Remix with Database integration

How to use Remix and Supabase for CRUD operations

Saturday, November 27, 2021

integration

Table of Contents

TL;DR

Link to the source code

Here's a live demo

UPDATE: After implementing authentication, the link above has only view access.

Here's the demo with authentication

Preface

This post will be the first part of the series on how I will create the entire application. So I will start with a boring introduction about the motivation for this series.


I have chosen Supabase to store my data as it allows me to focus on the Frontend part due to Supabase's easy-to-use API. You can use any provider of your choice, or you can even create your custom backend.

This part of the series will focus on how to use Remix for CRUD operations.


Basic overview of the app

The Vocabulary section will consist of lists of words that are publicly available and a protected admin route to perform a CRUD operation.

Here are the properties we need for each word:


Prerequisites if you want to follow along

If you are not yet familiar with Remix, I suggest checking first my previous blog post about it, or refer to their documentation.


Create a Supabase project

If you want to use another provider, you can skip to this part Create the Remix project

Refer to their official documentation on how to create a Supabase project.


After creating your account, go to SQL Editor tab and execute the queries below:

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Create words table

sql
CREATE TABLE words ( id bigint GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY, name varchar NOT NULL, definitions varchar ARRAY NOT NULL, sentences varchar ARRAY NOT NULL, type varchar NOT NULL);

Add a new word

sql
INSERT INTO words (name, type, definitions, sentences)VALUES ('hello', 'noun', ARRAY['used as a greeting'], ARRAY['Hello world.']);

In the Table Editor tab, you should see the new entry.

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Add anonymous access

sql
ALTER TABLE words ENABLE ROW LEVEL SECURITY; CREATE POLICY "anon_select" ON public.words FOR SELECT USING ( auth.role() = 'anon'); CREATE POLICY "anon_insert" ON public.words FOR INSERT WITH CHECK ( auth.role() = 'anon'); CREATE POLICY "anon_update" ON public.words FOR UPDATE USING ( auth.role() = 'anon'); CREATE POLICY "anon_delete" ON public.words FOR DELETE USING ( auth.role() = 'anon');

Lastly, in Authentication/Policies tab, should be seeing this.

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Create a Remix project


Installation

sh
npx create-remix@latestcd [whatever you named the project]

Cleaning up

sh
# Remove demo filesrm -rf app/routes/demos app/styles/demos # We'll recreate this files laterrm app/routes/index.tsx app/root.tsx

Re-create file root.tsx file under app folder.

app/root.tsx
12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667import {LiveReload,Meta,Outlet,Scripts,ScrollRestoration,useCatch} from "remix"; export default function App() { return ( <Document> <Layout> <Outlet /> </Layout> </Document> );} function Document({ children, title,}: { children: React.ReactNode; title?: string;}) { return ( <html lang="en"> <head> <meta charSet="utf-8" /> <meta name="viewport" content="width=device-width,initial-scale=1" /> {title ? <title>{title}</title> : null} <Meta /> </head> <body> {children} <ScrollRestoration /> <Scripts /> {process.env.NODE_ENV === "development" && <LiveReload />} </body> </html> );} function Layout({children}: React.PropsWithChildren<{}>) { return ( <article>{children}</article> );} export function CatchBoundary() { let caught = useCatch(); let message; switch (caught.status) { case 404: message = <p>This is a custom error message for 404 pages</p> break; // You can customize the behavior for other status codes default: throw new Error(caught.data || caught.statusText); } return ( <Document title={`${caught.status} ${caught.statusText}`}> <Layout> <h1> {caught.status}: {caught.statusText} </h1> {message} </Layout> </Document> );}

Re-create file index.tsx file under app/routes folder.

app/routes/index.tsx
1234567export default function Index() { return ( <div> <h1>Hello world</h1> </div> );}

The mandatory hello world page is now ready.

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Expect the design will be terrible. I will create a separate blog for styling.



Integration Prerequisites

Install Supabase javascript library

Not using Supabase? Skip to Fetch All Words


Install Supabase

sh
npm install @supabase/supabase-js # OR yarn add @supabase/supabase-js

Create a Supabase client utility

The next step will allow us to create a Supabase client utility that we can use across the whole application.


Create a .env file to hold your Supabase credentials.

.env
12SUPABASE_ANON_KEY=YOUR_SUPABASE_ANON_KEYSUPABASE_URL=YOUR_SUPABASE_URL

Make sure to add .env in the .gitignore file.

