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John Owolabi Idogun
John Owolabi Idogun

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FullStack JWT Auth: Diving into SvelteKit - Profile Update

#javascript #typescript #webdev #svelte

Introduction

From the last article, we concluded user registeration and authentication flow. It was surreal to me and I hope you find it intriguing too. In this article (possibly the last in this series), we'll look at how authenticated users can update their details.

Source code

The overall source code for this project can be accessed here:

GitHub logo Sirneij / django_svelte_jwt_auth

A robust and secure Authentication and Authorization System built with Django and SvelteKit

django_svelte_jwt_auth

This is the codebase that follows the series of tutorials on building a FullStack JWT Authentication and Authorization System with Django and SvelteKit.

This project was deployed on heroku (backend) and vercel (frontend) and its live version can be accessed here.

To run this application locally, you need to run both the backend and frontend projects. While the latter has some instructions already for spinning it up, the former can be spinned up following the instructions below.

Run locally

To run locally

  • Clone this repo:

     git clone https://github.com/Sirneij/django_svelte_jwt_auth.git

  • Change directory into the backend folder:

     cd backend

  • Create a virtual environment:

     pipenv shell

    You might opt for other dependencies management tools such as virtualenv, poetry, or venv. It's up to you.

  • Install the dependencies:

    pipenv install

  • Make migrations and migrate the database:

     python manage.py makemigrations
 python manage.py migrate

  • Finally, run the application:

     python manage.py runserver
View on GitHub

Live version

This project was deployed on heroku (backend) and vercel (frontend) and its live version can be accessed here.

Notabene

The project's file structure has considerably been modified from where we left off. Also, most of the scripts have be re-written in TypeScript. The concept of SvelteKit environment variables, TypeScript's interfaces, powerful loader, and a host of others were also implemented. We now have the following file structure for the frontend project:

├── package.json
├── package-lock.json
├── README.md
├── src
│   ├── app.d.ts
│   ├── app.html
│   ├── components
│   │   ├── Header
│   │   │   ├── Header.svelte
│   │   │   ├── john.svg
│   │   │   └── svelte-logo.svg
│   │   └── Loader
│   │       └── Loader.svelte
│   ├── dist
│   │   └── css
│   │       ├── style.min.css
│   │       └── style.min.css.map
│   ├── global.d.ts
│   ├── lib
│   │   ├── formats
│   │   │   └── formatString.ts
│   │   ├── helpers
│   │   │   ├── buttonText.ts
│   │   │   └── whitespacesHelper.ts
│   │   ├── interfaces
│   │   │   ├── error.interface.ts
│   │   │   ├── user.interface.ts
│   │   │   └── variables.interface.ts
│   │   ├── store
│   │   │   ├── loadingStore.ts
│   │   │   ├── notificationStore.ts
│   │   │   └── userStore.ts
│   │   └── utils
│   │       ├── constants.ts
│   │       └── requestUtils.ts
│   ├── routes
│   │   ├── accounts
│   │   │   ├── login
│   │   │   │   └── index.svelte
│   │   │   ├── register
│   │   │   │   └── index.svelte
│   │   │   └── user
│   │   │       └── [username]-[id].svelte
│   │   ├── index.svelte
│   │   └── __layout.svelte
│   └── sass
│       ├── _about.scss
│       ├── _form.scss
│       ├── _globals.scss
│       ├── _header.scss
│       ├── _home.scss
│       ├── style.scss
│       └── _variables.scss
├── static
│   ├── favicon.png
│   ├── robots.txt
│   ├── svelte-welcome.png
│   └── svelte-welcome.webp
├── svelte.config.js
└── tsconfig.json
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Accept my apologies for the incoveniences.

Now, let's get right into adding this functionality.

Update user data

It's a very common thing in web applications to allow users alter their initial data. Let's provide this feature our application's users too.

Create a .svelte file in routes/accounts/user/ directory. You are at liberty to give it any name you want. However, I'd like to make it dynamic. To make a dynamic page routing in SvelteKit, you use [](square brackets) with the dynamic field inside and then .svelte. For our purpose, we want the URL to have user's username and ID. Therefore, the name of our dynamic file will be [username]-[id].svelte. Awesome huh! SvelteKit is truly awesome.

Next, let's purpulate this newly created file with the following content:

<script context="module" lang="ts">
    import { variables } from '$lib/utils/constants';
    import { getCurrentUser } from '$lib/utils/requestUtils';
    import type { Load } from '@sveltejs/kit';
    import type { User } from '$lib/interfaces/user.interface';

    export const load: Load = async ({ fetch }) => {
        const [userRes, errs] = await getCurrentUser(
            fetch,
            `${variables.BASE_API_URI}/token/refresh/`,
            `${variables.BASE_API_URI}/user/`
        );

        const userResponse: User = userRes;

        if (errs.length > 0 && !userResponse.id) {
            return {
                status: 302,
                redirect: '/accounts/login'
            };
        }

        return {
            props: { userResponse }
        };
    };
</script>

<script lang="ts">
    import { notificationData } from '$lib/store/notificationStore';

    import { scale } from 'svelte/transition';
    import { UpdateField } from '$lib/utils/requestUtils';

    import { onMount } from 'svelte';
    import { nodeBefore } from '$lib/helpers/whitespacesHelper';
    export let userResponse: User;

    const url = `${variables.BASE_API_URI}/user/`;

    onMount(() => {
        const notifyEl = document.getElementById('notification') as HTMLElement;

        if (notifyEl && $notificationData !== '') {
            setTimeout(() => {
                notifyEl.classList.add('disappear');
                notificationData.update(() => '');
            }, 3000);
        }
    });

    let triggerUpdate = async (e: Event) => {
        const sibling = nodeBefore(<HTMLElement>e.target);
        await UpdateField(sibling.name, sibling.value, url);
    };
</script>

