CRUDController.js
For the full content of this gist, refer to https://gist.github.com/CodingAbdullah/5f00dcbced6a02d96a03026410660519
McMaster. Software Engineer with a keen interest in blockchain and web3.
require('dotenv').config({ path: '../.env' });
const dynamoDB = require('../AWS/dynamoDBInstance');
const bcrypt = require('bcryptjs');
exports.insertUser = (req, res) => {
const { firstName, lastName, email, password } = JSON.parse(req.body.body);
// Setting request parameters for verification
let requestParam = {
TableName: 'User',
Key: {
'emailAddress' : { 'S' : email }
}
}
// Check database if User already exists
dynamoDB.getItem(requestParam, (err, data) => {
if (err) {
res.status(400).json({
message: "Could not query database"
});
}
else {
// If response object is empty, no user entry consists of that email, proceed to insert
if (Object.keys(data).length === 0){
// Generate salt for password
bcrypt.genSalt(10, (err, salt) => {
if (err) {
res.status(400).json({
message: "Could not generate salt"
});
}
else {
// Generate hash using salt for password
bcrypt.hash(password, salt, (err, hashedPassword) => {
if (err) {
res.status(400).json({
message: "Could not hash password"
});
}
else {
// Define what needs to be inserted into DynamoDB table with hashed password
let insertObjectParam = {
TableName: 'User',
Item: {
'emailAddress': { 'S' : email },
'firstName': { 'S' : firstName },
'lastName' : { 'S' : lastName },
'password' : { 'S' : hashedPassword },
'dateCreated' : { 'S' : new Date().toISOString() },
'dateUpdated' : { 'S' : new Date().toISOString() }
}
}
// Insert object using the PutItem() function
dynamoDB.putItem(insertObjectParam, (err, data) => {
if (err) {
res.status(400).json({
message: "Could not insert User into database"
});
}
else {
res.status(200).json({
message: "User successfully added"
});
}
});
}
});
}
});
}
else {
res.status(400).json({
message: "User already exists!"
});
}
}
});
}
exports.readUser = (req, res) => {
const readParams = {
TableName: 'User'
};
// Return all users in table using the scan() function
dynamoDB.scan(readParams, (err, data) => {
if (err) {
res.status(400).json({
message: "Could not fetch Users"
});
}
else {
res.status(200).json({
users: data.Items
});
}
});
}
exports.updateUser = (req, res) => {
const { firstName, lastName, email, password } = JSON.parse(req.body.body);
// Create new object for the purpose of updating data
let userData = {};
// Email will always be required in the Update User form, rest are optional
userData.email = email;
// Check to see if any of the fields are non-empty.
// If so, append a key to object with their value
if (firstName !== '') {
userData.firstName = firstName;
}
if (lastName !== '') {
userData.lastName = lastName;
}
if (password !== ''){
userData.password = password;
}
// Setting request parameters for verification
let requestParam = {
TableName: 'User',
Key: {
'emailAddress' : { 'S' : email }
}
}
// Check DynamoDB table to see if User exists
dynamoDB.getItem(requestParam, (err, data) => {
if (err) {
res.status(400).json({
message: "Could not find User"
});
}
else {
// If User with this email address is found, update User, else return error
if (Object.keys(data).length !== 0) {
// If update includes password, generate a salt and hash for it
if (Object.keys(userData).includes('password')){
bcrypt.genSalt(10, (err, salt) => {
if (err) {
res.status(400).json({
message: "Could not generate salt"
});
}
else {
// Hash password of the User if data was provided
bcrypt.hash(password, salt, (err, hashedPassword) => {
if (err) {
res.status(400).json({
message: "Could not generate hash"
});
}
else {
// Set values to what was provided and update password of userData object
// Pass object in for update
userData.password = hashedPassword;
let expression = '';
let expressionAttributes = {};
// Check userData object to see which attributes need to be updated for statement construction
// First name and Last name may or may not be required to be updated, formulate statement accordingly
expression = userData.firstName !== undefined ? 'SET firstName = :firstName,' : '';
