Can we please simplify generateMetadata function?

[gmantri]

Goals

Simplify generateMetadata function so that we don't have to jump through hoops to set the metadata.

Background

For dynamic pages where the metadata and page content depends on fetching data from external resources (e.g. database), you end up writing the data fetching logic in a separate function and call that inside in your Page and generateMetadata (assuming no fetch is involved).

To avoid multiple calls to fetch data, it is recommended that we wrap the function inside React's cache function. I see two issues with that:

1. If for some reason this function fails (let's say because of some transient error), the error result will be cached and the same error result will be displayed to the user regardless of whether that transient error is gone. Reference: https://react.dev/reference/react/cache#caveats.
2. (It may be the lack of my knowledge), but I could not find a way to invalidate that cache. Let's say the page content is updated but the user will still be shown the old data.

Proposal

Not an expert here but considering Metadata is part of the App Router pages, why can't I simply set that inside my page component. Or have another variant of generateMetadata function which will take a simple object (based on the application data) and return a Metadata object as returned currently by this function.

[threehams]

It's complicated right now because of server rendering. React 19 adds support for metadata anywhere in the component tree, but it hasn't been released yet.