The infuseData Callback

The Challenge

When Replyke fetches data for a feed, it retrieves only the information it manages internally. While this is sufficient for many applications, there are cases where entities need additional external data to be meaningful. For example:

• A product entity might need inventory details from an external inventory management system.

Without a mechanism to merge external data into Replyke’s entities, developers are left with incomplete data objects, limiting the application’s functionality and user experience.

The Solution

The infuseData callback provides a seamless way to integrate external data into entities fetched by Replyke. This function is passed to the FeedProvider and is invoked for each entity in the feed. The infuseData function:

1. Receives a referenceId for each entity.
2. Fetches additional data for that entity from an external source (e.g., another database or API).
3. Merges the fetched data with the entity, creating a complete data object that includes both Replyke-managed and externally sourced information.

This approach ensures that developers can leverage Replyke’s powerful feed capabilities while maintaining access to essential external data.

How It Works

Internally, the useInfusedData hook handles the logic for merging data. For each entity:

• It checks if the external data for the entity is already cached to avoid redundant fetches.
• If not, it uses the provided infuseData function to fetch the required data.
• The fetched data is then merged with the entity, and the complete object is returned in the infusedEntities array.

The entities array remains “pure,” containing only the data fetched by Replyke. The infusedEntities array provides the enriched versions of these entities.

Example

Here is a practical example of how to use the infuseData callback:

import React from 'react';
import { FeedProvider, useFeed } from 'replyke';
 
const fetchInventoryData = async (referenceId: string) => {
  try {
    const response = await fetch(`/api/inventory/${referenceId}`);
    if (!response.ok) {
      throw new Error('Failed to fetch inventory data');
    }
    return await response.json();
  } catch (error) {
    console.error(`Error fetching inventory data for ${referenceId}:`, error);
    return null;
  }
};
 
const ProductFeed = () => {
  const {
    infusedEntities,
    loadMore,
    resetEntities,
    loading,
    hasMore,
  } = useFeed();
 
  return (
    <div>
      <h1>Product Feed</h1>
      <ul>
        {infusedEntities.map((entity) => (
          <li key={entity.referenceId}>
            <h2>{entity.title}</h2>
            <p>Stock: {entity.infusion.stock}</p>
            <p>Price: ${entity.infusion.price}</p>
          </li>
        ))}
      </ul>
      {loading && <p>Loading...</p>}
      {hasMore && <button onClick={loadMore}>Load More</button>}
      <button onClick={resetEntities}>Refresh Feed</button>
    </div>
  );
};
 
const App = () => (
  <FeedProvider infuseData={fetchInventoryData}>
    <ProductFeed />
  </FeedProvider>
);
 
export default App;
 

Key Takeaways

• The infuseData callback bridges the gap between Replyke’s feed data and your application’s external data requirements.
• It ensures that entities can be enriched with external data dynamically.
• The process is efficient, leveraging caching to minimize redundant fetches.

This feature empowers developers to create rich, data-complete applications while maintaining the flexibility and power of Replyke feeds.