
<p className="description">Sign in via magic link with your email below</p>
{loading ? (
'Sending magic link...'
) : (
<form onSubmit={handleLogin}>
<label htmlFor="email">Email</label>
<input
id="email"
className="inputField"
type="email"
placeholder="Your email"
value={email}
onChange={(e) => setEmail(e.target.value)}
/>
<button className="button block" aria-live="polite">
Send magic link
</button>
</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.js
.
import { useState, useEffect } from 'react'
import { supabase } from './supabaseClient'
const Account = ({ session }) => {
const [loading, setLoading] = useState(true)
const [username, setUsername] = useState(null)
const [website, setWebsite] = useState(null)
const [avatar_url, setAvatarUrl] = useState(null)
useEffect(() => {
getProfile()
}, [session])
const getProfile = async () => {
try {
setLoading(true)
const { user } = session
let { data, error, status } = await supabase
.from('profiles')
.select(`username, website, avatar_url`)
.eq('id', user.id)
.single()
if (error && status !== 406) {
throw error
}
if (data) {
setUsername(data.username)
setWebsite(data.website)
setAvatarUrl(data.avatar_url)
}
} catch (error) {
alert(error.message)
} finally {
setLoading(false)
}
}
const updateProfile = async (e) => {
e.preventDefault()
try {
setLoading(true)
const { user } = session
const updates = {
id: user.id,
username,
website,
avatar_url,
updated_at: new Date(),
}
let { error } = await supabase.from('profiles').upsert(updates)
if (error) {
throw error
}
} catch (error) {
alert(error.message)
} finally {
setLoading(false)
}
}
return (
<div aria-live="polite">
{loading ? (
'Saving ...'
) : (
<form onSubmit={updateProfile} className="form-widget">
<div>Email: {session.user.email}</div>
<div>
<label htmlFor="username">Name</label>
<input
id="username"
type="text"
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 primary block" disabled={loading}>
Update profile
</button>
</div>
</form>
)}
<button type="button" className="button block" onClick={() => supabase.auth.signOut()}>
Sign Out
</button>
</div>
)
}
export default Account
Launch!#
Now that we have all the components in place, let's update src/App.js
:
import './index.css'
import { useState, useEffect } from 'react'
import { supabase } from './supabaseClient'
import Auth from './Auth'
import Account from './Account'
export default 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>
)
}
Once that's done, run this in a terminal window:
1npm start
And then open the browser to localhost:3000 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.js
:
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])
const downloadImage = async (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)
}
}
const uploadAvatar = async (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 = `${fileName}`
let { error: uploadError } = await supabase.storage.from('avatars').upload(filePath, file)
if (uploadError) {
throw uploadError
}
onUpload(filePath)
} catch (error) {
alert(error.message)
} finally {
setUploading(false)
}
}
return (
<div style={{ width: size }} aria-live="polite">
<img
src={avatarUrl ? avatarUrl : `https://place-hold.it/${size}x${size}`}
alt={avatarUrl ? 'Avatar' : 'No image'}
className="avatar image"
style={{ height: size, width: size }}
/>
{uploading ? (
'Uploading...'
) : (
<>
<label className="button primary block" htmlFor="single">
Upload an avatar
</label>
<div className="visually-hidden">
<input
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.js
:
// 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={(url) => { setAvatarUrl(url) updateProfile({ username, website, avatar_url: url }) }} /> {/* ... */} </div> )
Storage management#
If you upload additional profile photos, they'll accumulate
in the avatars
bucket because of their random names with only the latest being referenced
from public.profiles
and the older versions getting orphaned.
To automatically remove obsolete storage objects, extend the database
triggers. Note that it is not sufficient to delete the objects from the
storage.objects
table because that would orphan and leak the actual storage objects in
the S3 backend. Instead, invoke the storage API within Postgres via the http
extension.
Enable the http extension for the extensions
schema in the Dashboard.
Then, define the following SQL functions in the SQL Editor to delete
storage objects via the API:
create or replace function delete_storage_object(bucket text, object text, out status int, out content varchar) returns record language 'plpgsql' security definer as $$ declare project_url varchar := '<YOURPROJECTURL>'; service_role_key varchar := '<YOURSERVICEROLEKEY>'; -- full access needed url varchar := project_url||'/storage/v1/object/'||bucket||'/'||object; begin select into status, content result.status::int, result.content::varchar FROM extensions.http(( 'DELETE', url, ARRAY[extensions.http_header('authorization','Bearer '||service_role_key)], NULL, NULL)::extensions.http_request) as result; end; $$; create or replace function delete_avatar(avatar_url text, out status int, out content varchar) returns record language 'plpgsql' security definer as $$ begin select into status, content result.status, result.content from public.delete_storage_object('avatars', avatar_url) as result; end; $$;
Next, add a trigger that removes any obsolete avatar whenever the profile is updated or deleted:
create or replace function delete_old_avatar() returns trigger language 'plpgsql' security definer as $$ declare status int; content varchar; begin if coalesce(old.avatar_url, '') <> '' and (tg_op = 'DELETE' or (old.avatar_url <> new.avatar_url)) then select into status, content result.status, result.content from public.delete_avatar(old.avatar_url) as result; if status <> 200 then raise warning 'Could not delete avatar: % %', status, content; end if; end if; if tg_op = 'DELETE' then return old; end if; return new; end; $$; create trigger before_profile_changes before update of avatar_url or delete on public.profiles for each row execute function public.delete_old_avatar();
Finally, delete the public.profile
row before a user is deleted.
If this step is omitted, you won't be able to delete users without
first manually deleting their avatar image.
create or replace function delete_old_profile() returns trigger language 'plpgsql' security definer as $$ begin delete from public.profiles where id = old.id; return old; end; $$; create trigger before_delete_user before delete on auth.users for each row execute function public.delete_old_profile();
Next steps#
At this stage you have a fully functional application!
- Got a question? Ask here.
- Sign in: app.supabase.com