<div class="container" transition:scale|local={{ start: 0.7, delay: 500 }}>
    {#if userResponse.id}
        <h1>
            {userResponse.full_name ? userResponse.full_name : userResponse.username} profile
        </h1>
    {/if}

    <div class="user" transition:scale|local={{ start: 0.2 }}>
        <div class="text">
            <input
                aria-label="User's full name"
                type="text"
                placeholder="User's full name"
                name="full_name"
                value={userResponse.full_name}
            />
            <button class="save" aria-label="Save user's full name" on:click={(e) => triggerUpdate(e)} />
        </div>
    </div>
    <div class="user" transition:scale|local={{ start: 0.3 }}>
        <div class="text">
            <input
                aria-label="User's username"
                type="text"
                placeholder="User's username"
                name="username"
                value={userResponse.username}
            />
            <button class="save" aria-label="Save user's username" on:click={(e) => triggerUpdate(e)} />
        </div>
    </div>
    <div class="user" transition:scale|local={{ start: 0.4 }}>
        <div class="text">
            <input
                aria-label="User's email"
                placeholder="User's email"
                type="email"
                name="email"
                value={userResponse.email}
            />
            <button class="save" aria-label="Save user's email" on:click={(e) => triggerUpdate(e)} />
        </div>
    </div>
    <div class="user" transition:scale|local={{ start: 0.5 }}>
        <div class="text">
            <input
                aria-label="User's bio"
                placeholder="User's bio"
                type="text"
                name="bio"
                value={userResponse.bio}
            />
            <button class="save" aria-label="Save user's bio" on:click={(e) => triggerUpdate(e)} />
        </div>
    </div>
    <div class="user" transition:scale|local={{ start: 0.6 }}>
        <div class="text">
            <input
                aria-label="User's date of birth"
                type="date"
                name="birth_date"
                placeholder="User's date of birth"
                value={userResponse.birth_date}
            />
            <button
                class="save"
                aria-label="Save user's date of birth"
                on:click={(e) => triggerUpdate(e)}
            />
        </div>
    </div>
</div>
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Whoa!!! That's a lot, man! Errm... It's but let's go through it.

  • Module script section: We started the file by creating a script module. Inside it is the magical load function which does only one thing: get the current user. Were you successful at that? Yes? Put the response in userResponse variable and make it available to the rest of the program using props. No? Redirect the user to the login page. Pretty simple huh? I think it's.

  • Second script section: This section's snippets are pretty basic. The major things to note are the retrieval of the props made available by our module, and the definition of triggerUpdate asynchronous function. To retrieve and then expose props values, we only did export let userResponse: User; and that's it. What about the triggerUpdate function? Well, it is a very short function with this definition:

  let triggerUpdate = async (e: Event) => {
    const sibling = nodeBefore(<HTMLElement>e.target);
    await UpdateField(sibling.name, sibling.value, url);
  };
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It accepts an Event object, and using it, determines the value and name of the previous sibling (an input) using a custom function, named nodeBefore. Why not use (<HTMLElement>e.target).previousSibling instead? This MDN article, How whitespace is handled by HTML, CSS, and in the DOM, explained it. As a matter of fact, the snippets in $lib/helpers/whitespacesHelper.ts were ported from the JavaScript snippets made available on the article. Then, we called on UpdateField function, having this content:

  // lib -> utils -> requestUtils.ts

  ...
  export const UpdateField = async (
    fieldName: string,
    fieldValue: string,
    url: string
  ): Promise<[object, Array<CustomError>]> => {
    const userObject: UserResponse = { user: {} };
    let formData: UserResponse | any;
    if (url.includes('/user/')) {
        formData = userObject;
        formData['user'][`${fieldName}`] = fieldValue;
    } else {
        formData[`${fieldName}`] = fieldValue;
    }

    const [response, err] = await handlePostRequestsWithPermissions(fetch, url, formData, 'PATCH');
    if (err.length > 0) {
        console.log(err);
        return [{}, err];
    }
    console.log(response);
    notificationData.set(`${formatText(fieldName)} has been updated successfully.`);
    return [response, []];
  };
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This function just prepares the data to be sent to the server and then calls on the function that really sends it: handlePostRequestsWithPermissions. handlePostRequestsWithPermissions is a multipurpose or maybe generic function that can be used to make any post requests that require some permissions. Though written to work for this project, it can be modified to suit other projects' needs. It's content is:

