Deploy a Web App on AWS Amplify

Tutorial

Introduction

Create Amplify Project

Initialize the Backend

Build the Frontend

Deploy the App

Clean up Resources

Task 3: Build the Frontend

In this task, you will create an app frontend and connect it to the cloud backend you have already built.

Introduction

In this task, you will learn how to use the Amplify UI component library to scaffold out an entire user authentication flow, allow users to sign up, sign in, and reset their password with just few lines of code. Additionally, you will build an app frontend that allows users to create, update, and delete their expenses.

What you will accomplish

Install the Amplify client libraries
Configure your React app to include authentication, data, and storage for the expenses feature

Implementation

Time to Complete

5 minutes

Get help

Troubleshooting Amplify

Step 1: Install the Amplify libraries
You will need two Amplify libraries for your project. The main aws-amplify library contains all of the client-side APIs for connecting our app's frontend to our backend, and the @aws-amplify/ui-react library contains framework-specific UI components.
1. Open a new terminal window, navigate to your projects root folder (expensetracker), and run the following command to install these libraries in the root of the project.

npm install aws-amplify @aws-amplify/ui-react

Step 2: Style the App UI

1. On your local machine, navigate to the expensetracker/src/index.css file, and update it with the following code to set the style of the UI. Then, save the file.

:root {
  font-family: Inter, system-ui, Avenir, Helvetica, Arial, sans-serif;
  line-height: 1.5;
  font-weight: 400;

  color: rgba(255, 255, 255, 0.87);

  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;

  max-width: 1280px;
  margin: 0 auto;
  padding: 2rem;

}

.card {
  padding: 2em;
}

.read-the-docs {
  color: #888;
}

.box:nth-child(3n + 1) {
  grid-column: 1;
}
.box:nth-child(3n + 2) {
  grid-column: 2;
}
.box:nth-child(3n + 3) {
  grid-column: 3;
}

Step 3: Implement the UI flow for Expenses feature

In this step, you will update the src/App.jsx file to configure the Amplify library with the client configuration file (amplify_outputs.json). Then, it will generate a data client using the generateClient() function.

The code uses the Amplify Authenticator component to scaffold out an entire user authentication flow allowing users to sign up, sign in, reset their password, and confirm sign-in for multifactor authentication (MFA).

Additionally, the code contains the following:

A code to use a real-time observeQuery to subscribe to a live feed of the user’s expenses data.
createExpense - Get the data from the form and use the data client to create a new expense.
deleteExpense - Use the data client to delete the selected expense.

1. On your local machine, navigate to the expensetracker/src/app.jsx file, and update it with the following code. Then, save the file.

import { useState, useEffect } from "react";
import {
  Authenticator,
  Button,
  Text,
  TextField,
  Heading,
  Flex,
  View,
  Grid,
  Divider,
} from "@aws-amplify/ui-react";
import { Amplify } from "aws-amplify";
import "@aws-amplify/ui-react/styles.css";
import { generateClient } from "aws-amplify/data";
import outputs from "../amplify_outputs.json";
/**
 * @type {import('aws-amplify/data').Client<import('../amplify/data/resource').Schema>}
 */

Amplify.configure(outputs);
const client = generateClient({
  authMode: "userPool",
});

export default function App() {
  const [expenses, setExpenses] = useState([]);

  useEffect(() => {
    client.models.Expense.observeQuery().subscribe({
      next: (data) => setExpenses([...data.items]),
    });
  }, []);

  async function createExpense(event) {
    event.preventDefault();
    const form = new FormData(event.target);

    await client.models.Expense.create({
      name: form.get("name"),
      amount: form.get("amount"),
    });

    event.target.reset();
  }

  async function deleteExpense({ id }) {
    const toBeDeletedExpense = {
      id,
    };

    await client.models.Expense.delete(toBeDeletedExpense);
  }

  return (
    <Authenticator>
      {({ signOut }) => (
        <Flex
          className="App"
          justifyContent="center"
          alignItems="center"
          direction="column"
          width="70%"
          margin="0 auto"
        >
          <Heading level={1}>Expense Tracker</Heading>
          <View as="form" margin="3rem 0" onSubmit={createExpense}>
            <Flex
              direction="column"
              justifyContent="center"
              gap="2rem"
              padding="2rem"
            >
              <TextField
                name="name"
                placeholder="Expense Name"
                label="Expense Name"
                labelHidden
                variation="quiet"
                required
              />
              <TextField
                name="amount"
                placeholder="Expense Amount"
                label="Expense Amount"
                type="float"
                labelHidden
                variation="quiet"
                required
              />

              <Button type="submit" variation="primary">
                Create Expense
              </Button>
            </Flex>
          </View>
          <Divider />
          <Heading level={2}>Expenses</Heading>
          <Grid
            margin="3rem 0"
            autoFlow="column"
            justifyContent="center"
            gap="2rem"
            alignContent="center"
          >
            {expenses.map((expense) => (
              <Flex
                key={expense.id || expense.name}
                direction="column"
                justifyContent="center"
                alignItems="center"
                gap="2rem"
                border="1px solid #ccc"
                padding="2rem"
                borderRadius="5%"
                className="box"
              >
                <View>
                  <Heading level="3">{expense.name}</Heading>
                </View>
                <Text fontStyle="italic">${expense.amount}</Text>

                <Button
                  variation="destructive"
                  onClick={() => deleteExpense(expense)}
                >
                  Delete note
                </Button>
              </Flex>
            ))}
          </Grid>
          <Button onClick={signOut}>Sign Out</Button>
        </Flex>
      )}
    </Authenticator>
  );
}

2. Open a new terminal window, navigate to your projects root folder (expensetracker), and run the following command to launch the app:

npm run dev

3. Select the Local host link to open the Vite + React application.

4. Choose the Create Account tab, and use the authentication flow to create a new user by entering your email address and a password. Then, choose Create Account.