Module Not Found Can T Resolve Aws Amplify
AWS Amplify is a tool developed by Amazon Web Services that helps make app development easier.
It includes loads of features which allow you to quickly and easily work with other AWS services. This means you can spend more time building the features that make your app unique.
This tutorial is split into four parts:
- How to create the app with login
- How to add a database and work with the data
- How to add file storage and use those files
- How to allow users to upload their own files and data
If you want to read this article offline then you can download it here.
How to Create the App with Signup, Login and Logout
In this first section we'll be setting up a new React App with AWS Amplify to add Sign up, Login and Logout in the easiest way possible.
We need to start by creating a new React app using create-react-app. Open a terminal and run these commands. If you don't have create-react app installed then you can run npm i -g create-react-app first.
npx create-react-app amplify-react-app cd amplify-react-app With that set up we can now install Amplify and then configure it.
npm install -g @aws-amplify/cli amplify configure This will open up an AWS console tab in your browser. Make sure that you're logged into the correct account with a user that has admin permissions.
Go back to the terminal and follow the steps, adding a region and name for the user. This will then take you back the the browser where you can follow the steps to create the new user. Make sure to stay on the page where you see the key and secret!
Back in the terminal again you can follow the steps, copying the access key and secret into the terminal when asked. When you are asked if you want to add this to a profile say Yes. Create a profile that is something like serverless-amplify.
Now we can initialise the amplify setup by running amplify init. You can give the project a name and answer all the questions. Most of them should be correct already. This then takes a while to make the changes on your account.
Once done we need to add authentication to the app. We do this with amplify add auth. Select the method as default the sign in to email and then no, I am done. We can now deploy this by running amplify push. This takes a while but at the end, our src/aws-exports.js file has been created.
How to Build the React App
Now we can get onto creating the react app. Start by installing the Amplify npm packages we need.
npm install --save aws-amplify @aws-amplify/ui-react Now we can start editing the code of our app. In our src/App.js file we can remove everything in the headers and replace it with this:
<header className="App-header"> <AmplifySignOut /> <h2>My App Content</h2> </header> This is a very basic set up but you could put the main content of your site here and put the AmplifySignOut button where ever you want it to be.
We also need to add some extra imports to the top of the file:
import Amplify from 'aws-amplify'; import awsconfig from './aws-exports'; import { AmplifySignOut, withAuthenticator } from '@aws-amplify/ui-react'; Amplify.configure(awsconfig); Now the last thing that we need to do is to change the way that we export the app. Change the last line to be export default withAuthenticator(App); to add Amplify to this app.
Now when we run npm start we should get a login screen. We've not created this so it has come from Amplify itself.
If we try and log in then it will fail, as we need to sign up first. We can click create account and then enter our email and a password to sign up.
Once we've confirmed our email by submitting the code we were sent, we get onto the home page of our app. If we log out we can now log back in as expected.
How to Add a Database to our App
If you want to add data to your React app but don't want to have to build an API, then this is the section for you. We'll be having a look at how we can use AWS amplify inside our React app to allow us to access our database on the back end using GraphQL.
To start we need to go into the terminal and run:
amplify add api This will start us in a set of CLI options, asking us a few configuration questions:
What kind of API we want to use: GraphQL
The name of the API: songAPI
How we want to authenticate the API: Amazon Cognito User Pool
Advanced Settings: No, I am done
Do you have a schema: No
What kind of schema do you want: Single object with fields
After a little setup we are asked if we want to edit our new schema. We want to say yes. This opens the GraphQL schema which we're going to update to be the schema listed here.
type Song @model { id: ID! title: String! description: String! filePath: String! likes: Int! owner: String! } With our schema set up we're going to run amplify push which will compare our current amplify setup with that on our AWS account. As we've added a new API we'll have changes, so we will be asked if we want to continue with the changes.
Once we've selected Yes then we're put into another set of options.