  // lib -> utils -> requestUtils.ts

  ...
  export const handlePostRequestsWithPermissions = async (
    fetch,
    targetUrl: string,
    body: unknown,
    method = 'POST'
  ): Promise<[object, Array<CustomError>]> => {
    const res = await fetch(`${variables.BASE_API_URI}/token/refresh/`, {
        method: 'POST',
        mode: 'cors',
        headers: {
            'Content-Type': 'application/json'
        },
        body: JSON.stringify({
            refresh: `${browserGet('refreshToken')}`
        })
    });
    const accessRefresh = await res.json();
    const jres = await fetch(targetUrl, {
        method: method,
        mode: 'cors',
        headers: {
            Authorization: `Bearer ${accessRefresh.access}`,
            'Content-Type': 'application/json'
        },
        body: JSON.stringify(body)
    });

    if (method === 'PATCH') {
        if (jres.status !== 200) {
            const data = await jres.json();
            console.error(`Data: ${data}`);
            const errs = data.errors;
            console.error(errs);
            return [{}, errs];
        }
        return [jres.json(), []];
    } else if (method === 'POST') {
        if (jres.status !== 201) {
            const data = await jres.json();
            console.error(`Data: ${data}`);
            const errs = data.errors;
            console.error(errs);
            return [{}, errs];
        }
        return [jres.json(), []];
    }
  };
  ...
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It currently handles POST and PATCH requests but as said earlier, it can be extended to accommodate PUT, DELETE, and other "unsafe" HTTP verbs.

The triggerUpdate method was bound to the click event of the button element attached to each input element on the form. When you focus on the input element, a disk-like image pops up at right-most part the the input and clicking it triggers triggerUpdate which in-turn calls on updateField, and then handlePostRequestsWithPermissions.

[Heaves a sigh of relief], that's basically it! If I get less busy, I might still work on this project to make it more than just an authentication system. Contributions are also welcome. Kindly drop comments if there's anything you wanna let me know. See y'all...

Outro

Enjoyed this article, consider contacting me for a job, something worthwhile or buying a coffee ☕. You can also connect with/follow me on LinkedIn.

Top comments (5)

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ijsucceed profile image
Jeremy Ikwuje •

Considering the Load function that redirect the user incase no user is found. My question then is, do I have to always make a request to the backend api to protect pages from non authenticated users?

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sirneij profile image
John Owolabi Idogun • • Edited

Great question. You don't have to do that. A better way of implementing protected pages without having to go back to the server is to store user info in a special SvelteKit store, session. The value gets destroyed as soon as you destroy the components or the session expires.

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ijsucceed profile image
Jeremy Ikwuje •

Can you show how or point to a resource?

Thread Thread
 
sirneij profile image
John Owolabi Idogun •

Sadly, there is no much resource online for that aside the example in Real World Svelte app. But I will try to explain it here. I will assume you are using TypeScript and that my user type is like:

export interface Token {
    refresh: string;
    access: string;
}
export interface User {
    id?: string;
    email?: string;
    username?: string;
    tokens?: Token;
    full_name?: string;
}
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If this type declaration is in src/lib/types/user.interface.ts, I can then import it to app.d.ts and make the Session typed as follows:

import type { User } from '$lib/types/user.interface';
declare global {
    declare namespace App {
        interface Session {
            user: User;
        }
    }
}
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Then in your login page, you first ensure that the user is not logged in by having this load function:

<script context="module" lang="ts">
    export const load: Load = async ({ session }) => {
        if (!isEmpty(session.user)) {
            return {
                status: 302,
                redirect: '/'
            };
        }
        return {};
    };
</script>
...
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isEmpty is a function that checks whether or not an object is empty. An implementation is:

export const isEmpty = (obj) => {
    if (obj === undefined || obj === null) {
        obj = {};
    }
    return Object.keys(obj).length === 0;
};
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In the load function, we ensure that a logged in user can't re-login. In the other script tag in the login component and immediately after a user successfully logs in, you can then set the user in the session:

...
// Code that logs user in. After a successfully login attempt
$session.user = responseFromTheBackend;
...
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Since session is a store shipped with SvelteKit, we used the auto-subscription sign, $ to access and set the user properties to the response gotten from the backend after the user signs in. Which means the backend must return the user's data as declared in:

export interface User {
    id?: string;
    email?: string;
    username?: string;
    tokens?: Token;
    full_name?: string;
}
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After setting this, on every protected page, you can have a load function such as:

<script context="module" lang="ts">
    export const load: Load = async ({ session }) => {
        if (isEmpty(session.user)) {
            return {
                status: 302,
                redirect: <login_url>
            };
        }
    };
</script>
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This time, it doesn't go back to the backend to fetch user's data. Instead, it gets the user data stored in the session store and validates the requests made by the user. The session store can be imported like:

import { session } from '$app/stores';
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Hope this helps.

Thread Thread
 
ijsucceed profile image
Jeremy Ikwuje • • Edited

Yeah, thanks for taking the time. Though I don't write Typescript, but I can understand what you're trying to do.

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