Create a personalized link generator with Cloudinary + Auth0
Tags: cloudinary, hackjamstack, auth0, jamstack
Published: 2021-10-17 12:12:22

---
title: Create a personalized link generator with Cloudinary + Auth0
published: true
description: 
tags: #cloudinary #hackjamstack #auth0 #jamstack
cover_image: https://dev-to-uploads.s3.amazonaws.com/uploads/articles/y5z490135dns8omoj15n.png
---

Shared Links or Link sharing are specially created link to conveniently share large files that you wouldn’t be able to send via email or mobile devices. They serve as mediums that point to your files or contents stored in the cloud.

In this post, we will discuss how to build a personalized and secure link sharing application using [Cloudinary](https://cloudinary.com/), [Auth0](https://auth0.com/), and [Next.js](https://nextjs.org/). At the end of this tutorial, we would have learnt how to upload files to Cloudinary, get sharable links, share using a device clipboard, and secure the web application using Auth0.

By way of introduction, Cloudinary is a platform on which you can quickly and easily upload, store, manage, transform, and deliver images and videos for websites and apps. The platform also offers a vast collection of SDKs for frontend frameworks and libraries. 

Auth0 is a platform that offers systems to rapidly integrate authentication and authorization for web, mobile, and legacy applications.

Next.js is a React-based front-end development framework that enables functionalities like server-side rendering, static site generation, file-system routing (with no need to manually configure `react-router-dom`), and API endpoints for backend features.

## Source code

You can find the source code of this project [here](https://github.com/Mr-Malomz/link_generator).

# Prerequisites

The next steps in this post require JavaScript and React.js experience. Experience with Next.js isn’t a requirement, but it’s nice to have.

We also need the following:

- A [Cloudinary account](https://cloudinary.com/) for file hosting. [**Signup**](https://cloudinary.com/users/register/free) **is completely free**.
- An [Auth0 account](https://auth0.com/) for authentication. [**Signup**](https://auth0.com/signup?place=header&type=button&text=sign%20up) **is completely free**.
## Getting Started

We need to create a Next.js starter project by navigating to the desired directory and running the command below in our terminal


    npx create-next-app link_generator && cd link_generator

This command creates a Next.js project called `link_generator` and navigates into the project directory.

We proceed to install the required dependencies with:


    npm install react-helmet @auth0/nextjs-auth0

`react-helmet` is a [library](https://github.com/nfl/react-helmet) that takes plain HTML tags and outputs plain HTML tags. It will help us avoid the `Reference error: Window is not Defined` error when using client-side only packages in Next.js.

`@auth0/nextjs-auth0` is a [library](https://github.com/auth0/nextjs-auth0) for implementing user authentication in Next.js applications.

# File upload and link sharing with Cloudinary

With the project dependencies installed, we can leverage Next.js [CSS Module](https://github.com/css-modules/css-modules) support to style our page by replacing the content in `Home.module.css` in the `styles` folder with the gist below:

**Home.module.css**

{% gist https://gist.github.com/Mr-Malomz/65b6d831172253d348a16de2c8eadf9a %}

With that done, we can update  `index.js` file in the `pages` folder by importing the styles created and configure Cloudinary Upload Widget to upload files to Cloudinary. We also include states to handle link generation and copying.

```javascript
    import { useState } from 'react';
    import { Helmet } from 'react-helmet';
    import styles from '../styles/Home.module.css';
    
    export default function Home() {
      const [url, setURL] = useState(null);
      const [copy, setCopy] = useState('Copy File');
    
      const openWidget = () => {
        setURL(null);
        window.cloudinary
          .createUploadWidget(
            {
              cloudName: 'dtgbzmpca',
              uploadPreset: 'tca2j0ee',
            },
            (error, result) => {
              if (!error && result && result.event === 'success') {
                setURL(result.info.url);
              }
            }
          )
          .open();
      };
    
      return (
        <div>
          <Helmet>
            <script src='https://upload-widget.cloudinary.com/global/all.js' />
          </Helmet>
          <main className={styles.files}>
            {/* remaining JSX comes here */}
          </main>
        </div>
      );
    }
```

The Cloudinary Upload Widget also configures `cloudName`, `uploadPreset`, use the callback function to check for error, and update the URL based on the returned result. The `cloudname` is the name of our Cloudinary account while  `uploadPreset` is a parameter that enables us to centrally define a set of asset upload options instead of specifying them in each upload call. Finally, we used `react-helmet` to add Cloudinary Upload Widget CDN to the application.