Do we want to generate code for our GraphQL API: Yes
Which Language: JavaScript
File pattern for the new files: src/graphql/**/*.js
Generate all operations: Yes
Maximum statement depth: 2
This will now deploy all of the changes to AWS and also set up the new request files in our React app. This does take a few minutes to do.
Once that is completed we can go into our App.js file and rename it to be App.jsx. This just makes it easier to write our JSX code.
We now need to write a function in here to get the list of songs from our new database. This function calls the GraphQL API passing in the operation of listSongs. We also need to add a new state to the App component.
const [songs, setSongs] = useState([]); const fetchSongs = async () => { try { const songData = await API.graphql(graphqlOperation(listSongs)); const songList = songData.data.listSongs.items; console.log('song list', songList); setSongs(songList); } catch (error) { console.log('error on fetching songs', error); } }; We now need to add or update a few imports to our file to get this working:
import React, { useState, useEffect } from 'react'; import { listSongs } from './graphql/queries'; import Amplify, { API, graphqlOperation } from 'aws-amplify'; The listSongs is one of those functions created by amplify to help us access our data. You can see the other functions that are available in the ./graphql folder.
Now we want this function to be called once when the component renders, but not every time that it re-renders. To do this we use useEffect but make sure to add a second parameter of [] so that it only gets triggered once.
useEffect(() => { fetchSongs(); }, []); If we now start our app using npm start and then go to the app we can open the console and see a log of song list []. This means that the useEffect has called the fetchSongs which is console logging out the result, but currently there is nothing in the database.
To correct this we need to log into our AWS account and add the DynamoDB service. We should find a new table called something like Song-5gq8g8wh64w-dev. If you can't find it make sure to check other regions as well.
This currently has no data so we need to add some. For now we're going with manually creating new data in here. Under Items click Create item and then make sure the dropdown in the top left shows text. If it shows tree then just click it and change it to text. We can then make the data go into that row.
We start with the GraphQL schema, giving the row some data for each attribute. But we also need to add createdAt and updatedAt values. You can find this using the browser console.
Type new Date().toISOString() and copy the result of that. You should end up with an object like this:
{ "id": "gr4334t4tog345ht35", "title": "My First Song", "description": "A test song for our amplify app", "owner": "Sam Williams", "filePath": "", "likes": 4, "createdAt": "2020-08-13T07:01:39.176Z", "updatedAt": "2020-08-13T07:01:39.176Z" } If we save that new object then we can go back into our app and refresh the page. We should now be able to see our data in the console.log.
We can now use this data in our app to show the list of songs that we just got. Replace the existing text of song list with this set of JSX.
<div className="songList"> {songs.map((song, idx) => { return ( <Paper variant="outlined" elevation={2} key={`song${idx}`}> <div className="songCard"> <IconButton aria-label="play"> <PlayArrowIcon /> </IconButton> <div> <div className="songTitle">{song.title}</div> <div className="songOwner">{song.owner}</div> </div> <div> <IconButton aria-label="like"> <FavoriteIcon /> </IconButton> {song.likes} </div> <div className="songDescription">{song.description}</div> </div> </Paper> ); })} </div> This code is mapping over each song in the list and rendering a new Paper for them with all the details we need.
We're using the MaterialUI library to help make this look nice for us so we need to make sure to run npm install --save @material-ui/core @material-ui/icons to install those packages and then add them to the imports at the top of the file too:
import { Paper, IconButton } from '@material-ui/core'; import PlayArrowIcon from '@material-ui/icons/PlayArrow'; import FavoriteIcon from '@material-ui/icons/Favorite'; With this, if we save and reload our app we now get this:
Whilst this is ok, we can update the CSS to make it look far better. Open up your App.css file and change it to this:
.App { text-align: center; } .App-logo { height: 10vmin; pointer-events: none; } .App-header { background-color: #282c34; min-height: 5vh; display: flex; align-items: center; justify-content: space-around; font-size: calc(10px + 2vmin); color: white; } .App-link { color: #61dafb; } .songList { display: flex; flex-direction: column; } .songCard { display: flex; justify-content: space-around; padding: 5px; } .songTitle { font-weight: bold; } Now we get it looking like this - much better.