Create a Supabase client utility for reusability

libs/supabase-client.ts
123456import { createClient } from "@supabase/supabase-js"; const supabaseUrl = process.env.SUPABASE_URL as string;const supabaseKey = process.env.SUPABASE_ANON_KEY as string; export const supabase = createClient(supabaseUrl, supabaseKey);

Chores before integration


(OPTIONAL)Create type definition

To take advantage of strong typing, I will create a type definition.

If you prefer not to use TypeScript, remove the declarations and usages of types, and change the file extensions from .tsx to .jsx.

app/models/word.ts
12345678910111213export enum WordType { NOUN = "noun", VERB = "verb", ADJECTIVE = "adjective",} export type Word = { id: number; name: string; sentences: string[]; definitions: string[]; type: WordType;};

(OPTIONAL) Redirect / to /words

As I plan to create multiple mini-apps in this project, I'll redirect / to /words, for now. The code below will ensure we don't need to manually navigate to /words every time we open the root page.

app/routes/index.tsx
12345import { redirect } from "remix"; export function loader() { return redirect("/words", 308);}
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Integrating Supabase with Remix

Create the words listing page

If you are not using Supabase, replace the Supabase API calls with your choice.

fetch list of words using Remix's loader


app/routes/words.tsx
12345678910111213import type { LoaderFunction } from "remix";import { supabase } from "~/libs/supabase-client";import { Word } from "~/models/word"; export const loader: LoaderFunction = async () => { const { data: words } = await supabase .from<Word>("words") .select("id,name,type"); // We can pick and choose what we want to display // This can solve the issue of over-fetching or under-fetching return words;};

Create a React component to display the list of words

app/routes/words.tsx
123456789101112131415161718192021222324import { useLoaderData, Link } from "remix"; // export const loader ... export default function Index() { const words = useLoaderData<Word[]>(); return ( <div> <h1>English words I learned</h1> <ul> {words.map((word) => ( <li key={word.id}> <div> <Link to={`/words/${word.id}`}> {word.name} | {word.type} </Link> </div> </li> ))} </ul> </div> );}

The code above will fetch the data from Supabase and display it in a list.

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Create the word details page


Create a file named $id.tsx under app/routes/words folder.


Create the loader function
app/routes/words/$id.tsx
12345678910111213import type { LoaderFunction } from "remix";import { supabase } from "~/libs/supabase-client";import { Word } from "~/models/word"; export const loader: LoaderFunction = async ({ params }) => { const { data } = await supabase .from<Word>("words") .select("*") .eq("id", params.id as string) .single(); return data;};

Create the component
app/routes/words/$id.tsx
123456789101112131415161718192021222324// import ...import { /*other imports*/, useLoaderData } from "remix"; // export const loader ... export default function Word() { const word = useLoaderData<Word>(); return ( <div> <h3> {word.name} | {word.type} </h3> {word.definitions.map((definition, i) => ( <p key={i}> <i>{definition}</i> </p> ))} {word.sentences.map((sentence, i) => ( <p key={i}>{sentence}</p> ))} </div> );}

The image below shows that it still won't show even after creating the /words/[id] route.

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Adding a router Outlet

We need to add an Outlet inside our Words Index component to fix the above issue.

app/routes/words.tsx
1234567891011121314151617181920212223242526import {/*other imports*/, Outlet} from "remix"; // export const loader ... export default function Index() { const words = useLoaderData<Word[]>(); return ( <div> <h1>English words I learned</h1> {/* To put the list and outlet side by side */} <div style={{ display: "flex", justifyContent: "space-between" }}> <ul> {words.map((word) => ( <li key={word.id}> <Link to={`/words/${word.id}`}> {word.name} | {word.type} </Link> </li> ))} </ul> <Outlet /> {/* <-- this is where $id.tsx will render */} </div> </div> );}

After clicking on a word, $id.tsx route will render on where we put the Outlet.

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Delete a word

Since we're already on the /words/$id page, let's proceed with deletion first


Add a button to delete the word

app/routes/words/$id.tsx
1234567891011121314151617import {/*other imports*/, Form} from "remix"; // export const loader ... export default function Index() { // ... return ( <div> {/* previous content */} <Form method="post"> <input type="hidden" name="_method" value="delete" /> <button type="submit">Delete</button> </Form> </div> );}

The image shows a message that we did not define any action to handle the submit event.