![Shaded portions are where your cloud name is located in Cloudinary](https://paper-attachments.dropbox.com/s_4BCCCE95ACE9B0C1081840B08C278ED838CD7BEFE9CA8C7C882D08A88A918EB2_1620114874519_cloudname.png)


To create a new upload preset, click on the **Settings** Icon, select the **Upload** tab, navigate to the **Upload presets** section, click on the **Add Upload preset**.

![select preset](https://paper-attachments.dropbox.com/s_4BCCCE95ACE9B0C1081840B08C278ED838CD7BEFE9CA8C7C882D08A88A918EB2_1620116773149_Screenshot+2021-05-04+at+01.49.21.png)




![copy preset name, change to Unsigned and save](https://paper-attachments.dropbox.com/s_4BCCCE95ACE9B0C1081840B08C278ED838CD7BEFE9CA8C7C882D08A88A918EB2_1620117224843_Screenshot+2021-05-04+at+01.50.21.png)



Find out more about Cloudinary Upload Widget [here](https://cloudinary.com/documentation/upload_widget).

Next, we need to include our markup for upload and conditionally display returned link.

```javascript
    //imports here
    
    export default function Home() {
      //states here
    
      const openWidget = () => {
        //upload widget code
      };
    
      return (
        <div>
          <Helmet>
            <script src='https://upload-widget.cloudinary.com/global/all.js' />
          </Helmet>
          <main className={styles.files}>
            <header className={styles.header}>
              <a className={styles.logout}>
                Log Out
              </a>
            </header>
            <div className={styles.container}>
              <div className={styles.buttonwrapper}>
                <button className={styles.button} onClick={() => openWidget()}>
                  Upload file and Generate Link
                </button>
              </div>
              {url && (
                <div className={styles.formwrapper}>
                  <h5>Shareable link</h5>
                  <input disabled value={url} className={styles.input} />
                  <button className={styles.copy}>
                    {copy}
                  </button>
                </div>
              )}
            </div>
          </main>
        </div>
      );
    }
```

Next, we need to create a function using the [Clipboard API](https://developer.mozilla.org/en-US/docs/Web/API/Clipboard/writeText) to copy the returned URL on our device clipboard.

```javascript
    //imports here
    
    export default function Home() {
      //state here
    
      const openWidget = () => {
        //upload widget code
      };
    
      //add 
      const handleCopyToClip = () => {
        navigator.clipboard
          .writeText(url)
          .then(() => setCopy('Copied!'))
          .catch((err) => console.log('error copying to clipboard', err));
      };
    
      return (
        <div>
          <Helmet>
            <script src='https://upload-widget.cloudinary.com/global/all.js' />
          </Helmet>
          <main className={styles.files}>
            {/* header goes here */}  
            <div className={styles.container}>
              <div className={styles.buttonwrapper}>
                {/* button upload here */}  
              </div>
              {url && (
                <div className={styles.formwrapper}>
                  <h5>Shareable link</h5>
                  <input disabled value={url} className={styles.input} />
                  <button className={styles.copy} onClick={handleCopyToClip}>{/* modify this*/}
                    {copy}
                  </button>
                </div>
              )}
            </div>
          </main>
        </div>
      );
    }
```

Finally, we can start a development server and test our application:


    npm run dev


![upload button](https://paper-attachments.dropbox.com/s_43DDC2BE4B2CB1C626BCF14C8F63072226DAE7B9BE70D279E2293DF4CDDF0ABE_1633511818418_Screenshot+2021-10-06+at+10.15.12.png)
![select a file](https://paper-attachments.dropbox.com/s_43DDC2BE4B2CB1C626BCF14C8F63072226DAE7B9BE70D279E2293DF4CDDF0ABE_1633511818469_Screenshot+2021-10-06+at+10.15.30.png)
![copy link](https://paper-attachments.dropbox.com/s_43DDC2BE4B2CB1C626BCF14C8F63072226DAE7B9BE70D279E2293DF4CDDF0ABE_1633511818512_Screenshot+2021-10-06+at+10.16.19.png)

# Adding Authentication with Auth0
## Setup a Developer Account

To get started, we need to log into our [Auth0](https://auth0.com/auth/login) dashboard. Click on **Applications**

![Auth0 Dashboard](https://paper-attachments.dropbox.com/s_39889F3A941E007B2BE724DE6F2C4C4FFE6C2B007CCCDB3B36F915067C40E3D1_1633445331548_Screenshot+2021-10-05+at+15.44.55.png)


In the application page, click on the **Create Application** button, input application name `auth0Cloudinary` in our case, select **Regular Web Application** as the application type and **Create**

![Creating a new app](https://paper-attachments.dropbox.com/s_39889F3A941E007B2BE724DE6F2C4C4FFE6C2B007CCCDB3B36F915067C40E3D1_1633446208392_Screenshot+2021-10-05+at+15.50.45.png)


Click on the **Settings** tab and copy the **Domain,** **Client ID,** and **Client Secret**.