Now we've got one item in the database so we only get one record. If we go back into Dynamo and create a new item or duplicate the existing one then we can see how multiple songs look. You can duplicate an item by clicking the checkbox to its left
Now that we can get the data, what about updating that info? For this we are going to add the ability to like a song. To start this we can add an onClick function to the icon button that we have for the likes.
<IconButton aria-label="like" onClick={() => addLike(idx)}> <FavoriteIcon /> </IconButton> You may have realised that there is this idx property that we haven't see before. That is short for index.
Where we do the songs.map we can update it slightly to get the position of each item in the list. We can also use this idx to add a key to the top level Paper in that map to remove an errors we get from React.
{songs.map((song, idx) => { return ( <Paper variant="outlined" elevation={2} key={`song${idx}`}> ... </Paper> )} )} With the new index and the onClick function call, we now need to make the addLike function.
This function needs to take the index of the song to find the correct song and update the number of likes. It then removes some fields that can't be passed into the updateSong operation before calling that operation.
const addLike = async idx => { try { const song = songs[idx]; song.likes = song.likes + 1; delete song.createdAt; delete song.updatedAt; const songData = await API.graphql(graphqlOperation(updateSong, { input: song })); const songList = [...songs]; songList[idx] = songData.data.updateSong; setSongs(songList); } catch (error) { console.log('error on adding Like to song', error); } }; Once the song has been updated in the database, we need to get that update back into our state. We need to clone the existing songs using const songList = [...songs].
If we just mutate the original list of songs then React wouldn't have re-rendered the page. With that new song list we call setSongs to update our state and we're done with the function.
We just need to add one more import to the top of the file which we get from the mutators that Amplify created:
import { updateSong } from './graphql/mutations'; Now when we click on the like button on a song, it is updated in state and in the database.
How to Add File Storage
Now that we have the song data stored in Dynamo, we want to store the actual MP3 data somewhere. We'll be storing the songs in S3 and accessing them using Amplify.
How to Add Play/Pause Functionality
To get started we're going to add a way to play and pause each of the songs. For now, this will just change the play button to a pause button.
Later we'll be using the Amplify Storage methods to get our MP3 file from S3 and play it directly in our app.
We're going to add a new function to the App component called toggleSong.
const toggleSong = async idx => { if (songPlaying === idx) { setSongPlaying(''); return; } setSongPlaying(idx); return } To get this working we also need to add a new state variable to the app. This will be used to store the index of the song that is currently playing.
const [songPlaying, setSongPlaying] = useState(''); With this set up we need to make a change to the JSX code to use our new function and variables.
Find the first button in the songCard div. We're going to be adding an onClick which calls our new function. We're also going to use a ternary equation to say that if the song that is playing is this song, show a pause icon instead of a play icon.
<IconButton aria-label="play" onClick={() => toggleSong(idx)}> {songPlaying === idx ? <PauseIcon /> : <PlayArrowIcon />} </IconButton> We'll just need to import the PauseIcon at the top of the file and we'll be ready.
import PauseIcon from '@material-ui/icons/Pause'; 
How to Add the Storage to Amplify
Next, we need to use the Amplify CLI to add the storage to our app. We can start by going into our terminal and running amplify add storage. This will open a CLI where we need to select the following options.
Please select your service = Content (images, audio, video, etc.)
Friendly name for your resource = songStorage
Bucket name = song-storage
Who should have access = Auth Users Only
What access do those users have = Read and Create/Update
Do you want a Lambda trigger? = No
With that all configured we need to deploy it. We can start that with amplify push which will take a little bit of time to work out what we've changed in our amplify application. You'll then get a little display of all of the resources we have in Amplify.
The only change is the creation of our new songStorage resource. We can select Yes to continuing and then it will create our S3 bucket for us.
