Potential solution

To create an API endpoint for retrieving the current stock data, we need to establish a clear flow from the client request to the database query. This involves setting up a route to handle incoming requests, a controller to process the request and interact with the model, and a model to query the database for the required data. The solution will involve creating or modifying files to ensure that each part of this flow is correctly implemented.

How to implement

Set up the Route: In the routes/api.js file, define a new route that listens for GET requests at the endpoint /stock/current. This route will use a controller function to handle the request.

const express = require('express');
const router = express.Router();
const stockController = require('../controllers/stockController');

router.get('/stock/current', stockController.getCurrentStock);

module.exports = router;

Create the Controller Function: In the controllers/stockController.js file, implement a function named getCurrentStock. This function will use the model to retrieve the total current stock data and send it back as a JSON response.

const StockModel = require('../models/stockModel');

const getCurrentStock = async (req, res) => {
   try {
       const totalCurrentStock = await StockModel.getTotalCurrentStock();
       res.status(200).json({
           success: true,
           data: totalCurrentStock
       });
   } catch (error) {
       res.status(500).json({
           success: false,
           message: 'Failed to retrieve current stock data',
           error: error.message
       });
   }
};

module.exports = {
   getCurrentStock
};

Implement the Model Method: In the models/stockModel.js file, define a method getTotalCurrentStock that queries the database to calculate the total current stock. This example uses Mongoose for MongoDB, but you can adjust it for your specific database and ORM.

const mongoose = require('mongoose');

const stockSchema = new mongoose.Schema({
 itemName: String,
 quantity: Number,
});

const Stock = mongoose.model('Stock', stockSchema);

stockSchema.statics.getTotalCurrentStock = async function() {
 try {
   const totalStock = await this.aggregate([
     {
       $group: {
         _id: null,
         totalQuantity: { $sum: "$quantity" }
       }
     }
   ]);
   return totalStock[0]?.totalQuantity || 0;
 } catch (error) {
   throw new Error('Error retrieving total current stock: ' + error.message);
 }
};

module.exports = Stock;

Integrate the Route: Ensure that the new route is integrated into your main application file (e.g., app.js or server.js) where all routes are combined.

const express = require('express');
const app = express();
const apiRoutes = require('./routes/api');

app.use('/api', apiRoutes);

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
   console.log(`Server is running on port ${PORT}`);
});

This implementation provides a complete flow from the API endpoint to the database query, ensuring that the current stock data can be retrieved and returned to the client. Adjust the database connection and error handling as needed for your specific application environment.

Click here to create a Pull Request with the proposed solution

Files used for this task:

Changes on routes/api.js

To add a new route for the 'get current stock data' endpoint in the `routes/api.js` file, follow these steps: 1. **Import Necessary Modules**: You will need to import the Express module and the stock controller that will handle the logic for retrieving the current stock data. 2. **Initialize Router**: Use Express to create a new router instance. 3. **Define the Route**: Add a new route that listens for GET requests on the desired endpoint path (e.g., `/stock/current`). This route should use the appropriate method from the stock controller to handle the request. 4. **Export the Router**: Ensure the router is exported so it can be used by the main application. Here's a basic implementation outline: ```javascript const express = require('express'); const router = express.Router(); const stockController = require('../controllers/stockController'); // Define the route for getting current stock data router.get('/stock/current', stockController.getCurrentStockData); // Export the router module.exports = router; ``` Make sure that the `stockController.js` file has a method named `getCurrentStockData` that handles the logic for fetching and returning the current stock data. Additionally, ensure that this route is properly integrated into your main application file (e.g., `app.js` or `server.js`) where all routes are combined.

Changes on controllers/stockController.js

To implement the function in `controllers/stockController.js` for processing the request and returning the current stock data, follow these steps: 1. **Define the Function**: Create a function named `getCurrentStock` that will handle the incoming request for current stock data. 2. **Import Necessary Modules**: Ensure you import any necessary modules or models, such as the `stockModel`, which will be used to interact with the database. 3. **Retrieve Data**: Use the method from `stockModel` to fetch the total current stock data from the database. 4. **Send Response**: Format the retrieved data as needed and send it back in the response. Here is a basic implementation outline for `controllers/stockController.js`: ```javascript // Import the stock model const StockModel = require('../models/stockModel'); // Define the controller function const getCurrentStock = async (req, res) => { try { // Retrieve the total current stock from the database const totalCurrentStock = await StockModel.getTotalCurrentStock(); // Send the retrieved data as a response res.status(200).json({ success: true, data: totalCurrentStock }); } catch (error) { // Handle any errors that occur during the process res.status(500).json({ success: false, message: 'Failed to retrieve current stock data', error: error.message }); } }; // Export the function to be used in routes module.exports = { getCurrentStock }; ``` Make sure to adjust the function and error handling as per your application's specific requirements and structure.

Changes on models/stockModel.js

To address the task for the `models/stockModel.js` file, you need to implement a method that retrieves the total current stock from the database. Here's a practical proposal for how you can achieve this: 1. **Define the Stock Model**: If not already defined, create a schema for the stock data that represents how stock information is stored in your database. 2. **Implement the Method**: Add a method to the stock model that queries the database to calculate and return the total current stock. This method will likely involve aggregating stock quantities from the relevant database table. Here's a basic example of what the implementation might look like using a hypothetical ORM like Mongoose for MongoDB: ```javascript // models/stockModel.js const mongoose = require('mongoose'); // Define the stock schema const stockSchema = new mongoose.Schema({ itemName: String, quantity: Number, // Add other relevant fields }); // Create the stock model const Stock = mongoose.model('Stock', stockSchema); // Method to retrieve total current stock stockSchema.statics.getTotalCurrentStock = async function() { try { const totalStock = await this.aggregate([ { $group: { _id: null, totalQuantity: { $sum: "$quantity" } } } ]); return totalStock[0]?.totalQuantity || 0; } catch (error) { throw new Error('Error retrieving total current stock: ' + error.message); } }; module.exports = Stock; ``` ### Key Points: - **Schema Definition**: Ensure the schema accurately reflects the structure of your stock data. - **Aggregation**: Use an aggregation query to sum up the quantities of all stock items to get the total current stock. - **Error Handling**: Implement error handling to manage potential database errors gracefully. This method will be used by the controller to fetch the total current stock data when the API endpoint is called. Adjust the implementation details based on your specific database and ORM setup.

csharpnetframwork / ShopCode

Create Api Endpoint for get current Stock data #6

Potential solution

How to implement