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Delete the word in the database using Remix's action

app/routes/words/$id.tsx
1234567891011121314151617import { /*other imports*/, redirect} from "remix";import type {/*other imports*/, ActionFunction} from "remix"; export const action: ActionFunction = async ({ request, params }) => { const formData = await request.formData(); if (formData.get("_method") === "delete") { await supabase .from<Word>("words") .delete() .eq("id", params.id as string); return redirect("/words"); }}; // ...rest of the code

After we click on the delete button, the word hello will be deleted from the database, and the page will redirect to the /words page.

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Explanation:
Why go through all this trouble?

It just happens that this approach does not need any JavaScript to run(try it on your browser). This means our app is interactive even before we load the JavaScript from the server.


Create a new word entry

Now we don't have anything on the list; let's create the route to handle creation.


Create a button in the /words route that will navigate to /words/add

We can use the useNavigate hook here, But for this blog, I'll show you how we can perform the entire CRUD operations without using any JavaScript on the client-side.

app/routes/words.tsx
1234567891011121314151617import { /*other imports*/ Form } from "remix"; // export const loader ... export default function Index() { // const words ... return ( <div> <h1>English words I learned</h1> <Form method="get" action={"/words/add"}> <button type="submit">Add new word</button> </Form> {/* previous contents */} </div> );}

Create the add new word route

To avoid a 404 page, let's create the /words/add route.


Create the component
app/routes/words/add.tsx
12345678910111213141516171819202122232425262728293031323334353637383940import {Form} from "remix";import { WordType } from "~/models/word"; export default function AddWord() { return ( <Form method="post"> <div> <label htmlFor="name">Word</label> <input id="name" name="name" type="text" placeholder="Word" required /> </div> <div> <label htmlFor="type">Type</label> <select id="type" name="type" defaultValue={WordType.NOUN}> <option value={WordType.NOUN}>Noun</option> <option value={WordType.VERB}>Verb</option> <option value={WordType.ADJECTIVE}>Adjective</option> </select> </div> <div> <label htmlFor="sentence.1">Sentences</label> <textarea id="sentence.1" name="sentence" placeholder="Sentence" minLength={10} /> </div> <div> <label htmlFor="definition.1">Definitions</label> <textarea id="definition.1" name="definition" placeholder="Definition" minLength={10} /> </div> <button type="submit">Submit</button> </Form> );}

The image below shows the form we created after clicking on the Add new word button.

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Add an action

To avoid the missing action error after clicking on the Submit button, let's add an action on the words/add route.

app/routes/words/add.tsx
123456789101112131415161718import { /*other imports*/, redirect } from "remix";import type { ActionFunction } from "remix";import { supabase } from "~/libs/supabase-client"; export const action: ActionFunction = async ({ request }) => { const formData = await request.formData(); const newWord = { name: formData.get("name"), type: formData.get("type"), sentences: formData.getAll("sentence"), definitions: formData.getAll("definition"), }; const { data } = await supabase.from("words").insert([newWord]).single(); return redirect(`/words/${data?.id}`);};

After clicking on the Submit button, the word will be added to the database, and the page will redirect to the /words/$id page.

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I'm not sure if you noticed, but we haven't used any JavaScript code on the Frontend, yet it could complete the intended task. We only used an HTML form as it was initially used to handle validations and perform the submission. This is what I like about Remix; we can focus on the web fundamentals to become a better Web developer instead of making some workarounds.


Edit a word entry

Now, to handle the missing operation in our CRUD app, let's add the ability to modify an existing entry.


Create a file named edit.$id.tsx under app/routes/words

When we add a . between words, it will transform to / in the URL. The above example will result in words/edit/[id].


Create a form for editing the word

Refactoring

Since the edit form is very similar to the add form, we can reuse the same form with additional checks to determine if we are adding or editing.

