A Node.js service for managing car auctions, including placing bids, ending auctions, selecting winners, and generating reports.
npm install saksh-car-auctionsaksh-car-auction class provides a comprehensive solution for managing car auctions, including placing bids, updating bids, fetching bids, ending auctions, and selecting winners. This class is built using Node.js and MongoDB, and it leverages event-driven programming with the EventEmitter module.
EventEmitter for handling events, making it easy to extend and customize.
bash
npm i saksh-car-auction
`
Usage
$3
Here's an example demonstrating the entire flow of placing a bid, updating a bid, placing more bids from different users, selecting the highest bid, ending the auction, and selecting the winning bidder.
`javascript
const mongoose = require('mongoose');
const SakshCarAuction = require('./index');
// Connect to MongoDB
mongoose.connect('mongodb://localhost:27017/auctionDB', { useNewUrlParser: true, useUnifiedTopology: true })
.then(() => console.log('MongoDB connected'))
.catch(err => console.error('MongoDB connection error:', err));
// Example user IDs
const userId1 = 'user123';
const userId2 = 'user456';
const userId3 = 'user789';
// Create instances of SakshCarAuction for different users
const auction1 = new SakshCarAuction(userId1);
const auction2 = new SakshCarAuction(userId2);
const auction3 = new SakshCarAuction(userId3);
// Example callback function for bid validation
const validateBid = (carId, bidAmount) => {
return bidAmount > 0; // Example validation: bid amount must be greater than 0
};
// Example callback function for permission validation
const validatePermission = (userId, resourceId, action) => {
// Add your permission validation logic here
if (action === "updatebid" || action === "selectwinner" || action === "closebidding") {
return userId === 'user123'; // Example validation: only user123 has permission for these actions
}
return true;
};
// Function to get car ID
async function getCarId() {
return "66ebd87c0cab7b7737ecda1a"; // Example car ID
}
// Event listeners
auction1.on('bidPlaced', (data) => {
console.log('Event: bidPlaced', data);
});
auction1.on('bidUpdated', (data) => {
console.log('Event: bidUpdated', data);
});
auction1.on('bidDeleted', (data) => {
console.log('Event: bidDeleted', data);
});
auction1.on('auctionEnded', (data) => {
console.log('Event: auctionEnded', data);
});
auction1.on('winnerSelected', (data) => {
console.log('Event: winnerSelected', data);
});
// Consolidated function to demonstrate the entire flow
async function runAuctionFlow() {
const carId = await getCarId();
// Step 1: Place a Bid
const bidAmount1 = 5000;
const placeBidResult = await auction1.sakshPlaceBid(carId, bidAmount1, validateBid);
console.log('Place Bid:', placeBidResult);
const bidId = placeBidResult.data ? placeBidResult.data.bidId : null;
// Step 2: Update the Bid
if (bidId) {
const newBidAmount = 6000;
const updateBidResult = await auction1.sakshUpdateBid(bidId, newBidAmount, validatePermission);
console.log('Update Bid:', updateBidResult);
}
// Step 3: Place More Bids from Different Users
const bidAmount2 = 7000;
const bidAmount3 = 8000;
const placeBidResult2 = await auction2.sakshPlaceBid(carId, bidAmount2, validateBid);
console.log('Place Bid from User 2:', placeBidResult2);
const placeBidResult3 = await auction3.sakshPlaceBid(carId, bidAmount3, validateBid);
console.log('Place Bid from User 3:', placeBidResult3);
// Step 4: Select the Highest Bid
const highestBidResult = await auction1.sakshGetHighestBid(carId);
console.log('Highest Bid:', highestBidResult);
// Step 5: End the Auction
const endAuctionResult = await auction1.sakshEndAuction(carId, validatePermission);
console.log('End Auction:', endAuctionResult);
// Step 6: Select the Winning Bidder
const selectWinnerResult = await auction1.sakshSelectWinner(carId, validatePermission);
console.log('Select Winner:', selectWinnerResult);
// Close the MongoDB connection
mongoose.connection.close();
}
runAuctionFlow();
`
Functions
- sakshPlaceBid(carId, bidAmount, validateBidCallback): Places a bid on a car.
- Parameters:
- carId: The ID of the car.
- bidAmount: The amount of the bid.
- validateBidCallback: A callback function to validate the bid.
- Returns: An object containing the success status, message, and bid data.
- sakshUpdateBid(bidId, newBidAmount, validatePermissionCallback): Updates an existing bid.
- Parameters:
- bidId: The ID of the bid.
- newBidAmount: The new bid amount.