How to Access the S3 File through the Amplify Storage methods
Once the deployment has finished we can start using that to access our songs. Back in our toggleSong function we are going to add some extra logic.
const toggleSong = async idx => { if (songPlaying === idx) { setSongPlaying(''); return; } const songFilePath = songs[idx].filePath; try { const fileAccessURL = await Storage.get(songFilePath, { expires: 60 }); console.log('access url', fileAccessURL); setSongPlaying(idx); setAudioURL(fileAccessURL); return; } catch (error) { console.error('error accessing the file from s3', error); setAudioURL(''); setSongPlaying(''); } }; This is getting the file path from the song data (that was stored in Dynamo) and then using Storage.get(songFilePath, { expires: 60 }); to get an access URL for the file.
The on the end is saying that the URL returned is only going to work for 60 seconds. After that you won't be able to access the file with it. This is a useful security measure so people can't share the URL to others who shouldn't have access to the files.{ expires: 60 }
Once we have the file, we're also setting that in a new state variable using setAudioURL. At the top of our App we need to add this extra state.
const [audioURL, setAudioURL] = useState(''); Save this and go back into our app. If we press the play button and open the console we'll see the URL being logged out. This is what we're going to use to play the song.
How to Upload Our Songs
We're now getting to the point where we need some songs to play. If we go into our AWS account and search for S3 and then search for song , we should find our new S3 bucket.
In there we need to create a new folder called public. This is because the files will be public to everyone who has signed into the app. There are other ways of storing data which are private and only viewable by specific people.
Inside that folder we need to upload two songs. I have two copyright free songs that I uploaded called epic.mp3 and tomorrow.mp3. Once they have been uploaded we need to update our Dynamo data to point at those songs.
In Dynamo we can find our Songs-(lots of random charachters) table. Under Items we should have two records. Open up the first one and change the filePath to tomorrow.mp3 and the name to Tomorrow.
Save that and open the second song, changing that to "filePath": "epic.mp3" and "name": "Epic" , saving that file too.
If you used your own songs then just make sure the filePath matches the file name of your songs.
We can now go back into our app, refresh the page, and press play on one of the songs. If we look in our console and copy the URL we're given we can paste that into a browser and our song should start playing.
How to Add a Media Player to Our App
Now we want to be able to actually play our song from within our app. To do this we're going to use a library called react-player. We need to first install it with npm install --save react-player.
In our app we can then import it at the top of the file.
import ReactPlayer from 'react-player'; If we find our <div className ="songCard">, we want to add our player after that component. In the same way we showed the play/pause icons, we're going to show or hide this player based on which song is playing.
<div className="songCard"> .. .. </div> {songPlaying === idx ? ( <div className="ourAudioPlayer"> <ReactPlayer url={audioURL} controls playing height="50px" onPause={() => toggleSong(idx)} /> </div> ) : null} The ReactPlayer takes a few parameters. The url is just the file URL to play, which is the one we get from Amplify Storage. controls allows the user to change the volume or pause the song. playing means the song starts playing as soon as it's loaded and onPause is a listener so we can have the inbuilt pause button work the same as our pause button.
With this all done we can save everything again and open our App. In there if we press play on one of the songs, we should see a player appear and the song will be playing.
How to Enable User Uploads
Now we have an app which allows users to view all of the songs and play them from S3. To build upon that we want to allow our users to upload their own songs to the platform.
We first need to create a way to add a song and input some information. We start by creating an Add button.
{ showAddSong ? <AddSong /> : <IconButton> <AddIcon /> </IconButton> } We then also need to add the AddIcon to our imports.
import AddIcon from '@material-ui/icons/Add'; Now we can move onto creating the new AddSong component. We can create this at the bottom of our App.jsx file.
const AddSong = () => { return ( <div className="newSong"> <TextField label="Title" /> <TextField label="Artist" /> <TextField label="Description" /> </div> ) } We also need to add TextField to our imports from material UI.
import { Paper, IconButton, TextField } from '@material-ui/core'; The next thing to do is add the ability to open our new component by controlling the showAddSong variable. We need to create a new state declaration next to the others.
const [showAddSong, setShowAddNewSong] = useState(false); We can now update our new AddIcon button to set showAddSong to true.
