Aggregator Pattern

Introduction

The Aggregator Pattern is a design pattern used in software development that allows for the collection of various elements or resources into a single cohesive unit. This pattern is particularly useful when dealing with multiple data sources or services that need to be combined into a single response or result.

Key Concepts

• Single Point of Access: The aggregator acts as a single entry point for data retrieval.
• Decoupling: Reduces dependencies between different services or data sources.
• Data Transformation: The aggregator can transform or process data before returning it.
• Performance Optimization: Can optimize calls to reduce latency.

Step-by-Step Implementation

1. Define Data Sources

Identify the various data sources that the aggregator will need to communicate with.

2. Create Aggregator Class

Implement a class that will handle the aggregation logic.

class Aggregator {
    constructor(dataSources) {
        this.dataSources = dataSources;
    }

    async fetchData() {
        const results = await Promise.all(this.dataSources.map(source => fetch(source)));
        return Promise.all(results.map(result => result.json()));
    }

    async getAggregatedData() {
        const data = await this.fetchData();
        return this.transformData(data);
    }

    transformData(data) {
        // Perform any necessary transformations
        return data;
    }
}

3. Usage

Instantiate the aggregator and use it to fetch and aggregate data.

const sources = ['https://api.example.com/data1', 'https://api.example.com/data2'];
const aggregator = new Aggregator(sources);

aggregator.getAggregatedData().then(data => {
    console.log(data);
});

Best Practices

• Keep the aggregator logic separate to maintain clean code.
• Implement error handling to manage failures in fetching data from sources.
• Optimize data fetching methods to avoid unnecessary calls.
• Use caching mechanisms if the data does not change frequently.

FAQ