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writeLambdaFunction.js

writeLambdaFunction.js demonstrates how to write a Lambda function code

/** * Copyright 2010-2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. * * This file is licensed under the Apache License, Version 2.0 (the "License"). * You may not use this file except in compliance with the License. A copy of * the License is located at * * http://aws.amazon.com/apache2.0/ * * This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR * CONDITIONS OF ANY KIND, either express or implied. See the License for the * specific language governing permissions and limitations under the License. * */ // ABOUT THIS NODE.JS SAMPLE: This sample is part of the SDK for JavaScript Developer Guide topic at // https://docs.aws.amazon.com/sdk-for-javascript/v2/developer-guide/nodejs-write-lambda-function-example-full.html // NOTE: // Supporting topics for the above-mentioned topic also contain important information about the role policy when creating the IAM role. // Configuring the AWS SDK var AWS = require('aws-sdk'); AWS.config.update({region: 'REGION'}); exports.handler = (event, context, callback) => { const URL_BASE = "S3_BUCKET_URL"; // Define the object that will hold the data values returned var slotResults = { 'isWinner' : false, 'leftWheelImage' : {'file' : {S: ''}}, 'middleWheelImage' : {'file' : {S: ''}}, 'rightWheelImage' : {'file' : {S: ''}} }; // define parameters JSON for retrieving slot pull data from the database var thisPullParams = { Key : {'slotPosition' : {N: ''}}, TableName: 'slotWheels', ProjectionExpression: 'imageFile' }; // create DynamoDB service object var request = new AWS.DynamoDB({region: 'REGION', apiVersion: '2012-08-10'}); // set a random number 0-9 for the slot position thisPullParams.Key.slotPosition.N = Math.floor(Math.random()*10).toString(); // call DynamoDB to retrieve the image to use for the Left slot result var myLeftPromise = request.getItem(thisPullParams).promise().then(function(data) {return URL_BASE + data.Item.imageFile.S}); // set a random number 0-9 for the slot position thisPullParams.Key.slotPosition.N = Math.floor(Math.random()*10).toString(); // call DynamoDB to retrieve the image to use for the Left slot result var myMiddlePromise = request.getItem(thisPullParams).promise().then(function(data) {return URL_BASE + data.Item.imageFile.S}); // set a random number 0-9 for the slot position thisPullParams.Key.slotPosition.N = Math.floor(Math.random()*10).toString(); // call DynamoDB to retrieve the image to use for the Left slot result var myRightPromise = request.getItem(thisPullParams).promise().then(function(data) {return URL_BASE + data.Item.imageFile.S}); Promise.all([myLeftPromise, myMiddlePromise, myRightPromise]).then(function(values) { slotResults.leftWheelImage.file.S = values[0]; slotResults.middleWheelImage.file.S = values[1]; slotResults.rightWheelImage.file.S = values[2]; // if all three values are identical, the spin is a winner if ((values[0] === values[1]) && (values[0] === values[2])) { slotResults.isWinner = true; } // return the JSON result to the caller of the Lambda function callback(null, slotResults); }); };

Sample Details

Service: lambda

Last tested:

Author: AWS_JSDG

Type: full-example

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