<IconButton onClick={() => setShowAddNewSong(true)}> <AddIcon /> </IconButton> To change it back, we can add a parameter to our AddSong component called onUpload. When this gets called we will reset the showAddSong to false.
<AddSong onUpload={() => { setShowAddNewSong(false); }} /> We then need to update our component to work with that new parameter and a button to "upload" the new song. That button calls a function in the component where we will add the ability to upload the data, but for now we will just call the onUpload function.
const AddSong = ({ onUpload }) => { const uploadSong = async () => { //Upload the song onUpload(); }; return ( <div className="newSong"> <TextField label="Title" /> <TextField label="Artist" /> <TextField label="Description" /> <IconButton onClick={uploadSong}> <PublishIcon /> </IconButton> </div> ); }; And now we add the PublishIcon to our imports and we're ready to test this out.
import PublishIcon from '@material-ui/icons/Publish'; When we start up the app and log in we now get a plus icon. By clicking that we can enter some details for the song and click upload.
How to Update AddSong
Now we want to be able to store and access the data that a user enters into the fields when adding a song.
const AddSong = ({ onUpload }) => { const [songData, setSongData] = useState({}); const uploadSong = async () => { //Upload the song console.log('songData', songData); const { title, description, owner } = songData; onUpload(); }; return ( <div className="newSong"> <TextField label="Title" value={songData.title} onChange={e => setSongData({ ...songData, title: e.target.value })} /> <TextField label="Artist" value={songData.owner} onChange={e => setSongData({ ...songData, owner: e.target.value })} /> <TextField label="Description" value={songData.description} onChange={e => setSongData({ ...songData, description: e.target.value })} /> <IconButton onClick={uploadSong}> <PublishIcon /> </IconButton> </div> ); }; We've also had to change all of the TextFields to be controlled, passing in a value from out state and providing an onChange too. If we save this and try entering some details before uploading we should see a console.log of the details in our chrome console.
Next we need to add the ability to actually upload the song. For this we'll be using the default html input with a type of file. Add this to the JSX just before the upload icon button.
<input type="file" accept="audio/mp3" onChange={e => setMp3Data(e.target.files[0])} /> As you may have noticed we are calling setMp3Data on change. This is some more state in the AddSong component.
const [mp3Data, setMp3Data] = useState(); Now that we have all of the data that we need, we can start by uploading the song to S3 and then the data to our database.
To upload the song we're going to use the Amplify Storage class again. The fileName is going to be a UUID so we also need to run npm install --save uuid in our terminal and then import it at the top of our file import { v4 as uuid } from 'uuid';. We then pass in the mp3Data and a contentType and we get back an object with a key.
const { key } = await Storage.put(`${uuid()}.mp3`, mp3Data, { contentType: 'audio/mp3' }); Now that we have the key we can create the record for the song in the database. As there may be multiple songs with the same name, we'll use an UUID as the ID again.
const createSongInput = { id: uuid(), title, description, owner, filePath: key, like: 0, }; await API.graphql(graphqlOperation(createSong, { input: createSongInput })); To get this to work we need to import the createSong mutator that was created when we created the dynamo storage with Amplify.
import { updateSong, createSong } from './graphql/mutations'; The last thing that we need to do is make the app re-get the data from the database once we've finished uploading it. We can do this by adding a fetchSongs call as part of the onUpload function.
<AddSong onUpload={() => { setShowAddNewSong(false); fetchSongs(); }} /> Now when we reload the page, we can click to add a new song, input the details, select our new song, upload it and then play it back from the app.
That's all, folks!
If you've liked this article (and accompanying videos) and want to help me out, then the best thing you can do is to subscribe to my Youtube Channel. I create weekly videos on AWS and Serverless to help you become a better developer. Subscribe Here
Learn to code for free. freeCodeCamp's open source curriculum has helped more than 40,000 people get jobs as developers. Get started
Module Not Found Can T Resolve Aws Amplify
Source: https://www.freecodecamp.org/news/ultimate-guide-to-aws-amplify-and-reacxt/