MultyDataloader

MultyDataloader

MultyDataloader is a utility class that provides dynamic creation and caching of DataLoader instances based on different parameters. This allows for efficient batching and caching of data loading requests, reducing duplicate queries and optimizing data fetching.

Installation

To install MultyDataloader using npm:

npm install multydataloader

Or using yarn:

yarn add multydataloader

Usage

Basic Example

First, import the necessary modules and types:

import DataLoader from "dataloader";
import MultyDataloader, { MultyDataloaderBatchLoadFn } from "multydataloader";

Define a batch loading function that uses the provided parameters and keys to load data. Then, create an instance of MultyDataloader and use it to load data with different parameters:

const exampleBatchLoadFn: MultyDataloaderBatchLoadFn = (params) => async (keys) => {
  // Use params and keys to load data
  return keys.map(key => `Data for ${key} with params ${JSON.stringify(params)}`);
};

const loader = new MultyDataloader(exampleBatchLoadFn);

(async () => {
  const data1 = await loader.load('key1', { param1: 'value1', param2: 'value2' });
  console.log(data1); // Output: "Data for key1 with params {"param1":"value1","param2":"value2"}"
})();

API

MultyDataloader<R>

Constructor

constructor(batchLoadFn: MultyDataloaderBatchLoadFn<R>)

• batchLoadFn: A function that generates a batch load function for DataLoader instances. It takes an optional params object and returns a DataLoader.BatchLoadFn.

Methods

load(mpid: unknown, params?: Params): Promise<R>

Loads data using the specified mpid and optional params.

• mpid: The key to be loaded by the DataLoader.
• params: Optional parameters to customize the DataLoader instance.

private getDataloader(key: string, params?: Params): DataLoader<unknown, R>

Gets an existing DataLoader instance or creates a new one based on the provided key and params.

private objectToKey(obj: Params): string

Generates a unique key string from the provided params object by sorting its keys and creating a SHA-256 hash.

License

This project is licensed under the MIT License. See the LICENSE file for details.