Trigger AWS Lambda Functions from a React App

AWS Lambda is a serverless compute service that lets you run code without provisioning or managing servers. It can be triggered by a variety of events such as changes to data in an S3 bucket or a DynamoDB table, or by an API Gateway request. React is a JavaScript library for building user interfaces. By using React and Lambda together, you can build powerful and scalable web applications that can handle a large amount of traffic and data.

In this guide, you will learn how to call a Lambda function from a React application. This is a useful technique if you want to retrieve data from a database or perform some other server-side processing in response to an event in your React application. The guide will take you through the process of setting up a new React application, creating a function to invoke the Lambda function, and then calling that function from a React component.

Here’s a step-by-step guide on how to call a Lambda function from a React JS application:

1. Create a new React application using create-react-app or a similar tool.

2. In the root of your React application, create a new folder called lambda. Inside this folder, create a new file called lambdaFunctions.js.

3. In the lambdaFunctions.js file, import the aws-sdk library and configure it with your AWS credentials.

import AWS from 'aws-sdk';

AWS.config.update({
  region: 'us-east-1',
  accessKeyId: 'YOUR_ACCESS_KEY',
  secretAccessKey: 'YOUR_SECRET_KEY',
});

4. Create a new function in the lambdaFunctions.js file that will invoke your Lambda function. You can use the AWS.Lambda() object to call the invoke() method and pass in the name of your Lambda function and any data you want to pass to it.

const invokeLambdaFunction = (functionName, payload) => {
  const lambda = new AWS.Lambda();
  const params = {
    FunctionName: functionName,
    Payload: JSON.stringify(payload),
  };
  return lambda.invoke(params).promise();
};

5. Import the lambdaFunctions.js file in the component where you want to call the Lambda function.

6. In the component, you can call the invokeLambdaFunction function, passing in the name of your Lambda function and any data you want to pass to it. You can use the promise returned by invokeLambdaFunction to handle the response from the Lambda function.

import { invokeLambdaFunction } from './lambda/lambdaFunctions';

function MyComponent() {
  const handleClick = async () => {
    const payload = { name: 'John Doe' };
    const lambdaResponse = await invokeLambdaFunction('myLambdaFunction', payload);
    console.log(lambdaResponse);
  };

  return (
    <button onClick={handleClick}>Call Lambda Function</button>
  );
}

7. Make sure that you have proper IAM Roles and policies to allow your React App to invoke the Lambda function

This guide provides a basic setup for calling a Lambda function from a React application. You may need to adjust the code to suit your specific needs.