![copy credentials](https://paper-attachments.dropbox.com/s_39889F3A941E007B2BE724DE6F2C4C4FFE6C2B007CCCDB3B36F915067C40E3D1_1633446417723_Screenshot+2021-10-05+at+16.04.21.png)


Then scroll down to the **Applications URIs** section and fill in the details below for **Allowed Callback URLs** and **Allowed Logout URLs,** respectively.

- Allowed Callback URLs
    - `http://localhost:3000/api/auth/callback`
- Allowed Logout URLs
    - `http://localhost:3000/`
![URIs](https://paper-attachments.dropbox.com/s_39889F3A941E007B2BE724DE6F2C4C4FFE6C2B007CCCDB3B36F915067C40E3D1_1633447038602_Screenshot+2021-10-05+at+16.12.18.png)


Then scroll down to the bottom of the page and click on the **Save Changes** button.

## Integrating Auth0 with Next.js

To integrate Auth0 in our application, we need to create an `.env.local` file in our root directory and fill in the required parameters(**Domain, Client ID and Client Secret**) as shown below:

    AUTH0_SECRET='LONG_RANDOM_VALUE'
    AUTH0_BASE_URL='http://localhost:3000'
    AUTH0_ISSUER_BASE_URL='https://YOUR_AUTH0_DOMAIN.auth0.com'
    AUTH0_CLIENT_ID='YOUR_AUTH0_CLIENT_ID'
    AUTH0_CLIENT_SECRET='YOUR_AUTH0_CLIENT_SECRET'

We can run the snippet below on our terminal to generate a random secret for the `AUTH0_SECRET`

    node -e "console.log(crypto.randomBytes(32).toString('hex'))"

Next, we need to create a dynamic route file for our APIs. We need to navigate to the `pages` folder, inside this folder, navigate to the `api` folder, in the folder, create an `auth` folder, and inside this folder, create an `[…auth0].js` file and add the snippet below:

```javascript
    import { handleAuth } from '@auth0/nextjs-auth0';
    export default handleAuth();
```

The `handleAuth()` function will generate APIs for:

- Login
    - `/api/auth/login`
- Logout
    - `/api/auth/logout`
- Fetch user data
    - `/api/auth/me`
- Redirect user on successful login.
    - `/api/auth/callback`

Next, we need to update `_app.js` file inside the `pages` folder as shown below: 

```javascript
    import { UserProvider } from '@auth0/nextjs-auth0';
    export default function App({ Component, pageProps }) {
      return (
        <UserProvider>
          <Component {...pageProps} />
        </UserProvider>
      );
    }
```

Finally, we need to update `index.js` as shown below

```javascript
    //other imports here
    import { withPageAuthRequired } from '@auth0/nextjs-auth0';
    
    export default function Home({ user }) { //update this with destructure props
      //state goes here
    
      //functions goes here
      
      return (
        <div>
          <Helmet>
            <script src='https://upload-widget.cloudinary.com/global/all.js' />
          </Helmet>
          <main className={styles.files}>
            <header className={styles.header}>
              <a href='/api/auth/logout' className={styles.logout}> {/* add href to this*/}
                Log Out
              </a>
            </header>
            <p className={styles.name}>Hi {user.name}</p> {/*add this*/}
            {/*remaining code snippet goes here*/}
          </main>
        </div>
      );
    }
    export const getServerSideProps = withPageAuthRequired({
      returnTo: '/',
    });
 ```   

In the snippet above, we imported `withPageAuthRequired` and also modified the `log out` link. We used Next.js inbuilt method `getServerSideProps` to call the `withPageAuthRequired` method, specified the URL to redirect to after login, accessed the `user` props it returned and then displayed the user’s name.

**Complete index.js**

{% gist https://gist.github.com/Mr-Malomz/55d91809bdf6f071734a513f1fa8cd4f %}


# Conclusion

This post discussed how to build and secure an application that supports file upload to Cloudinary, get sharable links, and share using the device clipboard.

You may find these resources useful:

- [Cloudinary upload presets](https://cloudinary.com/documentation/upload_presets)
- [Cloudinary upload widget](https://cloudinary.com/documentation/upload_widget)
- [Next.js Auth0 library](https://github.com/auth0/nextjs-auth0)
- [Browser clipboard](https://developer.mozilla.org/en-US/docs/Web/API/Clipboard/writeText)

Content created for the [Hackmamba](https://content.hackmamba.io/) Jamstack Content Hackathon.