Dynamic Revalidation Times Based on Runtime Data for Enhanced Caching Strategies

[RandallRock123]

Goals

1.Provide more adaptive and granular control over caching and revalidation strategies in Next.js.
2.Reduce server load and improve application performance by tailoring data fetching intervals based on actual data characteristics.
3.Enhance the developer’s ability to manage data freshness more responsively, especially for dynamic or sensitive content.

Non-Goals

1.Overhaul of the existing static revalidation mechanism.
2.Introduction of new caching methodologies unrelated to fetch API enhancements.
3.Automatic management of revalidation times without developer input.

Background

Currently, Next.js supports static revalidation times through the revalidate option, which sets a fixed interval for data fetching. This static approach does not account for the context or the nature of the data returned, which can lead to either unnecessary requests or outdated data being served. While some developers use custom server-side logic to handle dynamic data needs, there's no integrated way in Next.js to dynamically adjust revalidation times based on the fetched data itself. This feature would fill that gap, allowing developers to implement more precise caching strategies directly within their Next.js applications.

Proposal

The feature should be implemented as a new option called dynamicRevalidate within the fetch configuration in Next.js. This option would allow developers to pass a function that takes the fetch result as an argument and returns a dynamic revalidation time in seconds. The existing revalidate option would serve as a fallback if the dynamic function is not specified or fails, ensuring backward compatibility.

Example usage:

const response = await fetch('https://api.example.com/data', {
  next: {
    revalidate: 3600,  // Fallback static revalidation time if dynamicRevalidate throw error
    dynamicRevalidate: (res) => {
      if (res.ok) {
        // custom logic to calc revalidate seconds based on fetch response.
        return customRevalidationTimeBasedOnFetchResponse
      }
      return 600;  // fallback value
    }
  }
});