- validatePermissionCallback: A callback function to validate user permissions.
- Returns: An object containing the success status, message, and updated bid data.
- sakshDeleteBid(bidId, validatePermissionCallback): Deletes an existing bid.
- Parameters:
- bidId: The ID of the bid.
- validatePermissionCallback: A callback function to validate user permissions.
- Returns: An object containing the success status, message, and deleted bid data.
- sakshEndAuction(carId, validatePermissionCallback): Ends the auction for a car.
- Parameters:
- carId: The ID of the car.
- validatePermissionCallback: A callback function to validate user permissions.
- Returns: An object containing the success status, message, and auction data.
- sakshSelectWinner(carId, validatePermissionCallback, userId = null): Selects the winning bid for a car.
- Parameters:
- carId: The ID of the car.
- validatePermissionCallback: A callback function to validate user permissions.
- userId: (Optional) The ID of the user to select as the winner.
- Returns: An object containing the success status, message, and winner data.
- sakshGetHighestBid(carId): Fetches the highest bid for a car.
- Parameters:
- carId: The ID of the car.
- Returns: An object containing the success status, message, and highest bid data.
$3
`javascript
const express = require('express');
const mongoose = require('mongoose');
const SakshCarAuction = require('./index');
const app = express();
const port = 3000;
// Middleware to parse JSON
app.use(express.json());
// Connect to MongoDB
mongoose.connect('mongodb://localhost:27017/auctionDB', {
useNewUrlParser: true,
useUnifiedTopology: true
})
.then(() => console.log('MongoDB connected'))
.catch(err => console.error('MongoDB connection error:', err));
// Example user IDs
const userId1 = 'user123';
const userId2 = 'user456';
const userId3 = 'user789';
// Create instances of SakshCarAuction for different users
const auction1 = new SakshCarAuction(userId1);
const auction2 = new SakshCarAuction(userId2);
const auction3 = new SakshCarAuction(userId3);
// Example callback function for bid validation
const validateBid = (carId, bidAmount) => {
return bidAmount > 0; // Example validation: bid amount must be greater than 0
};
// Example callback function for permission validation
const validatePermission = (userId, resourceId, action) => {
// Add your permission validation logic here
if (action === "updatebid" || action === "selectwinner" || action === "closebidding") {
return userId === 'user123'; // Example validation: only user123 has permission for these actions
}
return true;
};
// Route to place a bid
app.post('/placeBid', async (req, res) => {
const { carId, bidAmount, userId } = req.body;
const auction = new SakshCarAuction(userId);
const result = await auction.sakshPlaceBid(carId, bidAmount, validateBid);
res.json(result);
});
// Route to update a bid
app.put('/updateBid', async (req, res) => {
const { bidId, newBidAmount, userId } = req.body;
const auction = new SakshCarAuction(userId);
const result = await auction.sakshUpdateBid(bidId, newBidAmount, validatePermission);
res.json(result);
});
// Route to end the auction
app.post('/endAuction', async (req, res) => {
const { carId, userId } = req.body;
const auction = new SakshCarAuction(userId);
const result = await auction.sakshEndAuction(carId, validatePermission);
res.json(result);
});
// Route to select the winner
app.post('/selectWinner', async (req, res) => {
const { carId, userId } = req.body;
const auction = new SakshCarAuction(userId);
const result = await auction.sakshSelectWinner(carId, validatePermission);
res.json(result);
});
// Start the server
app.listen(port, () => {
console.log(Server running at http://localhost:${port});
});
`
Usage
1. Start the Server:
`bash
node server.js
`
2. Place a Bid:
`bash
curl -X POST http://localhost:3000/placeBid -H "Content-Type: application/json" -d '{"carId": "66ebd87c0cab7b7737ecda1a", "bidAmount": 5000, "userId": "user123"}'
`
3. Update a Bid:
`bash
curl -X PUT http://localhost:3000/updateBid -H "Content-Type: application/json" -d '{"bidId": "bid123", "newBidAmount": 6000, "userId": "user123"}'
`
4. End the Auction:
`bash
curl -X POST http://localhost:3000/endAuction -H "Content-Type: application/json" -d '{"carId": "66ebd87c0cab7b7737ecda1a", "userId": "user123"}'
`
5. Select the Winner:
`bash
curl -X POST http://localhost:3000/selectWinner -H "Content-Type: application/json" -d '{"carId": "66ebd87c0cab7b7737ecda1a", "userId": "user123"}'
`
This example demonstrates how to integrate the SakshCarAuction` class into an Express.js application, providing routes for the main auction functionalities. Let me know if you need any further adjustments or additional features!