expression += userData.lastName !== undefined && userData.firstName === undefined ? 'SET lastName = :lastName,' :
(userData.lastName !== undefined && userData.firstName !== undefined ? ' lastName = :lastName,' : ''),
// Password will be updated if userData key exists
expression += userData.firstName === undefined && userData.lastName === undefined ? 'SET password = :password,' : ' password = :password,';
// Date modified attribute will always be updated
expression += ' dateUpdated = :dateUpdated';
// Check to see which attributes are available and add values accordingly
if (userData.firstName !== undefined) {
expressionAttributes[':firstName'] = { 'S' : userData.firstName };
}
if (userData.lastName !== undefined) {
expressionAttributes[':lastName'] = { 'S' : userData.lastName };
}
if (userData.password !== undefined) {
expressionAttributes[':password'] = { 'S' : userData.password };
}
// Pass in the latest date value to update User information
expressionAttributes[":dateUpdated"] = { 'S' : new Date().toISOString() };
// Create object with expression and expression attribute values for User update
let updateParams = {
TableName: 'User',
Key: { 'emailAddress' : { 'S' : email }
},
UpdateExpression: expression,
ExpressionAttributeValues: expressionAttributes
}
// Update items using the updateItem() function
dynamoDB.updateItem(updateParams, (err, data) => {
if (err) {
res.status(400).json({
message: "Could not update User information"
});
}
else {
res.status(200).json({
message: "User information updated"
});
};
});
}
});
}
});
}
else {
// Set values to what was provided
// No need for salting and hashing passwords as password to update was not provided
// Pass object in userData object as is for updatelet expression = '';
let expression = '';
let expressionAttributes = {};
// Check userData object to see which attributes need to be updated for statement construction
// First name and Last name may or may not be required to be updated, formulate statement accordingly
expression = userData.firstName !== undefined ? 'SET firstName = :firstName,' : '';
expression += userData.lastName !== undefined && userData.firstName === undefined ? 'SET lastName = :lastName,' :
(userData.lastName !== undefined && userData.firstName !== undefined ? ' lastName = :lastName,' : ''),
// Password will not be updated as it is not part of the userData keys
// Date modified attribute will always be updated
expression += ' dateUpdated = :dateUpdated';
// Check to see which attributes are available and add values accordingly
if (userData.firstName !== undefined) {
expressionAttributes[':firstName'] = { 'S' : userData.firstName };
}
if (userData.lastName !== undefined) {
expressionAttributes[':lastName'] = { 'S' : userData.lastName };
}
// Pass in the latest date value to update User information
expressionAttributes[":dateUpdated"] = { 'S' : new Date().toISOString() };
// Create object with expression and expression attribute values for User update
let updateParams = {
TableName: 'User',
Key: { 'emailAddress' : { 'S' : email }
},
UpdateExpression: expression,
ExpressionAttributeValues: expressionAttributes
}
// Update DynamoDB table with requested attributes using the updateItem() function
dynamoDB.updateItem(updateParams, (err, data) => {
if (err) {
res.status(400).json({
message: "Could not update User information"
});
}
else {
res.status(200).json({
message: "User information updated"
});
};
});
}
}
else {
// User does not exist, return error response
res.status(400).json({
message: "Could not update User values, as User does not exist!"
});
}
}
});
}
exports.deleteUser = (req, res) => {
const { emailAddress } = JSON.parse(req.body.body);
// Set delete parameters
let deleteParams = {
TableName: 'User',
Key: {
emailAddress : { 'S' : emailAddress }
}
}
// Delete item using the deleteItem() function
dynamoDB.deleteItem(deleteParams, (err, data) => {
if (err) {
res.status(400).json({
message: "Could not delete User"
});
}
else {
res.status(200).json({
message: "User successfully deleted"
});
}
});
}