@arunvaradharajalu/common.mongodb-paginator

This package provides MongoDB pagination utilities for efficiently retrieving large datasets in parts.

Installation

To install the package, use npm:

npm install @arunvaradharajalu/common.mongodb-paginator

Usage

Basic Usage

Here is an example of how to use the MongoDB paginator in your project:

import { MongoDBPaginatorImpl, PaginationOptions, PaginationWithIdOptions } from '@arunvaradharajalu/common.mongodb-paginator';
import { MongoDBRepository } from '@arunvaradharajalu/common.mongodb-api';

// Initialize MongoDB repository
const mongodbRepository = new MongoDBRepository(/* MongoDB connection details */);

// Initialize paginator
const paginator = new MongoDBPaginatorImpl(mongodbRepository);

// Define pagination options
const options = new PaginationOptions();
options.pageIndex = 0; // Page number
options.pageSize = 10; // Number of documents per page
options.sortField = 'name'; // Field to sort by
options.sortType = SortTypes.ASC; // Sort order (ascending or descending)

// Define a filter
const filter = { /* your filter criteria */ };

// Retrieve paginated data
paginator.find('yourCollectionName', filter, options)
  .then(result => {
    console.log('Documents:', result.docs);
    console.log('Total Count:', result.count);
  })
  .catch(error => {
    console.error('Error fetching paginated data:', error);
  });

Advanced Usage with Aggregation

The paginator also supports MongoDB aggregation with pagination:

const pipeline = [
  { $match: { /* your match criteria */ } },
  { $group: { _id: '$field', total: { $sum: '$value' } } }
];

paginator.aggregate('yourCollectionName', pipeline, options)
  .then(result => {
    console.log('Documents:', result.docs);
    console.log('Total Count:', result.count);
  })
  .catch(error => {
    console.error('Error fetching aggregated paginated data:', error);
  });

Pagination with Index

You can also paginate using an index field other than _id:

const paginationWithIdOptions = new PaginationWithIdOptions();
paginationWithIdOptions.pageSize = 5;
paginationWithIdOptions.sortField = 'name';
paginationWithIdOptions.sortType = SortTypes.ASC;

paginator.findWithIndex('yourCollectionName', filter, paginationWithIdOptions)
  .then(result => {
    console.log('Documents:', result.docs);
    console.log('Total Count:', result.count);
  })
  .catch(error => {
    console.error('Error fetching paginated data with index:', error);
  });

API Reference

Classes

MongoDBPaginatorImpl:

• Constructor: new MongoDBPaginatorImpl(mongodbRepository: MongoDBRepository)
• Methods:
  • find(collectionName: string, filter: Filter<Document>, options: PaginationOptions): Promise<{ docs: Document[], count: number }>
  • aggregate(collectionName: string, pipeline: Document[], options: PaginationOptions): Promise<{ docs: any[], count: number }>
  • findWithIndex(collectionName: string, filter: Filter<Document>[], options: PaginationWithIdOptions): Promise<{ docs: Document[], count: number }>
  • aggregateWithIndex(collectionName: string, pipeline: Document[], options: PaginationWithIdOptions): Promise<{ docs: any[], count: number }>

PaginationOptions:

• Properties:
  • pageIndex: number (default: 0)
  • pageSize: number (default: 10)
  • sortType: SortTypes (default: SortTypes.DESC)
  • sortField: string (default: '_id')
  • collationOptions: CollationOptions | null (default: null)

PaginationWithIdOptions:

• Properties:
  • type: PaginatorTypes (default: PaginatorTypes.FORWARD)
  • pageSize: number (default: 5)
  • sortType: SortTypes (default: SortTypes.ASC)
  • sortField: string (default: '_id')
  • sortFieldValue: string | null (default: null)
  • id: string | null (default: null)
  • collationOptions: CollationOptions | null (default: null)

Running Tests

To run the tests, use:

npm test

The test results will be generated in an HTML report with the title "MongoDB Paginator Test Report".

Contributing

Contributions are welcome! Please feel free to submit a pull request or open an issue for bug fixes, improvements, or new features.

Author

Arun Varadharajalu

License

This project is licensed under the ISC License.