How to implement pagination in a Node.js application

Implementing pagination in a Node.js application typically involves handling the logic for fetching and displaying a subset of data at a time. Here's a general guide on how to implement pagination:

1. Install Required Packages

If you haven't already, you may need to install packages like Express and Mongoose (assuming you're working with MongoDB).

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npm install express mongoose

2. Set Up Express

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const express = require('express');
const mongoose = require('mongoose');
const app = express();
const port = 3000;

mongoose.connect('mongodb://localhost/your_database', { useNewUrlParser: true, useUnifiedTopology: true });

// Define your mongoose model and schema
const YourModel = mongoose.model('YourModel', yourSchema);

app.get('/items', async (req, res) => {
  try {
    const page = parseInt(req.query.page) || 1;
    const limit = parseInt(req.query.limit) || 10;

    const skip = (page - 1) * limit;

    const items = await YourModel.find().skip(skip).limit(limit);
    const totalItems = await YourModel.countDocuments();

    const totalPages = Math.ceil(totalItems / limit);

    res.json({
      items,
      currentPage: page,
      totalPages,
    });
  } catch (error) {
    console.error(error);
    res.status(500).json({ error: 'Internal Server Error' });
  }
});

app.listen(port, () => {
  console.log(`Server is running on port ${port}`);
});

3. Client-side Integration

On the client side, you would make a request to your server, specifying the desired page and limit as query parameters. For example, using JavaScript fetch:

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const page = 2;
const limit = 10;

fetch(`/items?page=${page}&limit=${limit}`)
  .then(response => response.json())
  .then(data => {
    console.log(data);
    // Handle data (e.g., update UI)
  })
  .catch(error => console.error(error));

4. Display Pagination UI

In your front-end, you'll want to display pagination controls to allow users to navigate through different pages. You can create buttons or links to navigate to the next and previous pages.

This is a basic example, and you may need to adjust it based on your specific requirements and the frontend library or framework you're using.

Keep in mind that this example assumes you're using MongoDB with Mongoose, and you may need to adjust it for other databases.

Adjust the code based on your specific use case, database, and requirements.