app/components/WordForm.tsx
12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970import { Form } from "remix";import { Word, WordType } from "~/models/word"; export default function WordForm({ word }: { word?: Word }) { return ( <Form method="post"> <div> <label htmlFor="name">Word</label> <input id="name" name="name" type="text" placeholder="Word" required defaultValue={word?.name ?? ""} disabled={Boolean(word?.name)} /> </div> <div> <label htmlFor="type">Type</label> <select id="type" name="type" defaultValue={word?.type ?? WordType.NOUN} > <option value={WordType.NOUN}>Noun</option> <option value={WordType.VERB}>Verb</option> <option value={WordType.ADJECTIVE}>Adjective</option> </select> </div> <div> {word?.sentences.map((sentence, i) => ( <SentenceField index={i + 1} sentence={sentence} key={i} /> )) ?? <SentenceField index={1} sentence={""} />} </div> <div> {word?.definitions.map((definition, i) => ( <DefinitionField index={i + 1} definition={definition} key={i} /> )) ?? <DefinitionField index={1} definition={""} />} </div> <button type="submit">Submit</button> </Form> );} const SentenceField = ({ index, sentence }) => ( <div> <label htmlFor={`sentence.${index}`}>Sentence #{index}</label> <textarea id={`sentence.${index}`} name="sentence" defaultValue={sentence} placeholder={`Sentence #${index}`} minLength={10} /> </div>); const DefinitionField = ({ index, definition }) => ( <div> <label htmlFor={`definition.${index}`}>Definition #{index}</label> <textarea id={`definition.${index}`} name="definition" defaultValue={definition} placeholder={`Definition #${index}`} minLength={10} /> </div>);

That's a lot of code; however, we can reap the benefits of simplifying the code in add.tsx and edit.$id.tsx.

Update routes/words/add.tsx
app/routes/words/add.tsx
12345// other code... export default function AddWord() { return <WordForm />;}
Create routes/words/edit.$id.tsx
app/routes/words/edit.$id.tsx
123456789import { useLoaderData } from "remix";import WordForm from "~/components/WordForm";import { Word } from "~/models/word"; export default function EditWord() { const data = useLoaderData<Word>(); return <WordForm word={data} />;}

Now, we have a reusable form. If we have to make a style change, we can update the WordForm component, reflecting the change on both routes.

NOTE: I'm extracting everything to WordForm.tsx since it is applicable in my use case.

Create a loader for the word details

In order for the edit form to be populated with the existing data, we need to create a loader.

app/routes/words/edit.$id.tsx
1234567891011121314import { supabase } from "~/libs/supabase-client";import type {LoaderFunction} from "remix"; export const loader: LoaderFunction = async ({ params }) => { const { data } = await supabase .from<Word>("words") .select("*") .eq("id", params.id as string) .single(); return data;}; // export const EditWord...

Create a button in the /words/$id page to edit a word

app/routes/words/$id.tsx
1234567891011121314// ... export default function Word() { // const word ... return ( <div> {/* other code... */} <Form method="get" action={`/words/edit/${word.id}`}> <button type="submit">Edit</button> </Form> </div> );}

The image below shows the pre-filled form depending on the content of id in the URL.

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Add an action handler

To handle the form submission, we need to add an action handler.

app/routes/words/edit.$id.tsx
123456789101112131415161718192021import {/*other imports*/, redirect} from "remix";import type {/*other imports*/, ActionFunction} from "remix"; export const action: ActionFunction = async ({ request, params }) => { const formData = await request.formData(); const id = params.id as string; const updates = { type: formData.get("type"), sentences: formData.getAll("sentence"), definitions: formData.getAll("definition"), }; await supabase.from("words").update(updates).eq("id", id); return redirect(`/words/${id}`);}; // export const loader... // export const EditWord...

After modifying some fields and clicking the submit button, the page will redirect to the /words/$id page with the updated data.

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Add indicator for state transition

By utilizing the useTransition hook, we can add or change something on the screen depending on the route's state.

.tsx
123456import {" useTransition } from "remix";" // Somewhere in the route's compnentlet transition = useTransition(); <div>... State: {transition.state}</div>

We can replace the text states below with global loading indicator, local component spinner, disabling elements, etc.

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Extra Demo: CRUD operations without JavaScript

Here's proof that we can perform the CRUD operations without using any JavaScript on the client-side(as indicated by errors in the network tab). Take note that I also simulated a slower network connection, yet the performance is not that terrible.

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I'm not saying we should not use JavaScript on the client-side, as JavaScript can do some cool stuff to help with user experience. For instance, you might notice that the states were stuck in idle.

Conclusion

So far, I'm having a positive experience with the framework. Of course, I'm still learning, but I'm enjoying the process. I'm starting to agree with the Remix team said that if we become better with Remix, we become better with the Web. Working with Remix allows me to refresh my HTML skills that are almost diminishing due to too much dependency on JavaScript. I'm looking forward to using more of their features in the next iteration of this app.

What's next?